# TUBE Facts and Info by MartyStrat54



## MartyStrat54

Hello MF members. As we all know, there are always a lot of threads pertaining to tubes. I would like to just share a few things and I hope it will be helpful.

First off, a lot of questions are directed at the "high gain" Marshall's like a DSL, TSL or 410. Please be aware that these amps get all of their tone out of the preamp stage. I cringe when I hear someone with a DSL asking how they can get "better power tube distortion?" If you have a DSL and the power tubes are distorting, I don't think you will like what you hear.

DSL amps (and other high gain Marshall's) use four (or more) preamp tubes. V1 and V2 are the gain stages. V3 (A and B) are the Tone Stack and Cathode Follower. V4 is the Phase Inverter tube for the power tube section.

V1 will make the most noticeable difference in tone and gain. I always say that you want to put your very best tube in V1. The DSL can handle a pretty hot 12AX7 without farting out. I used to be a little conservative about the V1 tube I used, but over the past year, I tend to go with a hotter tube if it fits the player's needs. I use a more moderate tube for those whose playing style dictates it.

Note: In Plexi's, JMP's and JCM 2203/04's, V1 is the main tube for gain. Half of V2 needs to be considered as well, so I still recommend a good tube for V2.

Here is something that has me perplexed. Current production tubes are not that expensive. I think any guitarist that has more than two years playing under their belt needs to have a nice stash of tubes to fall back on and also to experiment with for tone. I think every player should have a budget that allows for multiple 12AX7 tubes. They shouldn't be purchased "as needed." I have said this before, "Every tube amp player should have a complete set of tubes to be used for backup purposes or troubleshooting."

If you own a Marshall or other tube amp and you are running old tubes, because you can't afford a new set, you run the risk of damaging your amp. If you are lucky, a fuse will pop when a power tube blows. However, I have seen more serious damage such as fried valve sockets and burned components. Again, all tube amp owners should have a complete backup set of tubes.

Now back to 12AX7's. You should try and get yourself a JJ ECC83 (same as a 12AX7). Also, a Tung-Sol and a Mullard RI. You can round out your set with a Shuguang (Chinese) 12AX7. The Shuguang's are usually loved because they are high gain and are a favorite with metal players where a good clean isn't a must.

Most of the guys I hang with have 30 to 40 12AX7's. Enough to last them for a good long while. Most of these tubes were bought over a three year period. Most of these tubes are NOS. However, I won't go into that, because most of you use current production (CP) tubes. I think a good player would have two each of the preamp tubes I have listed. Having some Electro-Harmonix tubes handy would be good also. The EH tubes can be used as an economical replacement for V3 and V4 (especially the PI tube). 

To "roll" tubes in a high gain amp, you want to have V3 and V4 selected. Therefore, take a couple of EH's and put them in those slots. Put a Mullard RI in V2 and then roll the JJ, the Tung-Sol, Shuguang and even another Mullard in V1. Once you find the one you like, pull V2 and roll your tubes in V2. Once you find the tube you like, then you have your V1 through V4 selected. If you want to get picky, try rolling V3 and then V4. You might notice a very slight difference in tone by rolling these slots. My friends and I like to run a lopsided, high gain tube in the PI. This is because the power section is asymmetrical by nature and a lopsided PI tube will help enhance this. An amp with an asymmetrical signal has a lot of even order harmonics and this is what you want. This goes against what EURO TUBES states. They push their customers towards a "balanced" PI tube. Trust me, you don't need this. I will say that there is a small difference in tone between a lopsided tube and a regular one, but if you are used to rolling tubes, you will hear a small difference.

Power tubes tend to sound similar to each other when they are cranked. I run NOS power tubes and CP as well. A while back I did a review on how Sylvania Fat Boy 6CA7's (same as an EL34) compared against EH 6CA7's. At lower to moderate volumes, the NOS were better, but going above 5 on the Master Volume they both started sounding very close. I will say that there are some cheap power tubes that are thin sounding no matter what the volume level. I bring this up, because power tubes in high gain amps are designed to be ran "clean." If you use a cheap power tube, you will notice it regardless of the volume level. Look for a well made tube that are frequently recommended. Stay away from the el cheapo tubes. It's just not worth the heartache it will cause.

In closing, preamp tubes will make the most change in your tone. Power tubes just add a little. You should own a complete backup set of tubes for your amp. You should know that V1 is the most important preamp tube. For the best sound you can get out of your amp, V1 should be tested for microphonics. You'll want V1 to be as quiet as possible. Some tube companies charge $2 to test for microphonics and high gain. This is well worth the price for a V1 tube.

Remember, asking about which CP tube is best should be answered by YOU. Buy some and try them. I had a customer recently tell me that he had some power tubes that didn't sound right to him. However, he swapped V1 and the power tubes kicked butt. Tubes that sound good in a 2203 may not sound as good in a DSL. You are limited to the tones you can get with CP tubes. (Yes, NOS tubes offer more tone shaping compared to CP.)

For the most part, rolling tubes is like the icing on the cake. If you are happy with your amps general tone, the speakers you use and the guitar/pickups that you use, then rolling tubes is like the final piece of the tone puzzle.

I hope that you found this to be of some help.


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## BluesRocker

Great read Marty! 

Thanks for the info!


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## Adwex

Great article Marty.


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## solarburn

Good stuff Marty. We sure had fun discovering what tubes can/won't do in our amps. Good times!


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## NewReligion

Great read, thanks. I've been fine tuning my amps this way for years but never really thought about sharing the data. Well done.

David


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## Purgasound

Marty's the man.


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## SmokeyDopey

Yes thank you. I will take your advice and buy a few backup 12AX7s and ECC83s.


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## chuckharmonjr

Excellent article Marty. Very informative and well written. Thanks.


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## tonefreak

Awesome post Marty... I will be spending quite a lot of spare cash (whats that???) on tubes this summer... it's been over a year since my amps had tubes, and right now it's just got JJ's all through... so it's time to roll some tubes.

gotta buy some first.


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## pluto

Very nice info on tubes !!

I consider a tube as another electrical element. NOS tubes were industrial production, and definitely nobody was thinking of guitar amps when the production line was designed. Why nowadays this cannot be reproduced in detail ?

Also my experience with preamp tubes is that if you swap them too often you will run into the problems with the tube socket contacts. Or maybe it is possible to buy some special "locking" tube sockets ?

I have 4210 myself, and for me Tungsol short plate is ok in V1, better than Sovtek long plate. I don't have any NOS tubes.


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## LPMarshall hack

Thanks Marty...good to see you back on here!


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## SmokeyDopey

Question before I do anything...

I have an amp that has 12AX7s in the pre amp, and another amp with ECC83s in the pre amp. 
Can I just swap these, are they the same format basically? I heard the ECC83s are the European version of the 12AX7s, but will it work if I swap V1 preamps with both these amps?
Thanks


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## GIBSON67

SmokeyDopey said:


> Question before I do anything...
> 
> I have an amp that has 12AX7s in the pre amp, and another amp with ECC83s in the pre amp.
> Can I just swap these, are they the same format basically? I heard the ECC83s are the European version of the 12AX7s, but will it work if I swap V1 preamps with both these amps?
> Thanks




ECC83's and 12AX7's are the same tubes. You can swap without any fear.


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## SmokeyDopey

GIBSON67 said:


> ECC83's and 12AX7's are the same tubes. You can swap without any fear.


 
Great, just wanted to make sure.
Thanks!


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## rads

nice article Marty, thanks....


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## V-man

I have been doing a lot of thinking on the subject lately, and this is a great subject. 

Right now I have these ECC83s/12AX7s:

1 ???
2 MIH Amperex ECC83s
3 Marshall-branded ECC83s (circa 1993)
3 JJ 12AX7s 
6 Tung Sol 12AX7s
7 Mullard (original) ECC83s


The JCM 800 1992 had the ??? & Amperexs, the JCM 900 4100 had the Marshalls in it, and the 2550 had the JJs. I replaced the 1992 & 4100 with new Tung Sols, but now I am wondering how to set the amps up with all the tube options.

V1 Mullard V2&V3 Tung Sols all around? All Mullard on the Jube?

I have 24 preamp tubes and 9 sockets. Suggestions for one or more of my amps?


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## Wilder Amplification

pluto said:


> Or maybe it is possible to buy some special "locking" tube sockets ?



Just what we need...ZIF valve sockets. 

Here's a scenario that irritates the living fuck out of me...customer brings you an amp. You find a foil wrapped HT fuse, all screen resistors are blown and maybe an arc'ed socket or two. Luckily the OT wasn't taken out. So you call him and tell him about the blown small components. You then explain that foil wrapping a fuse is a BIG no-no, then proceed to inform them that their power valves are blown and in severe need of replacement. Response that sends the blood boiling (not word for word but something along these lines) -

"But it can't be the valves! I can't afford a new set of valves right now!"

WTF?!? Why do people respond with this shit? What you think we're gonna respond with something like "Oh well then your current valves will totally work."? You think your valves will simply feel sorry for your financial situation and just start working fine again?

So you tell them the importance of owning a spare set of valves or even a spare amp, and they act as if you've told them the absolute most rude thing in the world and walk away insulted to no end.

Guys...seriously. When you can afford a new set of valves, act like your amp needs them and go through the motions you'd go through when replacing the valves (up to and including the part where you actually place the order for them), but instead of actually installing the new valves just simply keep them handy. That way when one fails you've got spares on the ready.

Now of course there are those who can't ever afford them but want that superior tone and think they shouldn't have to pay for it and that it's not fair that those who can afford it have it and they don't. Cheap tone ain't good and good tone ain't cheap. Just like having to pay more for a hot rod vs a daily driver car, you gotta pay more for a high end valve amp vs a lower level amp.


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## MartyStrat54

V-man said:


> I have been doing a lot of thinking on the subject lately, and this is a great subject.
> 
> Right now I have these ECC83s/12AX7s:
> 
> 1 ???
> 2 MIH Amperex ECC83s
> 3 Marshall-branded ECC83s (circa 1993)
> 3 JJ 12AX7s
> 6 Tung Sol 12AX7s
> 7 Mullard (original) ECC83s
> 
> 
> The JCM 800 1992 had the ??? & Amperexs, the JCM 900 4100 had the Marshalls in it, and the 2550 had the JJs. I replaced the 1992 & 4100 with new Tung Sols, but now I am wondering how to set the amps up with all the tube options.
> 
> V1 Mullard V2&V3 Tung Sols all around? All Mullard on the Jube?
> 
> I have 24 preamp tubes and 9 sockets. Suggestions for one or more of my amps?



You have some nice tubes, "but" only if they are still good. What you need to do is find someone with a professional tube tester. Find out what the Amperex and Mullards test at. These are the tubes you want to use in V1 of your amps. Since you have so many Mullards, I would run two of them in the JCM 800 1992 and then a JJ or similar CP tube in the PI slot. Same for the 2550. The 4100 is not as sensitive to preamp tubes, but since you have so many nice ones, stick a Mullard in V1 and a Tung-Sol in V2. Again, you can go with just about anything in the V3 slot (PI).

Going this route saves some of the good tubes for future spares.


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## chuckharmonjr

Jon you are dead square on about having a spare set. I made a small plastic box into a tube holder by going to Hobby Lobby and spending like 10 bucks total for a plastic hobby box and some foam. Some cutting, some gluing...and I carry a full set of power valves and 6 pre-amp tubes in my cord bag everywhere I go.


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## chuckharmonjr

It aint the prettiest thing in the world...but it works.....


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## RiverRatt

Good post Marty! This needs a sticky.


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## ckr1231

I became completely addicted to tone chasing about a year ago. I keep a journal of what exact tubes I used on a certain date to get a certain tone, sound and feel. I have experimented with this like a drug crazzed lunitic. These notes I keep describe about as much as I can write down.
After doing this several times, I came to a combination of tubes (preamp and power ) that has helped ease me off of the tone chasing addiction. I now have 2 spare sets of these tubes (preamp and power) to replace the combination of tubes I came up with.
Man, I am glad I have kept notes with dates to help me remember the earlier attempts that I did not care for. I number the tube boxes V1, V2 ect. This is very helpful to know exactly how it worked with the notes in the journal.
Anyhow--compressed air in a can and elktra-klean is a must for anyone who becomes addicted to tone chasing and rolling tubes.


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## Adwex

Jeez, you guys are obsessed. 
I have a handful of tubes that I've accumulated over the years, but I never took notes on their tone, or built a padded box for them.


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## chuckharmonjr

Adwex said:


> Jeez, you guys are obsessed.
> I have a handful of tubes that I've accumulated over the years, but I never took notes on their tone, or built a padded box for them.



LOL...Adam...thats in case Im at a gig and lose a tube, bud. Rare event but possible. That set goes with me in my cord bag. Ive got a multimeter and an alignment tool in there too.


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## Adwex

chuckharmonjr said:


> LOL...Adam...thats in case Im at a gig and lose a tube, bud. Rare event but possible. That set goes with me in my cord bag. Ive got a multimeter and an alignment tool in there too.



I've got a survival bag too with a bunch of stuff...tubes, fuses, screwdrivers, strings, picks, all sorts of adapters, cables, multimeter, batteries, power strip, wire cutters, etc. You never know what you're gonna need. I blew a fuse at one gig during setup, I had to take the amp chassis out of the head box to fix the fuse holder after it got pushed inside. Did it onstage.


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## chuckharmonjr

I run a wet-dry mix between my two amps on stage but I have redundancy built into the snake wiring. The DSL is normally the dry primary amp while the 50 watt combo thru a 4x12 is the wet slap back. The DSL goes down, a quick twist of one knob and hit a switch in my pedalboard the 50 watter becomes the dry primary, so I can switch on the fly. That way I can hold out till break to find out what happened and work on it.


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## Adwex

Thread has been sticky'd.

Kudos to Martimus Maximus for sharing his vast knowledge and experience.


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## chuckharmonjr

Great move. It should have been stickied. Marty's presentation was excellent, very well stated and presented.


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## MartyStrat54

That's how you tell a pro from a novice. A pro will pack a lot more to a gig than just his axe and amp. He will take his "survival kit" with him as well. 

I've been lucky. I only had one tube failure on stage...but I was playing two identical amps (BF Bassman's). I turned the good amp up louder and then during the set break, I changed out the bad V1 tube. Yes, a V1 went out. Not a power tube. I had two complete sets with me. I was prepared for anything.

Chuck...you have a porta potty that you take with you on gigs?


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## Adwex

chuckharmonjr said:


> Great move. It should have been stickied. Marty's presentation was excellent, very well stated and presented.



I agree.


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## chuckharmonjr

MartyStrat54 said:


> That's how you tell a pro from a novice. A pro will pack a lot more to a gig than just his axe and amp. He will take his "survival kit" with him as well.
> 
> I've been lucky. I only had one tube failure on stage...but I was playing two identical amps (BF Bassman's). I turned the good amp up louder and then during the set break, I changed out the bad V1 tube. Yes, a V1 went out. Not a power tube. I had two complete sets with me. I was prepared for anything.
> 
> Chuck...you have a porta potty that you take with you on gigs?



Ex Cav Scout Officer Mr Air Force guy.....I am used to toting shit on my back and surviving with what I can carry....or what the helos can bring in....lol


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## jcmjmp

I have to say that I slightly dissagree with Marty with regards to power tubes not affecting tone that much. Just slap in a set of SED =C= EL34 and then compare them back to back with a set of Svetlana EL34s and you'lll see what I mean. 

Don't discount power tubes as being an important part of the tone and always ensure that they are properly biased and checked over every 6 to 12 months, more if you play a lot of gigs. 

Personally, I'm not too picky about tubes. As long as they are reliable and have the general tone I'm looking for, I'm happy.


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## Australian

jcmjmp said:


> I have to say that I slightly dissagree with Marty with regards to power tubes not affecting tone that much. Just slap in a set of SED =C= EL34 and then compare them back to back with a set of Svetlana EL34s and you'lll see what I mean.



This is true. I usually use =C='s for my amps, but have EH power tubes in my 205h and there was a difference in tone compared to the =C='s.


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## johnfv

Since so much of the discussion in the forums is focused on NOS tubes, I particularly liked the discussion here of some of the better CP tubes. Well done Marty


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## sccloser

Our old drummer used to think I was silly bringing a "survival kit" to gigs. He said I worried too much. I told him no, I was not worrying. I was being prepared. I'd worry without the kit!

Other than the other guitar player, everyone else in the band thinks I'm obsessed with "tubes." All I did was buy a bias probe so I could check and set my own bias, and swapped some tubes around. I also found some very reasonably priced NOS tubes and started rolling them a little. I do not see the harm.

I was fortunate back in the 80's to have a lot of NOS 12ax7's available to me because my dad was a certified electronics tech. So I learned first hand from listening with my own ears that some of the older NOS tubes sounded better than much of the cp stuff available then.


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## MartyStrat54

Well the majority of what I posted was regarding preamp tubes. However, I did sort of state exactly what JCMJMP brought up. I said that if you use thin sounding, cheap power tubes, your sound will suffer regardless of your volume level.

Power tubes will make some tonal difference, but V1 of the preamp will have the most impact on tone.


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## yladrd61

MartyStrat54 said:


> That's how you tell a pro from a novice. A pro will pack a lot more to a gig than just his axe and amp. He will take his "survival kit" with him as well.
> 
> I've been lucky. I only had one tube failure on stage...but I was playing two identical amps (BF Bassman's). I turned the good amp up louder and then during the set break, I changed out the bad V1 tube. Yes, a V1 went out. Not a power tube. I had two complete sets with me. I was prepared for anything.
> 
> Chuck...you have a porta potty that you take with you on gigs?



CP JJ ECC83s work very well in a BF Bassman as long as you have the correct spec 12AT7 in the PI slot I like NOS in the PI on those amps. However in my tweed LTD '59 RI Bassman i am Running an NOS Sylvania 12AY7 in V1, NOS '70s GE 12AX7 in V2, and a very nice late '50s National Labeled Tung Sol 5751 in the V3 PI, I am also running a set of mint GE 7581A's in the Power Tube slots and an NOS Sylvania GZ34 Rectifier tube. I also went back to the original tone stack and removed a .022 Preamp Filtering Cap. And took out the bright cap. With vintage style single coils I am able to plug into the Treble 1 channel and get a great tone. The biggest help was putting the 12AY7 in V1 and changing the caps and resistor in the tone stack like the original circuit 250pf treble cap, .022 mid-bass caps and 56K slope resistor, and reducing preamp filtering from .044 to .022 pf oh yeah and the NOS Rectifier dropped my plate voltage 20 VDC but it was a lot more stable than the Chinese Ruby when you crank it up !!! I will need t write another book to tell you about what I went through to get my '70 Metal Face Super Lead sorted out. If only I could find a CP EL34 that can take 500+ on the screens


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## 66 galaxie

This is a great article Marty. Very informative and well written.
Thank you for taking the time to post.


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## chadjwil

Marty, great thread...very informative. I would love to see you post some info about data sheets...what all those greek symbols mean and how to use that info to make informed decisions. I know that a lot of the techs and engineering types know what those symbols mean, but for the regular joe that info could be very usefull...not to mention maybe reducing some of the reliance (and your time and energy) on your personal knowlege. 

There are always gonna be those who don't know that a 12ax7 and an ECC83 are essentially the same thing (absolutely no offense intended to anyone...I only recently discovered these type things myself and I've been running tube amps for nearly 20 years...embarrassed!), hell I certainly don't know every manufacturers designation for similar dual triodes, but learning how to interpret the data sheets would be a great skill to have, I think.

Thanks for putting the time and effort in Marty!


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## hbach

Great post! 
Marty, is there a difference when testing or "rolling" tubes with a NMV amp where the idea is power amp distortion?

I have a box full of tubes as I live in Ecuador and you just can't get them consistently here, so I get some everytime I travel. But I guess anywhere in the world it's a good idea.

Very important part of the survival kit. Take an emergency ration of grog!  I took my beer last gig, as I knew they were just gonna serve hard licor and I suck enough as is. 
Of course by that logic the kit should contain one of these:


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## MartyStrat54

yladrd61 said:


> I will need to write another book to tell you about what I went through to get my '70 Metal Face Super Lead sorted out. If only I could find a CP EL34 that can take 500+ on the screens



You can still get RFT EL34's and these will handle over 500 on the screens. They can be found on EBAY. The seller's name is Bryan Sanborn.


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## MartyStrat54

hbach said:


> Great post!
> Marty, is there a difference when testing or "rolling" tubes with a NMV amp where the idea is power amp distortion?



You should try the tubes at the volume you plan on using the amp at. NMV amps are more prone to delivering power tube distortion. The quality of the preamp tubes in a NMV amp is very important, especially V1.

It's hard to beat NOS Mullard 12AX7's and real Mullard EL34's in a NMV amp.


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## chuckharmonjr

Does he have a brother named CHase, Marty?


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## MartyStrat54

chuckharmonjr said:


> Does he have a brother named CHase, Marty?



He sure does. He sells tubes out of a three pound coffee can.


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## nedcronin

Thanks for posting this Marty, awesome information. Very good of you to take the time for us.


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## MartyStrat54

Thanks NED.


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## Australian

Marty I was wondering, do you know how the 'made in Australia' compare to the Blackburn Mullards? 
I just bought some NOS Mullard 12AX7's and am wondering if they are still a desirable tube?


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## MartyStrat54

Australian said:


> Marty I was wondering, do you know how the 'made in Australia' compare to the Blackburn Mullards?
> I just bought some NOS Mullard 12AX7's and am wondering if they are still a desirable tube?



Well a lot of tubes were made in various locations using the Mullard design and there is a difference in the way they sound. How much? Probably not a lot. I would say they should sound real close.

Tubes were made in Australia and there are several home brands that I see on the international EBAY listings. 

Personally, I do not have any experience with Australian tubes. Sorry.


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## Australian

I hope they are similar. I'll find out tomorrow when they arrive.


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## Moving Air

MartyStrat54 said:


> Well a lot of tubes were made in various locations using the Mullard design and there is a difference in the way they sound. How much? Probably not a lot. I would say they should sound real close.
> 
> Tubes were made in Australia and there are several home brands that I see on the international EBAY listings.
> 
> Personally, I do not have any experience with Australian tubes. Sorry.



I have heard it suggested that Australian valves work much better in a combo 

Great sticky, should be required reading prior to registering


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## Georgiatec

Thanks for this Marty. As ever, reading your posts is an education.


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## cylon185

Awesome post.
And thanks for your tubes service


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## Australian

Im going to try my NOS Mullard pre tubes in my 2203 today, that currently has JJ's. 
Would replacing only V1 be enough to produce a desirable result, or should I change all three pretubes?


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## alank950

Hi Marty you ever heard of these tubes.
*[FONT=Arial,Helvetica,Sans Serif][FONT=Arial,Helvetica,Sans Serif]ungsol Re-Issue KT120 Valve[/FONT][FONT=Arial,Helvetica,Sans Serif][FONT=Verdana,Arial,Helvetica,Sans Serif]


Here is a link to the Tubes [/FONT][/FONT][/FONT]*


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## alank950

I was going to replace the KT88,s in my Marshall Major with these.
KT120 TUBES

With a plate dissipation of 60 watts, the Tung-Sol KT120 is the most powerful tube iN the 6550/KT88/KT90 family. A pair of these tubes in push-pull configuration can deliver power levels of 150 Watts or more. When it's run in circuits designed for 6550/KT88/KT90 tubes, the KT120 resists being overdriven and reliably delivers peak power. 

The KT120 has a taller glass bottle, longer internal plate structure, and much larger control grid cooling fins than current production KT88 tubes. Because the KT120 draws 100-300 mA more filament current than a standard 6550/KT88, check with your amp manufacturer to ensure you have the additional filament headroom to power these tubes. This new production Tung-Sol tube is manufactured in Russia for New Sensor.  These tubes have been burned in, thoroughly tested at operating voltages on the AT1000, and premium matched for both current draw (mA) and transconductance (Gm). Learn more about our burn-in and testing process here. 

Price is for a single tube and includes burn-in and standard matching service. Tubes ship in Tung-Sol retail boxes.
*KT120 substitution notes

*The KT120 tube is one of the more exciting developments in new production vacuum tubes. Generally speaking it is a drop in replacement for 6550, KT88 and KT90 tubes, as long as the larger bottle fits in your chassis. This tube also draws more filament current (100-300 mA more per tube) than 6550/KT88/KT90 tubes do, so you need to be sure your power supply can handle the increased demand. 

Many people report improved bass response and increased output with KT120 tubes. The reason for this stronger response is obvious when you look at its test results. New production 6550 and KT88 tubes we test range from 90-140% of the expected value for mA and Gm. Under the exact same operating conditions (500v plate, 300v screen, -30.5v bias) the KT120 rarely tests lower than 125% and can test as high as 185%. (We reject KT120 tubes that test higher than 165%--at some point you have to say enough is enough!) 

Most fixed bias amps have enough range to dial KT120 tubes in to the recommended current draw for that amplifier, though some do not. Even if you are unable to bias the tube all the way down to the recommended current draw you can probably still use KT120 tubes. Youll just have to do a little math to be sure the tubes are running safely. Simply take the plate voltage and multiply it by the current measured in mA. For example, if your plate voltage is 500v and you are measuring 70 mA across a single tube then the math goes like this 500 x 0.070 = 35 Watts. Since this is a 60 watt dissipation tube and the rule of thumb is to run tubes at 65% of their maximum dissipation (60 x .65 = 39 Watts), 70 mA across a single tube in this case would be just fine even though the manual is likely to recommend 50 mA for a 6550 tube. 

If you have an autobias amplifier you will want tubes at the lower end of the spectrum of KT120 tubes.


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## MartyStrat54

Australian said:


> Im going to try my NOS Mullard pre tubes in my 2203 today, that currently has JJ's.
> Would replacing only V1 be enough to produce a desirable result, or should I change all three pretubes?



In the 2203, V1 will be the most noticeable.


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## MartyStrat54

alank950 said:


> Hi Marty you ever heard of these tubes.
> *[FONT=Arial,Helvetica,Sans Serif][FONT=Arial,Helvetica,Sans Serif]ungsol Re-Issue KT120 Valve[/FONT][FONT=Arial,Helvetica,Sans Serif][FONT=Verdana,Arial,Helvetica,Sans Serif]
> 
> 
> Here is a link to the Tubes [/FONT][/FONT][/FONT]*



Yes I have. You will need to check to see if your Major's PT has the necessary filament current available to power these tubes. Also, they will need to be biased like a KT88.


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## Australian

I tried it in V1, and its got its mojo back, at least in how it responds dynamically. 
I'm going to try one in the AFD100 V1. That will be interesting.


----------



## MartyStrat54

I'm glad you like it. I had a feeling that it would kick your amp in the pants.

Post up about the AFD results.


----------



## Moose Lewis

Excellent thread, Marty. I've gotten some great info reading your stuff in the past year (and a few sweet tubes from ya too).

I liked the part about the order of rolling preamp tubes starting with the V1 in particular. If there is 1 single tube in an amp that affects the direction of the response - V1 is it. Everything else seems to be subtle changes. V1 seems to be able to take an amp from clean and dry to fat and wet; and make a marked difference in the type of tone as well. I'm already itchin' for more V1 tubes to experiment with.

Oh... and I keep my spares in a padded camera bag with velcro partitions, pockets and a bit of spare foam. Gotta keep them little jewels safe.


----------



## MartyStrat54

Thanks MOOSE. It's been a pleasure. Yeah, take care of them babies. You never know when you will need them.

I've said this many times before, V1 is the most important tube in the amp as far as how the basic tone will be...and the balls.


----------



## Moose Lewis

Whoa... I just had an EL34 experience. A shee-it-tee one, lol.

I was swappin' tubes around in the Tweaker (can switch power tubes without biasing) and popped in an old set of Ruby EL34s and I suddenly lost bottom and the highs became brittle and plinky instead of singin' sweet. Switched 'em back and voila!

The Rubys have left the building. I might need to think about getting a tube tester.


----------



## Schafedog

Trying to figure out tubes for JVM 410h.I'm playing a 2011 LP deluxe and have a 1960a cab. The head I bought used and it was built in 08 .I'm sure the tubes are stock.Im playing a 2011 LP studio deluxe and am looking for sounds of April Wine, UFO,MSG,Scorps etc. Not using any pedals yet either. anybody offer a little help?I mean the head sounds good,but not exactly what I'm after yet.I guess the term I hear slot is muddy.


----------



## MartyStrat54

Well this really isn't the place for what you are asking. Could you take your questions over to the Preamp Tube Thread?

http://www.marshallforum.com/marshall-amps/3824-preamp-tubes-who-what-when-where-why-how.html


----------



## Schafedog

Sure,sorry bout that.


----------



## Lowlife

Hey Marty
Maybe you could add what the differences are between the 12AT7, 12AU7 and the 12AX7, and maybe what the different kinds are used for, in terms of preamp tubes.


----------



## MartyStrat54

The most common preamp tubes used in a guitar amp are the 12AX7(A), 5751, 12AT7, 12AY7 and 12AU7(A).

The gain (MU) factor is as follows:
12AX7/ECC83-100mu
5751-70mu
12AT7/ECC81-60mu
12AY7-45mu
12AV7-41mu
12AU7/ECC82-20mu

The 12AX7 and 5751 are very similar in construction and operation. I like my high gain amps to use a 12AX7 in the V1 slot. However, some people like to "smooth out" the initial gain of V1 and will use a 5751. The 5751 is a very good sounding tube with very low microphonics. 

The 12AT7, 12AY7 and 12AU7 are considered as "cousins" to the 12AX7. Their design and operation are different over the 12AX7, but will still work in the 12AX7 circuit.

To me, a 12AT7 is not a very musical sounding tube. It is brighter sounding and has less bass. Some amps like Fender, uses them in the phase inverter. However, if my amp comes from the factory with a 12AX7 in the PI, that is what I use. 

If someone puts a 12AY7 in V1 and a 12AT7 in the PI, the amp is going to sound neutered. If this is the sound they prefer, then they need to look at getting a different amp. 

I don't think a 12AU7 has any place in a Marshall, but some people will call me wrong. Running one of these in V1 or the PI is not a good idea. If you like how this sounds, then maybe a solid state amp is in your future.

Of course, as stated earlier, there are other factors to consider than just the gain factor of the tube. Plate resistance (Rp) and plate dissipation are two of the more important ones.

Several years ago, we did extensive testing of the 12BZ7 in high gain Marshall amps. The rumor was the 12BZ7 was a real animal in V1. In truth, the 12BZ7 was a horrible tube in V1 and I would not recommend spending the money to try one.


----------



## solarburn

> If someone puts a 12AY7 in V1 and a 12AT7 in the PI, the amp is going to sound neutered. If this is the sound they prefer, then they need to look at getting a different amp.



Customer walks into music store to buy an amp:

Excuse me but I'm looking for an amp that uses a 12AY7 in V1 and an AT7 in the PI. I'm looking for that "special" kind of tone and feel...

Of course sir. Right this way. Here in the "nutless" section we have "Ball-less amps". Take your time sir and play as loud as you like. I'm sure no one will notice...I mean mind.


----------



## Buggs.Crosby

Marty...just out of curiosity what is the gain factor of a 12BZ7


----------



## MartyStrat54

Buggs-It has a gain factor of 100. The same as a 12AX7. However, it has half the plate resistance of a 12AX7.

12BZ7
Plate Voltage-300V
Plate Dissipation-1.5W
Plate Resistance-31.8K Ohms
Transconductance-3200mhos
Plate Current-2.5mA

12AX7
Plate Voltage-330V
Plate Dissipation-1.2W
Plate Resistance-62.5K Ohms
Transconductance-1600mhos
Plate Current-1.2mA


----------



## Marshall Mann

Hey guys, just FYI

I posted in the Preamp tubes thread, but didn't get allot of response. So Just in case anyone else encounters these....

I recently bought a mixed bag of tubes and came across a 12bh7 and a 6bu7. They look like a taller 12ax7 (9 pin on steroids). I read that the BH7 was interchangeable with a 12au7, but was I not sure. This is what I heard back from Brian at Tube Depot.



A 12BH7 is interchangeable with a 12AU7, but not a 12AX7. Here is a link to specs for a 12BH7:
NJ7P Tube Database Search
A 6GU7 is not interchangeable with 12AX7 or 12AU7: NJ7P Tube Database Search
Here is a link showing gain factors for 12AX7 substitutions...any of these tubes listed will work fine as 12AX7 replacements, as long as you are using a lower gain substitute:
Preamp Tube Gain Factors


----------



## SyncreticGuitar

Thanks for this great info Marty! I've been pouring over this thread for days and have made real progress in modifying the sound of my DSL100.


----------



## MartyStrat54

Come on over and join us at the Preamp Tube Thread.


----------



## sccloser

Marty, How about the infamous 12AV7? I've got one sitting here on my desk, NOS Sylvania in box.

What in the world could I use that for?


----------



## MartyStrat54

Up there in my chart it shows the AV7 as having 41mu of gain. It's not much use in most tube guitar amps. There again, someone might run one in V1 on an older Fender amp. Try selling it and using the money to buy a used NOS 12AX7.


----------



## big dooley

MartyStrat54 said:


> I don't think a 12AU7 has any place in a Marshall, but some people will call me wrong. Running one of these in V1 or the PI is not a good idea. If you like how this sounds, then maybe a solid state amp is in your future.



no not in the gain stages or the PI... however, they seem to be a great option in an AC coupled cathode follower circuit, meant as send buffer for an effects loop... someone over at the JVMforum has put a 12au7 in V3 and reported good results, as he didn't have signalloss anymore with the loop set at 100% wet


----------



## Wycked Lester

marty, i just noticed in your sig,....that it looks like ya put a hot rail in the middle of that strat [remember, i got the maple neck brother] I've never done that before, how does it sound?


----------



## MartyStrat54

Wycked Lester said:


> marty, i just noticed in your sig,....that it looks like ya put a hot rail in the middle of that strat [remember, i got the maple neck brother] I've never done that before, how does it sound?



Sent you a PM.


----------



## ckr1231

I read somewhere that the Phase Inverter is the hardest working tube in an amp and should balanced accordingly with the power tubes.
Is there any truth to this ? 
Is this just more corporate buisiness garbage to sell higher priced tubes ect ?


----------



## MartyStrat54

The phase inverter does not need to be perfectly balanced. Some people use a 12DW7 as a PI tube. This is highly lopsided at 100/17mu. I personally prefer somewhat lopsided high gain tubes for my PI.


----------



## MartyStrat54

big dooley said:


> no not in the gain stages or the PI... however, they seem to be a great option in an AC coupled cathode follower circuit, meant as send buffer for an effects loop... someone over at the JVMforum has put a 12au7 in V3 and reported good results, as he didn't have signalloss anymore with the loop set at 100% wet



And this is why I stated some people will call me wrong. Everybody is different and they will try different tubes in their amp. If the guy with the JVM likes a 12AU7 in V3, I can't argue with him.


----------



## sccloser

big dooley said:


> no not in the gain stages or the PI... however, they seem to be a great option in an AC coupled cathode follower circuit, meant as send buffer for an effects loop... someone over at the JVMforum has put a 12au7 in V3 and reported good results, as he didn't have signalloss anymore with the loop set at 100% wet



I got two NOS JAN Philips 6189W (12au7) that I would be willing to sell or trade.


----------



## big dooley

MartyStrat54 said:


> And this is why I stated some people will call me wrong. Everybody is different and they will try different tubes in their amp. If the guy with the JVM likes a 12AU7 in V3, I can't argue with him.



well, the DC coupled cathode follower (V3A) would be better off with a 12ax7 in there, but that is personal preference... 
for effectsloop send buffers (V3B in the JVM)a 12au7 seems to be a better choice from a technical point of view...
but this would mean you need a reversed triode 12DW7 like JJ makes on request... also known as the ecc823 (ecc832 is the regular name)


----------



## MartyStrat54

Thanks Dooley. I've heard of that special order JJ. I have one amp that only uses one half of the extra 12AX7 that was installed. Seems sort of a waste of a good tube.

http://www.jj-electronic.sk/pdf/ECC 832.pdf


----------



## RiverRatt

sccloser said:


> I got two NOS JAN Philips 6189W (12au7) that I would be willing to sell or trade.



Don't we all  I probably have a couple dozen or so 12AU7's, maybe more than that. I tried to sell eight NOS NIB military 6189's for $15 on eBay and didn't get a bid.

I will say that I noticed the least difference in tone by using a lower gain tube in V3 on my DSL50 than any other socket.


----------



## big dooley

MartyStrat54 said:


> Thanks Dooley. I've heard of that special order JJ. I have one amp that only uses one half of the extra 12AX7 that was installed. Seems sort of a waste of a good tube.
> 
> http://www.jj-electronic.sk/pdf/ECC 832.pdf



they were a hot item over at the JVMforum for people who wanted to tame down the OD orange and red modes without affecting all the other modes... this is the only tube that would do it, but they are very hard to get, so after a while the idea faded away and people changed the plate resistors of that perticular gain stage to a lower value (from 200K to 100K), which did more or less the same


----------



## MartyStrat54

If you have a tube question, please feel free to come over to the Preamp Tube thread or if it is power related, the Power Tube thread. I feel you can get some solid info if you try us first.


----------



## MartyStrat54

Any questions or comments?


----------



## diesect20022000

any word on the circuit for the lil night train? I'd like to get some tubes for it through ya Marty


next i plan on getting a couple of RCA's for my Dragon and the triamp.


----------



## MartyStrat54

I had to edit this post as I was thinking of the wrong mini amp. How many pre's are in the mini NT?


----------



## brp

Actually the *LIL'* Night Train has 2 12AX7 for the preamp and a single 12AU7 for the power tube.

The original "NT15" uses 2 12AX7 for pre and 2 EL84 for power.


----------



## MartyStrat54

The preamp uses two 12AX7 tubes, while the power-amp uses one 12AU7. 

NOS 12AU7's are really inexpensive. You could get a nice black plate on EBAY for cheap.

I would probably start out with a long plate Mullard to see what that would do. I'm assuming that the other 12ax7 is the PI?


----------



## MartyStrat54

brp-Yes, I was thinking of your Blackheart amp.


----------



## MartyStrat54

Well I can't find out what the other 12AX7 does.


----------



## brp

MartyStrat54 said:


> brp-Yes, I was thinking of your Blackheart amp.




I thought that might be the case. 

Which I want to get your thoughts on as to which NOS 12ax7's would be a good choice for the pre and power of said Blackheart but that's a discussion for elsewhere I guess.


----------



## brp

MartyStrat54 said:


> I'm assuming that the other 12ax7 is the PI?



Well it is in the 15 watt version, according to Joe/solar...


----------



## solarburn

brp said:


> Well it is in the 15 watt version, according to Joe/solar...



Yep.


----------



## Axeologist

MartyStrat54 said:


> The most common preamp tubes used in a guitar amp are the 12AX7(A), 5751, 12AT7, 12AY7 and 12AU7(A).
> 
> The gain (MU) factor is as follows:
> 12AX7/ECC83-100mu
> 5751-70mu
> 12AT7/ECC81-60mu
> 12AY7-45mu
> 12AV7-41mu
> 12AU7/ECC82-20mu
> 
> The 12AX7 and 5751 are very similar in construction and operation. I like my high gain amps to use a 12AX7 in the V1 slot. However, some people like to "smooth out" the initial gain of V1 and will use a 5751. The 5751 is a very good sounding tube with very low microphonics.
> 
> The 12AT7, 12AY7 and 12AU7 are considered as "cousins" to the 12AX7. Their design and operation are different over the 12AX7, but will still work in the 12AX7 circuit.
> 
> To me, a 12AT7 is not a very musical sounding tube. It is brighter sounding and has less bass. Some amps like Fender, uses them in the phase inverter. However, if my amp comes from the factory with a 12AX7 in the PI, that is what I use.
> 
> If someone puts a 12AY7 in V1 and a 12AT7 in the PI, the amp is going to sound neutered. If this is the sound they prefer, then they need to look at getting a different amp.
> 
> I don't think a 12AU7 has any place in a Marshall, but some people will call me wrong. Running one of these in V1 or the PI is not a good idea. If you like how this sounds, then maybe a solid state amp is in your future.
> 
> Of course, as stated earlier, there are other factors to consider than just the gain factor of the tube. Plate resistance (Rp) and plate dissipation are two of the more important ones.
> 
> Several years ago, we did extensive testing of the 12BZ7 in high gain Marshall amps. The rumor was the 12BZ7 was a real animal in V1. In truth, the 12BZ7 was a horrible tube in V1 and I would not recommend spending the money to try one.



So where does the 7025 fit in. I have used these in V1 because they are quiet. Are they anything like the ECC83?

Great thread!


----------



## MartyStrat54

The 7025 was introduced I believe in 1952 by RCA. This is the low noise, "industrial" version of the 12AX7. This has a spiral wound filament which reduces hum and noise. These are usually the best choice for demanding hi-fi applications and were found in the first gain stage of almost all early 50's to 60's hi-fi amps. However, tube manufacturing became so good that many 12AX7A's which also had the spiral wound heater filaments, were labeled with 7025 on the glass. Most premium brands of 12AX7A's/ECC83's (such as a Philips made tube) and Black Plate (such as RCA and Raytheon) types also have very low noise. A 7025 has the same average gain as a 12AX7. That is, a gain factor of 100.

I used to be very heavy on 7025's in V1. This was when I was running my amp in the clean channel only and using a DigiTech FX pedal. I still recommend them for those who are looking for the best cleans out of their amps.

FYI-There are several current production CP 7025 tubes for sale. These do not perform like a NOS RCA or GE 7025. The best CP 7025 is the "Preferred Series" sold by the Tube Store.


----------



## solarburn

Axeologist said:


> So where does the 7025 fit in. I have used these in V1 because they are quiet. Are they anything like the ECC83?
> 
> Great thread!



It is an ECC83/12AX7. 2 names for the same tube. ECC83 is the European designation for a 12AX7. 7025 is a kind of 12AX7/ECC83.


----------



## Axeologist

FYI-There are several current production CP 7025 tubes for sale. These do not perform like a NOS RCA or GE 7025. The best CP 7025 is the "Preferred Series" sold by the Tube Store.[/quote said:


> That's for sure... I just pulled a T.A.D. 7025 out of my Jubilee (V1) and replaced it with a GT 12AT7 (I was out of Tung-sol's) which I didn't think I would like but WOW it killed... or at least it did after listening to that 7025 for an hour.
> 
> I will go with Preferred Series from now on.


----------



## MartyStrat54

Well remember, you can always shop around on EBAY and get a real RCA 7025 for a fair price. Just pay attention to whether the seller lists the tube test results. Try to buy a tube that has the greatest margin from the lowest acceptable reading. For instance, if the lowest acceptable reading is 1250 and the tube listed has tested at 2100, this is a very good tube as far as conductance and emissions.


----------



## Sebat

thanks for the info Marty!


----------



## MartyStrat54

A lot of people ask me why current production tubes can't be as good as vintage NOS. It boils down to three main points.

1.Type of coatings used.
2.Type of vacuum pulled.
3.Quality of the parts used.

The coatings used by CP tube manufacturers are not of the same formula as what was used by the majority of the tube makers in the heyday of tube production. The old coatings were very toxic and thus, the newer coatings are more environmentally friendly. The old coatings were better however and this allowed them to last longer. Some preamp tubes were rated for 10,000 hours of life. This was due to the coatings.

The type of vacuum pulled on a CP tube is nothing like what was pulled on a NOS tube. The vintage manufacturers did everything they could to get the best vacuum pulled. Again, the better the vacuum, the longer a tube would last and the stronger it would be. Nowadays, a tube gets a quickie vacuum. The whole line of thought is if the tube fails, you just replace it with another tube.

I've posted on the tube threads about all the materials that were used to make a vintage tube. All of the minute parts were very meticulously produced. Some of the tolerances were within one hundred thousandth of an inch and this was back in the late 30's. It only got better by the 50's. The parts used in tubes today are passable, but they don't stack up to yesterday's tube standards.


----------



## cylon185

Best explanation ever!


----------



## MM54

On the topic, an comparison between NOS and CP that's quite nice and physical, can be found here: http://www.marshallforum.com/marsha...-reissue-vs-original-physical-comparison.html


----------



## MartyStrat54

Yes that was nicely done and I thank you for linking it over here. Your experiment shows that sometimes there is more to a tube than some "bought" trademark name.

A Mullard isn't a Mullard unless it's an original NOS Mullard.


----------



## HAMPAMP TUBE AMP SERVICES

Great thread Marty, I've got close to a hundred or so used old stock 12AX7's that I use to verify how sick some of these newer amps sound with CP's (kind of ashamed to admit that I hord the NOS for my self), even the used old stock that check weak on the tester seem to have superior tone than the bulk of the CP's even though they may not have the punch. 80% of 12AX7's that I pull from old equipment are still very strong and non-microphonic and after side-by-side comparison, most of my customers will go with the used old stock, seems like the exception to the rule are the guys that play Metal, but I live out in the sticks where everyone wears overalls, has no teeth and can't see 2 feet in front of them so maybe we are tone-def too. Seems like the only old 12AX7's that don't seem to hold up are the ones I've striped from Japannese amp like for instance, Lafayette. They are maked "Made in Japan". Know anything about these?


----------



## MartyStrat54

Wow! Good to hear from you. It's been a while. I would expect someone like you to have a large stash of vintage glass. I've said more than once that I have had Fender users that actually preferred a worn out USA 12AX7 in V1. I've used RCA's in many Fender amps that tested at about 75 percent. The customer loved the tone of these tubes. 

Now as far as Japanese tubes, there are several brands and some of them were made back in the late 50's and are quite good. Others are not quite as good. The Matsushita comes in three distinct forms, the halo getter, slant halo getter and slant D getter. The slant versions are good with the D being the most desirable. The regular halo is just a marginal tube. NEC made some good tubes including the 12AD7 which is a very low nosie 12AX7 variant. Toshiba was another common brand.

What brands of Japanese tubes do you have?

It is amazing how old some Japanese tubes are. They got set up and were going strong by the mid to late 50's thanks to all of the US TV/Radio manufacturers.


----------



## HAMPAMP TUBE AMP SERVICES

Nice to hear from you Marty, not sure what brand, they just have 12AX7 made in japan on them, if there were any other markings, they have been rubbed off. I did have a nice Lafayette 75 amp in the shop a couple of weeks ago that sounded great (after a cap job), it had a couple of MIJ 12AX7's, 1 6AU6 and a couple of 7198's; oh and a 6CA4, but the MIJ's that I stripped out of amp's just weren't much good. Maybe they were just tired. maybe I AM tone-def.


----------



## fstrat59slp

Marty I would like to thank you for all the great info. The guy who owned my dsl previously had the preamp tubes lined up to what you had described in the original post. However do you think I should by all new tubes preamp and power amp just to be safe? It has the el34 elecro harmonix in the pt section and like you described in the preamp section. I think I'm going to take it to a tech sometime soon to get it properly biased, but in the meantime should I order new tubes just to start fresh, and so I'll know what's up with the amp.


----------



## MartyStrat54

Whenever I get a used amp. I always install a new set of tubes. That way I know what I have in the amp.

I really like the EH 6CA7 power tubes in the DSL/TSL. Also, the DSL really likes a good NOS tube in V1. You can get one on EBAY for $20. Try and get a GE if you can.


----------



## fstrat59slp

Thanks for the help Marty. I'm gonna try and order a set soon so I can get this head back up and running. Going to buy a multimeter tomorrow thanks again for all the help.


----------



## Drewser141

I would also like to thank Marty for his knowledge on all things tube. My wife however might not be so thankful because I now have a big box full of tubes of various type and description which means I had to get a tube tester(ya gotta know what ya got, right?). I also now have a SEL amp project started which means more diag. equipment (I don't really need an Oscope but they look so cool) and more time in the workshop...maybe she's thankful after all. Anyways, thanks for the new obsession.


----------



## MartyStrat54




----------



## MartyStrat54

http://htmlimg2.scribdassets.com/9deefg1im8nmcl7/images/73-d893010583.jpg

http://htmlimg3.scribdassets.com/9deefg1im8nmcl7/images/78-ef8f5e2d00.jpg


----------



## tresmarshallz

Hi, I posted this pwr tube question in another section and it didn't get any responses, so thought I would try here. Maybe it is just a dumb question though 

_Someone just gave me two quads of early 90's Marshall labeled EL34M tubes. I am so psyched! One set is really fresh and only has a year or so of use on them. The other set has probably 8+ years of use on them.

I think these are great quality tubes from Tesla, right? How do these compare with current production powertubes like JJ's? Do these tubes last longer than CP pwr tubes, wonderin if the set with 8yrs useage on them would still have any life left in them....

thanks

Drew _


----------



## MartyStrat54

They could be Tesla's or RFT's. There's no telling what shape the used set is in. It would take a good tube tester to determine that. There is a good chance that they are still good. I sold a Peavey Mace amp from 1978 a year ago with the original power tubes in it. They all tested very close at 87-88. 

The tubes should outlast any current production power tube if they are indeed Teslas's or RFT's.


----------



## tresmarshallz

Thanks Marty, since I don't have a tester and wouldn't know how to use one if I did  , I'll just fire them up in an amp and see what they do, maybe I'll get lucky. I did put the fresh set of the el34M's in my 800 and it sounds better than ever for sure. 

Getting rid of the JMP to SolarBurn must have been a tough decision to let it go, but at least you know it's going to a good home  and I guess the 800 you still have gives you all you need to cover that era of rocking tone.


----------



## MartyStrat54

Joe deserved a solid amp from a reputable source. I've known him for over three years now. Yes, it was a hard decision, but Joe will give it a good home. It is a player's JMP as it has a state of the art Steve Miller FX loop and has a voicing mod by Wilder. All new caps and cleaned up. It's good to go for another 15 years.


----------



## tresmarshallz

I just found a pic from an old thread where RiverRatt posted a pic of some 90's Tesla's and mine matched perfectly, with the stapled plates and no dimple in top, I am 100% sure what I have are Tesla's. I have two matched quads and also a pair of them that came in SLX stock, I am happy to have these knowing they will likely outlive any CP tubes I would buy.
Thanks RR


----------



## meballar

Marty,
I was servicing my Jube last night and freaked out that it had Philips Miniwatt EL34s! I looked at ebay and those things are just insanely expensive. I would like to buy a quad of current production tubes. Do you mind to rank them in your opinion? I see many different manufacturers. Are there any brands I should steer away from? Thanks.
Mike


----------



## Ampcrazy

I put new preamp valves in my JCM800 combo, 50W 4010, so i had 3 EH gold pin 12AX7's, but i don't know it seemed noisier than before when i crank the preamp all the way up for low volume practice at home. I substituted a 12AY7 in V1 and it seems better, not as much noise. Has anyone else tried this?


----------



## zenfly

Ampcrazy said:


> I put new preamp valves in my JCM800 combo, 50W 4010, so i had 3 EH gold pin 12AX7's, but i don't know it seemed noisier than before when i crank the preamp all the way up for low volume practice at home. I substituted a 12AY7 in V1 and it seems better, not as much noise. Has anyone else tried this?



Yes.. you might try a 5751 that also does this. I like the NOS JAN (joint army navy).. 12au7 even less gain..12at7 also but they are not good tone generators..


----------



## Ampcrazy

zenfly said:


> Yes.. you might try a 5751 that also does this. I like the NOS JAN (joint army navy).. 12au7 even less gain..12at7 also but they are not good tone generators..


Thanks zenfly, yeah originally it had ECC83's and they were good, fairly quiet, but on putting in a new EH12AX7 gold tip in the V1 position it was really noisy, much more noisy than before. I just wish there were good current production 12AX7's that weren't as noisy as they are. I couldn't afford NOS tubes, though i wish i could!


----------



## Roadburn

Question of questions...


The numbers on the packages or labels on tubes, can they give an indication of any sort?
More/less headroom, longer/shorte life-time etc.???
Could even be that there is no correlation at all.

I have 3 EL84's with totally different numbers, not even close.

Sovtek EL84M - 18 (on the box)
"Marshall" JJ EL84 - 30 (on a "JJ" label)
JJ EL84 - 43.6 (on the box)

The Sovtek has ~25% noticable more headroom then the other 2
Not much difference between the 2 JJ's


Would be handy to know what the local shop tries to shove into my hands.


----------



## GIBSON67

Ampcrazy said:


> Thanks zenfly, yeah originally it had ECC83's and they were good, fairly quiet, but on putting in a new EH12AX7 gold tip in the V1 position it was really noisy, much more noisy than before. I just wish there were good current production 12AX7's that weren't as noisy as they are. I couldn't afford NOS tubes, though i wish i could!



I've found that you don't have to go NOS when you buy preamp tubes. And prices on EBAY are not really higher for OS tubes compared to CP tubes. And out of the dozens I've bought only 2 have not been good and I've gotten money back for those. Preamp tubes last for a really long time unlike power tubes.

I now have 8-10 Mullards, all under $25 each
Amperex under $20 each
Sylvanias, GEs and RCAs under $15 each


You can find good deals if you are patient.


----------



## Ampcrazy

Roadburn said:


> Would be handy to know what the local shop tries to shove into my hands.


Yeah i was reading an amp book and the author suggested going out and buying a bunch of preamp tubes and sorting through them to weed out the one's you like from the others. Problem is who's got that kind of disposable income to spend on a hit or miss? i just wish you knew for certain that when you got new tubes they were gonna be up to a certain standard


----------



## Roadburn

Roadburn said:


> Question of questions...
> 
> 
> The numbers on the packages or labels on tubes, can they give an indication of any sort?
> More/less headroom, longer/shorte life-time etc.???
> Could even be that there is no correlation at all.
> 
> I have 3 EL84's with totally different numbers, not even close.
> 
> Sovtek EL84M - 18 (on the box)
> "Marshall" JJ EL84 - 30 (on a "JJ" label)
> JJ EL84 - 43.6 (on the box)
> 
> The Sovtek has ~25% noticable more headroom then the other 2
> Not much difference between the 2 JJ's
> 
> 
> Would be handy to know what the local shop tries to shove into my hands.




So, did I ask a stupid, forbidden or secret question? Or maybe even all 3..?



Update: So I found out that the only use those ratings have is to find matching tubes of the same brand AND type.
Different brands but the same types doesn't work because manufacturers might use different measuring equipment.
And then there are the traders, who sometimes measure tubes personally (NOS tube traders for instance)

It makes sense now that those numbers don't make any sense without knowing what kind of tubetester is used and what kind of test is done.


----------



## silverface

Even those ratings/classification numbers/whatever within a particular manufacturer's tubes means only that they are loosely "matched" according to whatever method that manufacturer (actually reseller - there are VERY few direct-sales manufacturers of tubes) thinks is best.

FWIW it's almost impossible to match power tubes yourself without specialized tools (and usually an amp to use them with) - "tube testers" 1) generally don't hit tubes with nearly the plate voltage a guitar amp provides, and 2) most tube testers you find on the internet need calibration - and expensive and hard-to-find service. My method, which many other techs use, is to use a transconductance-type tube tester to do preliminary checks; then plug the tubes into a well-serviced amp and use a tool like an Allesandro Bias and Matching Meter (my choice), a Weber Bias meter or any similar unit (or a properly-wired tube base and a multimeter).

That only works for Octal-based power tubes.

But matching is, IMO, sometimes a bit over- stressed. You can easily be mismatched with bias readings +/- 5ma with EL34's or 6L6's and the amp will sound just fine - it's a matter of finding the bias "sweet spot" that works for your playing and rig (and volume level) and still keeps the tubes in the "safe zone".

And as noted above with perfectly;y-balanced phase inverters, perfectly-matched tube sets can sound a bit "stiff". I'll sometimes intentionally use tubes that are off by 10ma or so and crank the amp for a session, getting a "raw" sound that sounds very aggressive. I would not run it that way for a 4-hour gig though.

+1 on carrying backup tubes (and a backup amp).

Too many newbie tube amp buyers think the things are "plug 'n play" like solid state amps - "Whoopee, I bought a Bluesbreaker reissue, now I'll sound great!"...only to open the shipping container, plug it in - and their tone sucks.

That's because almost ALL manufacturers bias amps cold from the factory - it's a choice between "mostly cold" and not having tubes blow up or "mostly hot" and having tubes...and possibly other components...blow.

So they DO NOT ship them to sellers "dialed in" for sound - because a tube amp needs to be dialed-in for YOUR sound, which is the point of this thread - you have to play with the preamp tubes, work with power tube bias, and learn how the things work.

And you need to carry spares. Every experienced guitarist I know carries a backup amp to EVERY gig, and has a road case with spare tubes, fuses, cables, a few backup pedals, soldering equipment, tools, strings tuner etc etc.

If you want "newbie" stamped on your forehead show up to a jam and ask someone if you can borrow a cord. Or a strap. But seriously, the same goes for tubes. Blow something during a set and if you are prepared, you immediately hook up your backup amp - then during a break try to figure out what happened.

Be prepared. Tubes are MUCH cheaper than cancelled gigs.


----------



## blueprodigy

Just a quick question:

Your post recommends buying a Tung Sol. I've recently read NOT to use the Tung Sol in a Marshall with a cathode follower circuit (???). I have a JCM2000 and wanted to pop in a high-gain pre-amp tube in V1, and the Tung Sol RI comes highly recommended, but I'm pretty certain my JCM2000 DSL (to be more specific) has the cathode follower circuit (again, ????). I've ordered teh dual EH's for V3/4, now I'm ready to get V1/2 up and running.

Is this fact or fiction in regards to the Tung Sols? I'm trying to get close to an 80's metal+ sound out of the amp. Currently it's stocked with Marshall branded pre's and power tubes.

Thanks!


----------



## solarburn

blueprodigy said:


> Just a quick question:
> 
> Your post recommends buying a Tung Sol. I've recently read NOT to use the Tung Sol in a Marshall with a cathode follower circuit (???). I have a JCM2000 and wanted to pop in a high-gain pre-amp tube in V1, and the Tung Sol RI comes highly recommended, but I'm pretty certain my JCM2000 DSL (to be more specific) has the cathode follower circuit (again, ????). I've ordered teh dual EH's for V3/4, now I'm ready to get V1/2 up and running.
> 
> Is this fact or fiction in regards to the Tung Sols? I'm trying to get close to an 80's metal+ sound out of the amp. Currently it's stocked with Marshall branded pre's and power tubes.
> 
> Thanks!



V3 is your cathode follower in the 50/100 watters.


----------



## blueprodigy

Thanks!

I understand the V3 is the cathode follower (that means V4 is the PI, correct?).

Are you saying do NOT use the Tung-Sol in the V3 slot, but it's ok for V1/V2? Like I mentioned, and maybe I mis-read, some have said not to use the Tung-Sol at ALL in the JCM2000, but you're saying (by assumption) not to use it in the V3...correct?

I have the new EH's in V3/4 now.


----------



## solarburn

blueprodigy said:


> Thanks!
> 
> I understand the V3 is the cathode follower (that means V4 is the PI, correct?).
> 
> Are you saying do NOT use the Tung-Sol in the V3 slot, but it's ok for V1/V2? Like I mentioned, and maybe I mis-read, some have said not to use the Tung-Sol at ALL in the JCM2000, but you're saying (by assumption) not to use it in the V3...correct?
> 
> I have the new EH's in V3/4 now.



Use it in V1 or V2. Not in the cathode follower. Yes V4 is the PI. I thought it sounded good in V1.


----------



## blueprodigy

Thanks again!

That's the direction i'm heading. Tung-Sol in V1, JJ ECC83S in V2. The EH's in 3 and 4 made a noticable difference. Of course, now that good tubes (EH) are mixed with the Marshall stock chinese tubes (Shunguang???), my guitar is a bit more microphonic...lol. BUT, here's hoping the Tung-Sol remedies that.

Lucked out with the Marshall stock power tubes: all Svets.


----------



## JAC

Nice thread Marty, thanks! I noticed that I like the way JJ Electronics ECC83s sound better in my Fender VC than the JJ ECC803s. The ECC83s seem to be more alive. I can hear my speaker sounding more alive. It has more punch and has more dirt, bite and definition. I feel the ECC803s are probably better where there might be too much gain perhaps. I know this is a small 6 watt amp but, when I cranked it a bit I could notice these differences. I also have a question about some old preamp tubes I have but, I don't know if this is the right place to ask about them.


----------



## zenfly

This should be read by anyone with tube questions before posting and the link should be attached as post #2 when 99% of questions are asked.. This here my friends is required reading for anyone with a tube amp.. 

Marty...YOU DA' MAN


----------



## Heritage Softail

Awesome thread!

I have a power tube question. 

My DSL 100 has EL34 winged C tubes in it. Are E34L tubes a proper replacemment? If so, is there a tube rating to fit best?

I am hesitant to ask this of the guys at the Guitar Center.

Thx.


----------



## mickeydg5

Heritage Softail said:


> Awesome thread!
> 
> I have a power tube question.
> 
> My DSL 100 has EL34 winged C tubes in it. Are E34L tubes a proper replacemment? If so, is there a tube rating to fit best?
> 
> I am hesitant to ask this of the guys at the Guitar Center.
> 
> Thx.


 

Yeah, I would not trust a sales person or clerk at a chain store.
First find a technician you like who can test your old tubes. Replace if need be. It is always best to check amplifier and supply voltages to calculate proper bias. You cannot always trust quoted tube ratings.

And yes, E34L are direct replacement for EL34.


----------



## Heritage Softail

I try and not be critical of people. He salesgirl at GC was telling me she is all about Marshall. They have this awesome new amp, a JMC 901. I should seriously consider trading in. She asked what I was playing. I told her an old Mesa MKIIC. She said I could upgrade to a newer amp and get 15% off. 

I asked for some 6L6 power tubes, and asked for yellow code tubes. She said they only had clear glass tubes, no colored tubes. I said, that seems racist.. She looked genuinely confused... 

Another typical trip to guitar center. She did have a nice tight t-shirt and a nice rack.


----------



## JTyson

Heritage Softail said:


> I try and not be critical of people. He salesgirl at GC was telling me she is all about Marshall. They have this awesome new amp, a JMC 901. I should seriously consider trading in. She asked what I was playing. I told her an old Mesa MKIIC. She said I could upgrade to a newer amp and get 15% off.
> 
> I asked for some 6L6 power tubes, and asked for yellow code tubes. She said they only had clear glass tubes, no colored tubes. I said, that seems racist.. She looked genuinely confused...
> 
> Another typical trip to guitar center. She did have a nice tight t-shirt and a nice rack.




wassup brudda!


----------



## VAGINAGAS

My thread with tube questions isn't getting any response. So, I'll try here. I have a JCM 2000 TSL. It needs new power tubes. I can bias so that isn't an issue. I am just overwhelmed with too many decisions. There are so many brands out there I don't know what decision to make. I figure I'll just stick with EL34s, but what brand? My thinking is it's better to go with the high priced tubes, and I find out there made in China. Is that a bad thing? I wont buy my dog food if it's made in China. Others are made in Slovakia. There are Groove tubes, JJs, Electro Harmonix, on and on.

Also, what does head room mean?

As far as preamp tubes go, can I switch my tubes around any damn way I please? V1 is preamp tone and gain, but what to the others, V2 V3 and V4 do?


----------



## BluesDisciple

VAGINAGAS said:


> My thread with tube questions isn't getting any response. So, I'll try here. I have a JCM 2000 TSL. It needs new power tubes. I can bias so that isn't an issue. I am just overwhelmed with too many decisions. There are so many brands out there I don't know what decision to make. I figure I'll just stick with EL34s, but what brand? My thinking is it's better to go with the high priced tubes, and I find out there made in China. Is that a bad thing? I wont buy my dog food if it's made in China. Others are made in Slovakia. There are Groove tubes, JJs, Electro Harmonix, on and on.
> 
> Also, what does head room mean?
> 
> As far as preamp tubes go, can I switch my tubes around any damn way I please? V1 is preamp tone and gain, but what to the others, V2 V3 and V4 do?



I think you first need to define what you want out of the power tubes and preamp assortment. What kind of sound are you after? Then begin to search out sound samples, and note what kind of tubes are being used. Just a thought.


----------



## VAGINAGAS

BluesDisciple said:


> I think you first need to define what you want out of the power tubes and preamp assortment. What kind of sound are you after? Then begin to search out sound samples, and note what kind of tubes are being used. Just a thought.


 
Well, yea I was sent a link about preamp tubes and what tones each are good for, but I am still not getting any info about power tubes. If the tone is mainly from the preamp tubes then how much difference to the power tubes make? Still I haven't gotten a response about what exactly head room is. 

I like Metallica and Slayer very much. Other than that I don't listen to metal much. The rest is old school country and blues: Waylen, Cash, Muddy, Stevie, AC/DC, Hank Sr. and Jr. 

I have a set of JH EMGs in my Les Paul so those really help with the metal, and I just got an American Standard Strat. But really, a clean amp and a dirty amp are the way to go. However, the new bride wouldn't understand that one at all.

Still......wtf is head room???


----------



## Wilder Amplification

VAGINAGAS said:


> Well, yea I was sent a link about preamp tubes and what tones each are good for, but I am still not getting any info about power tubes. If the tone is mainly from the preamp tubes then how much difference to the power tubes make? Still I haven't gotten a response about what exactly head room is.
> 
> I like Metallica and Slayer very much. Other than that I don't listen to metal much. The rest is old school country and blues: Waylen, Cash, Muddy, Stevie, AC/DC, Hank Sr. and Jr.
> 
> I have a set of JH EMGs in my Les Paul so those really help with the metal, and I just got an American Standard Strat. But really, a clean amp and a dirty amp are the way to go. However, the new bride wouldn't understand that one at all.
> 
> Still......wtf is head room???



Headroom is power that is available but not being used. When you hit the guitar string, you notice the volume and punch change depending on how hard you strike the string. This is because the harder you strike it, the more voltage swing at the output you get.

But...there is a limit as to how high the voltage at the output can swing. The difference between the maximum available voltage swing and how high the output voltage is actually swinging is your headroom.

When you hit the limits of available headroom, you lose dynamic response as the output voltage cannot swing up any higher than the amplifier's maximum rated output voltage.


----------



## userofdsl40c

I just got the dsl40c and have been reading in here. This is my first really good tube amp though I've had a lot of solid state amps. What I need to do is understand what to do to keep the tubes in good shape.

Since these amps have to be biased does that mean we need to bring it to a tech just to change some tubes? That seems to me like too much trouble to maintain these amps. I always thought you could just get new tubes and put them in. Now I have to buy some device to bias the amp, or better yet take it to a tech? Jeepers. :Ohno:

Enlighten me.


----------



## VAGINAGAS

Wilder Amplification said:


> Headroom is power that is available but not being used. When you hit the guitar string, you notice the volume and punch change depending on how hard you strike the string. This is because the harder you strike it, the more voltage swing at the output you get.
> 
> But...there is a limit as to how high the voltage at the output can swing. The difference between the maximum available voltage swing and how high the output voltage is actually swinging is your headroom.
> 
> When you hit the limits of available headroom, you lose dynamic response as the output voltage cannot swing up any higher than the amplifier's maximum rated output voltage.


 
That is exactly the answer I was looking for. Thanks!


----------



## SaintFredrocks

Damn! I was told headroom was the distance from my legs to the bottom of the steering wheel.


----------



## Jensen

V1,V2,V3 and V4. Which tubes are these if im looking at the back of the amp? TSL60


----------



## MartyStrat54

Jensen said:


> V1,V2,V3 and V4. Which tubes are these if im looking at the back of the amp? TSL60



I sent this member a reply.


----------



## DragonSarc

Hey Marty and the gang!!! 
so I got bit by the bug and got me a 50th Aniv JVM 1 watter combo (JCM1C is on the way also), had it for couple of days and been playin dimed how long will the tube last on them since it will always be dimed?


----------



## MartyStrat54

Diming the amp doesn't correlate into fast preamp tube wear. I don't know the voltages that tube runs at, but that is more of a dictating factor. My guess is you should get a lot of service out of the tube. Also, the two 12AU7's should be running in a manner that is not taxing on them. After all, the amp is only generating one watt.


----------



## AbelsKeepeR

I have a 2012 model DSL 100H. When experimenting with the "V-Toobs" can I simply switch these out, without having to re bias or anything. Just switch one out, plug it back up, and listen? Simple as that? Is the DSL self biasing?

Thanks
Terry


----------



## MartyStrat54

Yes, V1 through V4 can be exchanged without it affecting the power tubes bias.


----------



## AbelsKeepeR

Cool, thanks Marty! You Rock Brother!


----------



## AbelsKeepeR

I've alway read about people experimenting with different tubes, and reading where alot of guys always switch out the stock tubes for better ones. My question here is, why does Marshall seem to swear by the "stock" cheaper chinese tubes, when for a few bucks more they could simply install "better" tubes in the first place? Seems like if I owned an amp company, and the most popular one in Rock History, I would go ahead and put in better tubes to begin with. I realize "amp tone" is highly subjective, as each headbangers ears can "hear" things differently, but still....

Also, I don't see very much mention of "Groove Tubes" here. At one time wherever you went you would hear about everyone using them, and you just don't hear that much about them anymore. Years ago I owned an original 80's JCM 800 head, and when I got it, it had groove tubes already installed. I liked the tone alot, and when they finally gave out, I took it to a famous local amp maker/builder, and he replaced them with EH tubes. I really never did dig it like I did before. Seemed sooo much brighter sounding. I guess I could have gotten used to the more "worn in" groove tubes, which may have also sounded brighter when they were new too. As I look back now I feel so "Stoopid". I sold that 800 halfstack for, get this "$600..This was like back about 10 years or so now. Who would have thunk it that an original 800 head would be worth what they are now. It's truely the only regreat I have in life now! lol


----------



## dugger

Hey Marty, little question for ya regarding my 2204.
I'm running into clean low input as a pedal platform for practicality for the variety of songs we do.(still sounds awesome)

I've read the low input completely skips first gain stage.

What are results/ramifications of V1 tube still in the amp OR removed from amp while running into low input?

In other words am I just burning a tube in V1 for no reason or does it need to be there regardless?


----------



## dugger

One more Martman,
The EL34's in 2204 are Svetlana but they have Fender logo on them.
(kinda old style Fender logo) 
Can you tell me anything about these?
Surely Marshall did not put them in there.
Could they be older than the hills or something?


----------



## MartyStrat54

Where did you read about the "bypassing of V1?"

As far as I know, all Marshall's use at least one side of V1 for the clean. V1 is the first gain stage and sets the table for the overall tone of the amp. If you pull it, I think you'll see what I mean.

It's obvious that the Fender/Svetlana's are not stock. Someone put them in there.


----------



## dugger

Thanks Bro,
Can't remember where i read that.
I'm glad it was wrong info.

(I was just wondering maybe how long ago it was that Fender branded Svetlana's like that)


----------



## MartyStrat54

It's hard to say. Amp manufacturer's will strike a deal with a tube producer for a large lot. Before they run out, they strike another deal and it may be with a different company, so it changes all the time. They could be as old as the 90's.

As for now, Fender acquired Groove Tubes in the summer of 2008. Fender sells all the old Groove Tubes under the Fender logo.

Before acquiring GT, Fender wanted to expand their accessories line and they bought tubes and they were relabeled Fender.

After all, Fender does not make an EL34 guitar amp.


----------



## dugger

Thanks again Marty


----------



## ORANGECAP

i have ruby el34b-str in a jcm 800. without even playing a guitar they get way to hot to touch an i just had it seviced. is that hot normal


----------



## MartyStrat54

If the amp has been serviced, I'm assuming the bias has been checked or adjusted. This being the case, power tubes do get hot and dissipate a lot of heat. It's normal.

You should not touch hot power tubes as they can cause burns.


----------



## keennay

Great thread!

Now which Shuguang for V1 are we talking about? 12AX7-A or B?


----------



## MartyStrat54

Here are the best Shuguang's that are available from Ruby Tubes.

Ruby Preamp & Rectifier Tubes | Magic Parts Co.

I like the 12AX7AC7 HG+


----------



## keennay

Oh wow, more options!

I have with me a couple of different tubes and so far here's my favorite configuration for my JMP 2203:

V1 - Shugaung 12AX7B (It just says 'CHINA' on it lol, so I'm guessing that's a Shuguang?)
V2 - Sovtek 12AX7WA (Originally had a GT-ECC83 but preferred the Sovtek)
V3 - Electro-Harmonix 12AX7EH

I've done a bit of Google-ing & I've read good things about Mullard NOS 12AX7's or Sovtek 12AX7LPS' being used as PI tubes for more gain. Now I don't really wanna pay an arm/leg for Mullard NOS tubes, but just curious what all have you tried as PI tubes?

I also have the following tubes in my TubeStore cart:
(3) Mullard 12AX7, (3) Tung-Sol 12AX7, (3) Shuguang 12AX7A


----------



## MartyStrat54

Keep in mind that the GT is also a Shuguang, just a different version. Your V1 Shuguang with "CHINA" on it are the one's that can be noisy. If you got a quiet one, they are good tubes. It's probably a Generation 8 Shuguang.

I don't really care for Sovtek stuff. Some people do. Instead of buying nine preamp tubes, you should just get three or four good ones. For your JMP, I would go with a couple of the Ruby Shuguang AC7 HG+ and use the EH in the PI. Or you could get a new JJ ECC83 for the PI. The Sovtek LPS is another popular PI tube.

I've tried all sorts of tubes in the PI slot. If you have good tubes, then you can always put one in the PI. However, I really like a high gain Sylvania Grey Plate for a PI tube. 

I also like a ribbed plate Telefunken for a PI, but if you have one of those, it should go in the V1 slot. Mullard or Amperex make great PI tubes as well. 

The main thing about a 2203 is that to get the very best crunch out of it, you need some high gain tubes in the amp. That's why I recommend the Ruby Shuguangs. For the money, they are really decent.


----------



## keennay

Thanks Marty, much appreciated.


----------



## keennay

MartyStrat54 said:


> Keep in mind that the GT is also a Shuguang, just a different version. Your V1 Shuguang with "CHINA" on it are the one's that can be noisy. If you got a quiet one, they are good tubes. It's probably a Generation 8 Shuguang.



I have no clue if the extra "noise" I'm hearing is attributed to my V1 China tube, but I'll keep that in mind.



MartyStrat54 said:


> I don't really care for Sovtek stuff. Some people do. Instead of buying nine preamp tubes, you should just get three or four good ones. For your JMP, I would go with a couple of the Ruby Shuguang AC7 HG+ and use the EH in the PI. Or you could get a new JJ ECC83 for the PI. The Sovtek LPS is another popular PI tube.



I definitely noticed a difference when swapping my GT ECC83 tube for a Sovtek, although I'm not sure I'd notice one if I swapped my V1 China w/ V2 Sovtek. My intention was to try 3 of the same preamp tubes in one amp, but I'm no longer sure that's the best route. My other JMP 2203 (with 6550 power tubes) has JJ ECC83's which I don't like.

The configuration there was:
V1 - Electro-Harmonix 12AX7EH
V2 - JJ ECC83S
V3 - JJ ECC83S

At first I swapped the Electro-Harmonix into V3 & didn't notice a difference, but man the amp sounded a lot better with the Shuguang in V1 & Sovtek in V2. I bet if I did a blind A/B test of this JMP 2203 with 6550 tubes vs. the other JMP 2203 with EL-34's, I wouldn't be able to decide which I preferred!



MartyStrat54 said:


> I've tried all sorts of tubes in the PI slot. If you have good tubes, then you can always put one in the PI. However, I really like a high gain Sylvania Grey Plate for a PI tube.
> 
> I also like a ribbed plate Telefunken for a PI, but if you have one of those, it should go in the V1 slot. Mullard or Amperex make great PI tubes as well.
> 
> The main thing about a 2203 is that to get the very best crunch out of it, you need some high gain tubes in the amp. That's why I recommend the Ruby Shuguangs. For the money, they are really decent.



Looks like I'll be purchasing 2 Shuguangs and at least one Slyvania & one Sovtek LPS. 

Thanks again.


----------



## MartyStrat54

This is interesting. I especially like the phase inverter data. 

Billm Analyzes 12A*7 Family Tubes in a Blues Junior


----------



## plexilespaul

hey marty i just dug a pair of old sylvania fat bottle 6ca7-el 34's....do you have experience with these tubes?
i want to put them in my 2204's jcm 800 (currently there are groove tubes in there). what should i expect tone wise with these puppies?
are these good tubes for the 2204 circuit?
thanks


----------



## MartyStrat54

Those are great tubes for a 2204. I ran a set in my 2204 until a week ago, I switched over to the TAD EL34's and gave the Sylvania's a break.

As long as they are strong (and they usually are) they should be just fine.

You will notice that the overall tone is smoother from the mids to the highs and there will be a little more top end sparkle. An EL34 is more throaty in the midrange, but doesn't have the bottom and top end response of the Sylvania's. If you need more mids, you can use the tone controls.

EVH used the Sylvania 6CA7's and he sounded pretty good.


----------



## EndGame00

Question about stock Marshall preamp tubes...


I've been experimenting with combination of preamp tubes to both of my DSL15 and Fargen Mini Plex

the DSL loves the JJ preamp on V1 and V2 and a JAN 5751 as PI

the Fargen loves the Marshall - Sovtek combination.

Can anyone tell me which manufacturer/brand/maker this one Marshall relabeled preamp comes from?

Marshall ECC83 VLVE-90067


----------



## MartyStrat54

Do you mean 00067?

VLVE-00067 ECC83S JJ Low Microphony Red Logo


----------



## EndGame00

MartyStrat54 said:


> Do you mean 00067?
> 
> VLVE-00067 ECC83S JJ Low Microphony Red Logo




I'm looking at the bottle itself and it says VLVE-90067 (mislabeled perhaps?). 

I tried to take a photo but it's out of focus.


----------



## MartyStrat54

I don't know of any Marshall labeled tubes beginning with a 9.

Post a clear picture of it over on the Preamp Tube thread. It will be ID'd.


----------



## EndGame00

I posted a photo of it on the preamp section. Thanks.


----------



## sccloser

What happened to the old tube discussion threads? I can't find them.

Marty and/or Alan.... What is a good 6L6 for a Fender Hot Rod Deluxe Amp?


----------



## MartyStrat54

The tube threads are in the Workbench section, but unfortunately they have been sort of inactive lately.

My favorite 6L6GC is the TAD. It is available in a short or tall bottle. Highly recommended.


----------



## sccloser

I was thinking about some NOS glass. Do you have anything for sale? I need to quit getting these non EL34 amps. I have a bunch of EL34's but no 6L6's.


----------



## MartyStrat54

I don't have anything. I really don't deal in NOS power tubes anymore. It's just so hard to find good matched sets.

Do you need two or four?

I left you a comment over on the Preamp Tube thread.


----------



## sccloser

Just two.


----------



## MartyStrat54

Well a matched pair is easier to score than a matched quad. Good luck.


----------



## Micky

[ame=http://www.youtube.com/watch?v=uKyVk92gwv4]New JJ 9 watt EL84? Feel free to ask Myles - YouTube[/ame]


----------



## MartyStrat54

That's pretty much my feeling. Do you recall Jon Wilder's thoughts on this same topic? Epic!


----------



## mickeydg5

Jon talked about tubes and states of tubes often.
Any thread in particular?


----------



## MartyStrat54

I wouldn't even begin to know where to look. Someone posted about the ELL84's and included some comments from Bob of Eurotubes. Jon went ballistic. It was very interesting. Jon called the tube for what it is, a marketing ploy.


----------



## mickeydg5

I hear you.
Oh that is the EL844, being 9 watts dissipation. I remember that one.


----------



## MartyStrat54

Yeah, I put an extra "L" instead of an extra "4." EL844.

Like Myles said and I concur, most guys with EL84 amps complain of lack of clean headroom. Putting EL844's in your amp will make this worse.


----------



## MartyStrat54

You know, I have to agree with the members that said it is better to do an Internet search for info on the forum. I quit using the search function about a year ago. Anyway, I found Jon's thread. It eventually got closed by Adwex.

http://www.marshallforum.com/workbench/26088-truth-about-jj-el844.html


----------



## paul-e-mann

How did I miss this thread?? Good tube info in post #1.


----------



## yladrd61

FYI: Watford Valves has NOS New 37 Code Tesla EL34s for 55 pounds>uk.a piece I am sure they can match a quad. If I didn't just get those XF2's I would be all over that !!!! 

PS: They also have NOS Phillips JAN 6L6WGB's I put some in my Bassman they Rock !!!


----------



## mickeydg5

Some of 6L6WGB tubes are nice. I have some Sylvania brown base JAN and they sound very similar to a nice set of TungSol 5881 (NOS).


----------



## MartyStrat54

I like the older Tesla's, but I'm not too keen on the later production stuff. They have a tendency to rattle.


----------



## yladrd61

I have a set of Teslas, I had them in my amp for 5 years and they still sound great. I never heard them rattle but of course I have a 1970 Super Lead so I would be kind of hard to tell, lol. I have NOS {$$$$$$} Mullards in there now  

Also those JAN Phillips 6L6 WGB, are military spec tubes that were made for use in Military Aircraft, they have a higher plate dissipation than 5881's, The only Data sheets I have seen say they are a 26W tube. Maybe You can come up with more info on them Marty. They sure sound good in my RI Bassman


----------



## MartyStrat54

Here is the Tung-Sol data sheet. I believe that Tung-Sol was the original military supplier for the WGB. 

Philips bought Sylvania and at that time Sylvania was the only US tube manufacturer still in business and their main customer was the military. Philips ECG tubes were Sylvania design and had the same spec's as the Tung-Sol's.

http://scottbecker.net/tube/sheets/087/6/6L6WGB.pdf

FWIW, lots of Tungsol military 5881's are labeled 6L6WGB.



> 5881/6L6WGB-This type originally was known as the 6L6WGB, and was designed for the US military. Nearly all were made by Tung Sol. The tube is a short flat topped tube with a brown base, and a large grey plate structure inside. These often had large top getter patches, but there are some with side getters, some have both top and side getter flashing. The design proved so popular that an industrial version was created and labeled the 5881. Both tubes are the same.


----------



## Remedylane

Very interesting read Marty. Although I have been playing for over 20 years, I just got my first all tube amp last year. It is a 1988 JCM 800 2205. I had my tech service it. He changed the filter caps, put new power tubes and biased it.. Just went over the amp in general. All of the pre amp tubes were Mullards.. One was microphonic so we replaced it. He had a few brands on hand and would let me play and tell him which brand I liked. Ended up being an Electro Harmonix. I assume when you say V1 you mean the preamp tube farthest to the left if looking at the back of the amp. That is where the Electro Harmonix is.. Am I correct in that assumption? Is V1 in the 2205 where ill get most of the tone changes from? Thanks in advance!


----------



## MartyStrat54

V1 is closest to the power transformer and the farthest away from the power tubes. It may or may not have a metal shield covering it to protect it from RF.

There are two versions of the 2205. Here is the tube layout for your amp.

Normal Channel: V1A and V2A and V2B

Boost Channel: V1A and V1B and V3A

Reverb: V3B and V4B

Effects Return: V4A

Phase Inverter: V5

12AX7's have two triodes, A and B. In your amp both the normal and the boost channels use V1A as the first gain stage. This is your most important tone tube.

If you are happy with the EH, then I would recommend that you try a Ruby 12AX7AC5 HG+ ($20). I would put it in V1 and the EH in V2.

Hope this helps.


----------



## Remedylane

Im a tad confused.. So which one is V1? I assume V1 is the brushed silver looking one as opposed to the chrome ones. They all have tube shields on them.


----------



## mickeydg5

Not all amplifiers are arranged the same, so you have to watch placement of tubes on the chassis and look at how they connect to the circuits.

The input jack connects to first stage components which connect to the first stage preamp tube (half) also usually called V1a.

The 2205 is trickier so watch where the tube wires run off to the board and circuits.


----------



## MartyStrat54

In that picture from left to right it is V1, V2 and V3 . V3A is a gain stage so it is grouped with V1 and V2.

Then continuing on, you have V4 and V5.


----------



## Remedylane

Awesome! That is what I thought. Thanks Marty. You guys have been so helpful and welcoming here. The knowledge I am gaining is awesome. So currently there is the EH in V1 and Mullards everywhere else. Going to get one of the Rubys you recommended and try it out. No gigs for 2 weeks so I have been in tweaking mode. I like the EH sound, but it was for sure a bit noisier than when there was a Mullard in V1.

One other question. How much do different pre amp tubes effect the reverb???


----------



## MartyStrat54

Generally, if one 12AX7 tube is used for the reverb, you can use a good utility tube in that slot such as a JJ or EH. Your amp shares V3 with the reverb and the final gain stage for the boost channel. The final gain stage for the boost channel is the least critical, so you can get by with about anything in this slot. One of your Mullard RI's will be fine in this slot.

The EH is a brighter tube, but I'm not a big fan of that particular tube. However, you seem to like a brighter tube and that is why I suggested the Ruby AC5 HG+ to you. It is the quietest current production tube I have tried. The less noise you have in V1 the better the tone will be.


----------



## Remedylane

Gonna send you a PM Marty. Whenever you have a free moment.


----------



## Eternal Scar

Hi Marty.I have a 1988 JCM800 2203 100watt head.I bought this with the matching cab off of the original owner in 1992.It has only ever had 1 tube change ever(original owner had it done)and has Groove Tubes in it now.I am not sure if the pre amp tubes are the original ones as I do not know how to tell.It still sounds good but after all these years I want to retube it.Can you steer a brother in the right direction on what kind of tubes I should be looking to get?Any help would be greatly appreciated!!Thanks!

Mark


----------



## MartyStrat54

Well have you ever drove a car for such a long time that you don't notice that the shocks need replaced and then when you get them replaced you are amazed at how great everything is? Same with tubes. Of course you didn't say how much the amp has been played? Tubes don't go bad unless they are being used.

I can only assume that the amp was played and therefore the tubes should be replaced.

I would recommend a set of TAD EL34B STR's (about $110 for a matched quad) for power and the Ruby 12AX7AC5 HG+ (about $20 per tube) for V1 and V2 and a Mullard RI (about $18) for V3.


----------



## Eternal Scar

MartyStrat54 said:


> Well have you ever drove a car for such a long time that you don't notice that the shocks need replaced and then when you get them replaced you are amazed at how great everything is? Same with tubes. Of course you didn't say how much the amp has been played? Tubes don't go bad unless they are being used.
> 
> I can only assume that the amp was played and therefore the tubes should be replaced.
> 
> I would recommend a set of TAD EL34B STR's (about $110 for a matched quad) for power and the Ruby 12AX7AC5 HG+ (about $20 per tube) for V1 and V2 and a Mullard RI (about $18) for V3.


TAD EL34B STR's?Is TAD the brand?I know someone selling a matched quad of Ruby EL34B STR's what are your thoughts on those?Any idea where I can get the preamp tubes you suggested?


----------



## MartyStrat54

TAD is a brand. It stands for Tube Amp Doctor. TAD is based in Germany. They design the tubes there and then they are made at the Shuguang factory in China.

The Ruby is a relabeled Shuguang EL34. The only difference between them is that the Ruby's are tested better by burning them in longer and therefore the risk of getting a bad tube is lessened.

The Shuguang and the TAD look the same, but the materials inside the tube are higher grade and supposedly the TAD's have a better vacuum.

I don't see a problem with you using the Ruby's.


----------



## Eternal Scar

MartyStrat54 said:


> TAD is a brand. It stands for Tube Amp Doctor. TAD is based in Germany. They design the tubes there and then they are made at the Shuguang factory in China.
> 
> The Ruby is a relabeled Shuguang EL34. The only difference between them is that the Ruby's are tested better by burning them in longer and therefore the risk of getting a bad tube is lessened.
> 
> The Shuguang and the TAD look the same, but the materials inside the tube are higher grade and supposedly the TAD's have a better vacuum.
> 
> I don't see a problem with you using the Ruby's.


 Thanks Marty!If I put these Ruby's in my Marshall do I have to get the amp rebiased since it already has EL34B's just GT not Ruby's?


----------



## MartyStrat54

Yes, when replacing the power tubes in the 2203, you want to adjust the bias.


----------



## Eternal Scar

MartyStrat54 said:


> Yes, when replacing the power tubes in the 2203, you want to adjust the bias.


 I bought the Ruby's now I just have to hunt down the pre amp tubes you recomended and time to get er retubed!Thanks again!


----------



## MartyStrat54

Let me know how it sounds. Don't over bias the power tubes. I like to bias at around 65 percent. Too hot of a bias can make a 2203 sound harsh.


----------



## Eternal Scar

MartyStrat54 said:


> Let me know how it sounds. Don't over bias the power tubes. I like to bias at around 65 percent. Too hot of a bias can make a 2203 sound harsh.


 My tech has it now Marty.I went with all the tubes you said and he is doing a cap job on it as well.As soon as I get it back I will let you know how it sounds,I'm sure I will be one happy camper!!Thanks again for all your help!


----------



## MartyStrat54

Not a problem. I'm sure it will kick some ass.


----------



## Vicious Amplification

Very informational and lots of great information there Marty. I just picked up a full set of JJ Power and pre amp tubes for my TSL rebuild. All matched sets.

(4) JJ ECC83-S / 12AX7
(4) JJ E34L (EL34)


----------



## MartyStrat54

Well I hope you don't mind if I comment on the JJ's.

The JJ E34L's are a very good tube for 80's rock/metal. I do not like the JJ EL34.

JJ ECC83's are the darkest sounding current production preamp. I only recommend them for V3 and V4 in a DSL/TSL.

If you like your TSL to be darker sounding, trust me it will with the JJ's in V1 and V2.

Personally, as far as CP tubes, I like the Chinese stuff. I would go with either a TAD 12AX7WA or a Ruby 12AX7AC5 HG+ in V1 with a Mullard RI in V2 and the JJ's in the two other slots. If you feel the amp is too bright, then put a JJ in V2.


----------



## Duffy49

MartyStrat54 said:


> Well I hope you don't mind if I comment on the JJ's.
> 
> The JJ E34L's are a very good tube for 80's rock/metal. I do not like the JJ EL34.
> 
> JJ ECC83's are the darkest sounding current production preamp. I only recommend them for V3 and V4 in a DSL/TSL.
> 
> If you like your TSL to be darker sounding, trust me it will with the JJ's in V1 and V2.
> 
> Personally, as far as CP tubes, I like the Chinese stuff. I would go with either a TAD 12AX7WA or a Ruby 12AX7AC5 HG+ in V1 with a Mullard RI in V2 and the JJ's in the two other slots. If you feel the amp is too bright, then put a JJ in V2.




I have found that a high gain amp can be very particular about which tube that it will get along well with in V1. Being a novice I bumbled around with a quite a few before I found one that satisfied V1 in my Peavey 6505+ combo. Some of them "squealed" ridiculously with high gain even at low volume.


----------



## FutureProf88

Hey Marty. I picked up an old 7025 for $6 at a music store a while back. If I PM'd you a pic would you see if you can ID it?


----------



## MartyStrat54

Yeah go ahead. Let me see it. Make sure it is a clear, large shot.


----------



## mickeydg5

Slap the picture in the thread.


----------



## MartyStrat54

Tube is an RCA 7025. Pictures were sent via email.


----------



## mickeydg5

Marty
What are your thoughts on 7025 tubes? What about as far as brands like RCA?


----------



## MartyStrat54

Well I used to think that the RCA 7025's were special, but I really don't feel that way anymore. When RCA introduced the 7025, it was a great idea since most heaters were AC. In it's day, the 7025 was the best tube for preamp stages. However, if you look up 12AX7 on Wikipedia, down at the bottom of the page you will see variants that were high gain, low noise and low microphonics.

12AD7 (October 10, 1955 - 225mA heater - low hum)
12AX7 (September 15, 1947 - like miniature 6SL7, A_v = 100)
12DF7 (A_v = 100, low microphonics)
12DT7 (A_v = 100)

(This is just a partial list, there are others as well.)

I don't know why these other low noise twin triodes did not have the same popularity as the 7025. A lot of the special low noise tubes were made in Japan in the mid to late 50's.

The 7025's main claim to fame is the spiral heater filaments. (Back in the good old days, most manufacturers didn't even bother to twist the heater pairs going to the socket.)

When the 12AX7A came out, the precision of manufacturing and the parts tolerances were such that it effectively replaced the 7025. Hence for about a five year period, you saw both P/N's on the tube until eventually only the 12AX7A P/N was used until the end of NOS production.

If you have an amp using DC voltage for the heaters, than a 7025 (and similar) tube becomes a moot point.

Are they still good tubes? Yes. I like the RCA or GE 7025's. I feel the reason they are so popular in Fender's (and were OE in the old Fender amps) is because they are a very smooth, clear sounding tube that imparts a clean tone. This works well for that classic, Fender chime.

I've also found that most RCA 7025's are not that stout. Out of all the one's I have sold, maybe a few dozen were what I would consider high gain on my B and K 707. Many that I bought NIB tested at around 80-82 percent and it wasn't uncommon for the two triodes to be off by a fair amount. I did run into an exceptional batch that I bought on EBAY. I bought three, 5 tube sleeves, all the same codes and most of them tested at 30-30. One was a 32-35 which is the stoutest that I've ever seen.

In conclusion, there is nothing wrong with using a 7025. In a ways it is sort of like a lower gain Raytheon Black Plate, very neutral sounding. The 7025 was a great idea when it was introduced. It was perfect for the budding hifi market. It served its purpose "in that particular era" of tube history.

However, I prefer many other tubes over a 7025 as far as guitar tone.


----------



## mickeydg5

Good assessment there. I had noticed the usage in Fender. Thank you for the information.


----------



## MartyStrat54

And I thank you for all your information. It is greatly appreciated.


----------



## Jack92CH

Hey, guys. I'm looking at Genalex's Gold Lion ECC83 "Premium" preamp tubes. Does the quality justify the price, or is it a bunch of brand hype and snake oil? They're going for $43.95 a piece, which isn't outrageous, but obviously I'd like to save a few bucks if possible.

I just got my 2203X serviced and it's breathing fire like never before, but I want to swap out the Mesa branded 12AX7s in the preamp for something that'll do the amp justice. I'd like a little more sizzle and spongy-ness if at all possible, so I'm wondering what my options are without spending more than necessary but still getting an awesome tube or three.

Thanks


----------



## MartyStrat54

If you are going to spend $44 for a CP tube that isn't as good as a $22 Ruby 12AX7AC7 HG+, you might as well buy some used vintage tubes for your amp.

These high priced CP tubes are a brand based marketing ploy. I got some Northern Electric 12AX7's ($58) and two out of the four were lopsided and one was microphonic. Bottom line, you can pay $45 for a CP tube and it can still be a dud.


----------



## Jack92CH

Good to know. What would you say are the best CP preamp tubes? I see you mentioned Ruby already.


----------



## MartyStrat54

Well it is starting to get a little screwy since New Sensor started relabeling Chinese tubes to be sold under their Russian brands. There are several companies selling the exact tube at varying prices.

The Ruby 12AX7AC7 HG+ has been discontinued, but it is still available from Doug's Tube. He also sells the Ruby AC5 HG+ as well. Both of these tubes are low noise/high gain. These sell for around $22.

Another nice tube is the TAD 12AX7WA. I know it can be bought from Mojotone.


----------



## Jack92CH

Cool, Marty. Thanks. While looking around I saw TAD has a lot of preamp tubes to choose from, with certain types being recommended for certain positions. The TAD 7025 WA Highgrade looks interesting, but again, I don't know well enough to tell the difference between brand hype and the real deal.

I'd like as much gain as possible to be on tap for my 2203X. Am I better off sticking with anything labeled 12AX7/ECC83 or can these other types be just as awesome?

Thanks again, man.


----------



## MartyStrat54

A "WA" will work fine. It is more of a marketing strategy by TAD.


----------



## sct13

Hello again, 

I just ran across a FoMoco (Ford Motor Co) 12ax7 

Any good? I wont have the opportunity to plug it in for a bit. Just wondering who made it? 

Someone just gave me some 12ax7 \' and this was in the bunch, never new they even existed.


----------



## MartyStrat54

Well Ford was affiliated with Philco. That would be my guess.


----------



## sct13

oh yea... forgot all about Philco.... I think they may have got into refrigerators at one point....


----------



## MartyStrat54

Yeah I just did a quick check and it's a Philco.


----------



## MartyStrat54

The new Martimus Maximus tee shirts have been delivered and looking good.

Mr. Chuck Harmon.






My friend Paul Roper.






Thanks to those who bought a shirt. I think they look great.


----------



## SixtiesFan

Hey Marty, great thread. I like the T on Chuck Harmon...and the doubleneck.
I'm new to tube amps. Just got a dsl40c which I love. But I'm retired and on a budget. I love Keef, Hendrix and Page's sounds, have American Standard Strat and Tele and an LPStudio. Could you or Chuck point me in a direction on tubes for esp. Jimi/Jimmy tones. That's what's been in my head for 40 some years now. I can't afford to experiment with zillions, but prefer to buy fewer High Quality tubes. As a former head of QC for a Mil Spec Connector Co., I hope I can afford JAN quality. I play almost exclusively on triode setting in a small room.

Thanks.


----------



## MartyStrat54

Tony Kinder and his daughter Amelia in Turkey. Taking Martimus Maximus to all points on the globe.


----------



## MarshallDog

Marty, 

IF you were going to buy a set of new production 6550's which ones would you buy:

1. JJ 6550
2. Tung-Sol Re-issue

I may convert one of my JMP 2204's back to 6550's for the hell of it. Thanks for your help.


----------



## MartyStrat54

Well if it were my amp I would buy the TAD 6550A STR. Yep, they cost $60 each, but they are the best 6550 out there and maybe as good as the old NOS GE6550A.

Tube Amp Doctor (TAD) 6550A-STR Vacuum Tube

Now out of the two you were looking at, I would go with the Tung-Sol at $37 each. It is built similar to the TAD in the fact that it is a triple getter tube with the ST style bottle. The TAD uses a straight bottle.


----------



## solarburn

Marty those Black Martimus T's look excellent. Let me know if/when you do another run. I'll be getting one...or 2 hehe.

Great pics!


----------



## MartyStrat54

Joe are you still fitting in an XL?


----------



## solarburn

MartyStrat54 said:


> Joe are you still fitting in an XL?



Yeah...I should be able too...LOL.


----------



## yladrd61

MartyStrat54 said:


> Well if it were my amp I would buy the TAD 6550A STR. Yep, they cost $60 each, but they are the best 6550 out there and maybe as good as the old NOS GE6550A.
> 
> Tube Amp Doctor (TAD) 6550A-STR Vacuum Tube
> 
> Now out of the two you were looking at, I would go with the Tung-Sol at $37 each. It is built similar to the TAD in the fact that it is a triple getter tube with the ST style bottle. The TAD uses a straight bottle.



I like the TAD 6550A STR a lot get very good late Jimi tones on the low input of my 1980 2203 with a Strat Fuzz Face and Mega Vibe. Thank you for the T shirt Marty


----------



## MarshallDog

MartyStrat54 said:


> Well if it were my amp I would buy the TAD 6550A STR. Yep, they cost $60 each, but they are the best 6550 out there and maybe as good as the old NOS GE6550A.
> 
> Tube Amp Doctor (TAD) 6550A-STR Vacuum Tube
> 
> Now out of the two you were looking at, I would go with the Tung-Sol at $37 each. It is built similar to the TAD in the fact that it is a triple getter tube with the ST style bottle. The TAD uses a straight bottle.



Great info Marty, which one of the (3) would have the darkest, non-in-your-face, less ear piercing tone? I like JJ E34L's because they are darker so I just figured the JJ 6550's would follow suit.


----------



## MartyStrat54

Well the JJ E34L's are not really what I would call an EL34. They are a variant. 

I wouldn't say the JJ is dark sounding, rather mediocre sounding. Not as vibrant and transparent as the other two. If you go to The Tube Store and look at the JJ 6550, no one has left any feedback on it. That would be a red flag to me.

You are going to set your tone with V1. If you prefer a darker tone, then use an RFT or a JJ in V1. Both the TS and the TAD have a wide frequency response that is similar to a 6L6GC.

However, as I have said many times, running a 6550/KT88 in a typical 50/100 watt Marshall is going to result in a somewhat sterile sound due to that fact that you are taking a high wattage tube and biasing it as a 25 watt tube. This results in a cold bias and the true tonal characteristics of the tube are not achieved.


----------



## MarshallDog

MartyStrat54 said:


> Well the JJ E34L's are not really what I would call an EL34. They are a variant.
> 
> I wouldn't say the JJ is dark sounding, rather mediocre sounding. Not as vibrant and transparent as the other two. If you go to The Tube Store and look at the JJ 6550, no one has left any feedback on it. That would be a red flag to me.
> 
> You are going to set your tone with V1. If you prefer a darker tone, then use an RFT or a JJ in V1. Both the TS and the TAD have a wide frequency response that is similar to a 6L6GC.
> 
> However, as I have said many times, running a 6550/KT88 in a typical 50/100 watt Marshall is going to result in a somewhat sterile sound due to that fact that you are taking a high wattage tube and biasing it as a 25 watt tube. This results in a cold bias and the true tonal characteristics of the tube are not achieved.



Hmm, I see! maybe I shouldn't consider 6550's then??? Something to think about.


----------



## mickeydg5

I do not think that is fair concerning 6550 tubes being most tubes are not used at maximum operation ratings. An electronic device has a range of operation. As long as it is being used within that range it is normal. I do believe or agree though that some have one or more sweet spots.

The mentioned tubes are being used within their range of operation in this amplifier. 

There is another thread about EL34 - 6550 - KT88 use going on. As I stated in the other thread, a user either prefers one type or another in a specific amplifier design. One person's sterile can be another person's clean headroom. There are those that prefer 6550/KT88 to 6CA7/EL34 types. It is the user's implementation and preference that governs the choice.


----------



## MartyStrat54

Well I don't know if you are going to be able to hit the sweet spot on a 6550/KT88 running it as a 25 watt tube. 

I've found that if you take a 6L6GC amp and bias it around 55 percent, it sounds a lot like a 6550 running cold.

However, I will agree about one's tonal preference's. Many metal players prefer this tone, hence the Kerry King SIG amp with KT88's.


----------



## mickeydg5

Yes, I agree.
It is kind of like a Marshall with a Fender attitude.

I also use that term sweet spot loosely. Again, one person's sweet spot might be another person's too woody, or whatever lingo they use. You know what I mean.


----------



## MartyStrat54

Very true, Mickey.


----------



## John 14:6

MartyStrat54 said:


> Well the JJ E34L's are not really what I would call an EL34. They are a variant.
> 
> I wouldn't say the JJ is dark sounding, rather mediocre sounding. Not as vibrant and transparent as the other two. If you go to The Tube Store and look at the JJ 6550, no one has left any feedback on it. That would be a red flag to me.
> 
> You are going to set your tone with V1. If you prefer a darker tone, then use an RFT or a JJ in V1. Both the TS and the TAD have a wide frequency response that is similar to a 6L6GC.
> 
> However, as I have said many times, running a 6550/KT88 in a typical 50/100 watt Marshall is going to result in a somewhat sterile sound due to that fact that you are taking a high wattage tube and biasing it as a 25 watt tube. This results in a cold bias and the true tonal characteristics of the tube are not achieved.


 I am one of the guys that likes to darken up bright Marshall amps. I had been using JJ 12ax7's until I came across the RFT 12ax7's. They are like JJ's, but with WAY more harmonic content, gain and dynamics. I just bought a Randall/George Lynch combo amp that I am currently having modded with a choke, new (upgraded) caps and filter caps. This is going to run me around $250. I will talk to you about tubes as soon as the dust settles from buying the amp and the mod work. Once I get some great tubes in there the amp is going to be a little MONSTER.


----------



## MartyStrat54

Well I just scored a large lot of used RFT's from Ukraine. I should have them in a couple of weeks.


----------



## John 14:6

MartyStrat54 said:


> Well I just scored a large lot of used RFT's from Ukraine. I should have them in a couple of weeks.


I have been getting them off Ebay from Bulgaria and Romania, but the quality has been hit and miss. Great tubes mixed with bad tubes. I plan to go through you in the future Marty.


----------



## MartyStrat54

Yeah I bought 20 NOS RFT's a while back from Bulgaria and when I got them they were like 70 percent tubes. I ended up getting a partial refund on them. They are still good tubes and I priced them accordingly.

I saw a guy selling a NIB Edicron labeled tube and I noticed it was an RFT. I got it today and it tests around 66 percent on one side and around 69 percent on the other side. The tube is definitely NOS, but it has low test scores.

I get a little nervous buying from overseas. I have a guy in Germany that I trust and a guy in Russia, although he hasn't had anything good in a while. It's about 50/50 when buying from these overseas sellers. The problem is the shipping costs involved. I have yet to have to send any tubes back. I have always gotten a partial refund.


----------



## Codyjohns

These look like a good set of power tubes for the Major's next tune-up. 

Any thoughts on the Mullard KT88's ??

www.thetubestore.com - Mullard KT88 Audio Tubes


----------



## yladrd61

Michael RT said:


> These look like a good set of power tubes for the Major's next tune-up.
> 
> Any thoughts on the Mullard KT88's ??
> 
> www.thetubestore.com - Mullard KT88 Audio Tubes



I have heard good things about the new Genelex Gold Lion KT88s you may want to wait for some more reviews on this new "Mullard"


----------



## Codyjohns

yladrd61 said:


> I have heard good things about the new Genelex Gold Lion KT88s you may want to wait for some more reviews on this new "Mullard"



Most of my friends that own Majors love the JJ KT88's, I have them in mine right now.

Yeah, I'm going to wait for some reviews on the Mullards first.
There's just nothing out there right now on them.


----------



## yladrd61

I have heard great things about the Shuguang Treasures also but they are $pendy


----------



## Charlz

Hi, new here.... my JCM 2000 dsl has E34L 'low' tubes in, if I put in 'highs' (and have it biased) will I notice a difference? 

Thank you in advance!


----------



## MartyStrat54

I believe Mickey answered your question in your thread.


----------



## Söulcaster

MartyStrat54 said:


> I've found that if you take a 6L6GC amp and bias it around 55 percent, it sounds a lot like a 6550 running cold.
> 
> .


That would explain why my old JCM900 was the closest sounding amp I've ever heard to my AFD100? That made no sense eh? Nvm

Peace


----------



## bassistbobby

This is a GREAT article. Putting it all here is a great gift to all who are into tube amp ownership. This goes to the important subject of how to really enjoy your amp, not to just use it.

Being a JCM900 HGDR owner, I would just add that, in my own experience, changing my phase inverter tube, which is V3 in a JCM 900, to a long or medium plate tube, caused one of the biggest differences in tone I had come across in my own process of rolling my preamp tubes. I also discovered using a V2 tube with slightly higher emissions than my V1 tube, tended to smooth out the gain.
I have never read anything by anybody who says they've had the same experience, or who agrees with me. But this works for me every time. 

Anyway,.... GREAT article Marty. Where were you back in '06 when I first bought my Marshall...? LOL. This type of knowledge back then would have saved me a lot of time, money, and grief.


----------



## Metroman

I bought a Metro amps Limited Edition GMP45 Limited Edition. It has NOS GEC KT66's and Modern Mullard Preamp and Rectifier tubes.

I replaced the GZ34 with a 1961 NOS Mullard Fat Base.

Ive got a bunch of tubes and I have 14 NOS Mullard 10M Gold pins and am wondering if 3 of these would be the best choice for the amp?

I also have 11 NOS Telefunkens I haven't tried yet and I know the only way to find out is to try them.

Should I put a more transparent tube in v2 and v3 ? and Keep the 10M in v1 ? Or 3 10M's?

Im going towards the 3 10M's. Any advantage/disadvantage running the Midrangy Mullard 10M and transparent Telefunkens together ?


----------



## MartyStrat54

The best thing is to roll them. 

I would start out with a 10M in V1 and Tele's in V2 and V3.


----------



## mickeydg5

Damn Metroman, you have some heavy hitter tubes in your collection.

No one mentioned smooth or ribbed Telefunken. From what I have gathered that usually makes some difference.


----------



## yladrd61

Metroman said:


> I bought a Metro amps Limited Edition GMP45 Limited Edition. It has NOS GEC KT66's and Modern Mullard Preamp and Rectifier tubes.
> 
> I replaced the GZ34 with a 1961 NOS Mullard Fat Base.
> 
> Ive got a bunch of tubes and I have 14 NOS Mullard 10M Gold pins and am wondering if 3 of these would be the best choice for the amp?
> 
> I also have 11 NOS Telefunkens I haven't tried yet and I know the only way to find out is to try them.
> 
> Should I put a more transparent tube in v2 and v3 ? and Keep the 10M in v1 ? Or 3 10M's?
> 
> Im going towards the 3 10M's. Any advantage/disadvantage running the Midrangy Mullard 10M and transparent Telefunkens together ?



I ended up going with a strong Blackburn I63 in V1, a Matsushita Black Plate in V2 and a CP Mullard in V3 on my GPM45..... My advice start with Martys suggestion and roll every preamp tube you have through each position and you will know which one you like best in each position.


----------



## Metroman

I ended up using the 3 Mullard 10M 12AX7's.

They just seemed to sound better to my ears. More Mids I believe and were also the Quietest tubes of the bunch.


----------



## yladrd61

I think I saw those 10M's on ebay I hope you didn't pay too much for them.... I also found that I like mismatched power tubes in this amp with the higher current draw in V4  I have some Shuguang Treasure KT66-Z in mine with about a 5 ma mismatch.....


----------



## Metroman

Yeah I got it off Ebay. It tested over 93% and all parameters of it were really good.

I also sent it off and had it independently tested as it had a 30 day money back guarantee.

It tested as advertised. 

I already had 2 of the Standard Pin Mullard 12AX7 10Ms and bought this 1 because they were originally tested at the factory for tight tolerances and microphonics. And the tubes are dead quiet.

Well worth the money and I get it cheaper ( Still Expensive ) than Ive seen anyone else have them for. both of the standard pin 10M's test 86% and 89%


----------



## EADGBE

I've tried all kinds of tubes and I've settled on Sovtek 12AX7LPS for preamp and SED EL34 for power in my TSL602 combo. Now that SED is no longer making EL34s I'm thinking either JJs or Rubys.


----------



## Magictwanger

EADGBE said:


> I've tried all kinds of tubes and I've settled on Sovtek 12AX7LPS for preamp and SED EL34 for power in my TSL602 combo. Now that SED is no longer making EL34s I'm thinking either JJs or Rubys.



Shuguang El34m is a good Mullard copy. They are also re-branded as Groove tubes El34m with better testing!


----------



## EADGBE

Magictwanger said:


> Shuguang El34m is a good Mullard copy. They are also re-branded as Groove tubes El34m with better testing!



I'll look into them.


----------



## EADGBE

Journey to the inside of a tube.

https://www.youtube.com/watch?v=WnZRJjmOZb8


----------



## Jaymz E

I ran across some old slightly used Russian 6n14n/el84s from the 70s for $25.00 an octet and have been using them in my Orange AD30tc and my Peavey Blues Classic 1x15 and they sound better than the PM Chinese and the regular Sovtek el84s. I put them in these amps about 2 months ago and they are still going strong.


----------



## MartyStrat54

I sold those a lot. They are very good, especially the older ones.


----------



## wallythacker

My two music stores, (I alternate cities) are very poor in keeping stock. One store at least as a pair of Electro Harmonix 12AXZ. Everything else, except for some Mesa EL84 Boogie output tubes scattered haphazardly around a display unit, has to be ordered. I don't understand that.


----------



## Attila_B

Hi Folks New to the forum from South Africa and thought I would share some info concerning Pre-amp tubes....I can't take all credit for some of the info below, as I don't know who the original authors are, full credit and kudos goes them...............anyway so here goes:

*Valve comparison*: From an Guitar players perspective 











*Graph Interpretation *

All 12AX7s have an amplification factor (µ) of 100 ("high-mu"). Ideally every 12AX7 should yield the same gain when placed in the same circuit. However, in reality there are comparative gain differences among 12AX7s.

This graph is based on the average gain and noise measured from different tube brands, using the same number of samples for each brand. It should not be assumed that every single 12AX7 from a specific brand will exactly match its place on this graph.

The gain rating is only a relative reference (e.g. a rating of "10" does not mean ten times louder than a "1").








Numbers in parenthesis represent the average gain rating over the entire audio frequency range (Low, Mid, and High)

Voltage Gain Rating Noise Rating 
10 = High Gain
1 = Low Gain 10 = High Noise / Microphonics
1 = Low Noise / Microphonics


Further, *Why do Tubes sound different?* 

"It’s the RP-value, NOT the MU-value that’s Important!
To many people, the most important characteristic of a vacuum tube is its Amplification Factor (mu). Unfortunately, this is not true.

Of the vacuum tubes’ three operating characteristics – Dynamic Plate Resistance (rp), Transconductance (gm) and Amplification Factor (mu) - two are explicit values and one is an implicit value. The gm and rp values are explicit because they come directly from the tubes’ actual operating voltages and currents. The mu value, however, is an implicit value that is mathematically-derived from the product of the rp and gm values:

mu = gm * rp

Gm and rp are almost (but not exactly) inversely related. That is, as gm increases with increasing plate current, rp proportionately decreases. This inverse relationship causes mu to be virtually a constant that typically varies less than 10-15%.

The vacuum tube operating characteristics gm, rp and mu are “open-circuit” values, that is, they are calculated with NO external loads applied. In the real world, however, tubes are operated in circuits having both input and output loads. It is the effects of these “loads” (especially upon the plate) that make rp more important than mu. Here’s why...

When resistances are connected in parallel (symbol “||”), their resulting resistance is always LESS than the smallest resistance value. For example, consider two resistances, A = 10K ohm and B = 100K ohm, connected in parallel:

R = (A||B) = (A*B)/(A+B)
R = (10K*100K)/(10K + 100K) = 9.09K ~ 9.1K ohms

The same thing happens when a tube is operated with a plate load resistor (RP), its rp value is “loaded” in the same fashion as resistance-B “loaded” resistance-A in the example above. For instance, operating a 12AX7 (rp = 62.5K ohm) with a 100K ohm plate load resistor produces a circuit gain of only 61.5, not 100!

Why? Because, the ‘effective’ plate resistance (rp’) is no longer 62.5K ohms – it’s 38% LESS – only 38.5K ohms:

rp’ = rp||RP
rp’ = (62.5K*100K)/(62.5K + 100K) = 38.46K ~ 38.5K ohms

...where:

rp = Tube dynamic plate resistance, ohms (12AX7: 62.5K ohm)
RP = Circuit plate load resistance, ohms (typically 100K ohm)

Now, when tube gm is multiplied times rp’ a much LOWER amplification factor (mu’) value is obtained because of the LOWER ‘effective’ rp’ value:

mu’ = gm * rp’

...for 12AX7 gm = 0.0016 A/V, then:
mu’ = (0.0016 * 38.5K) = 61.5

And, when the output loading of the NEXT circuit (tube, tone stack, etc.) is included, the effective plate load becomes even LOWER. For example, assume the 12AX7 plate load resistor RP = 100K ohm feeds its signal into a tone stack having a resistance value of Ro = 500K ohms. Now, rp’ becomes three loads in parallel:

rp’ = (rp||RP||Ro)
rp’ = 1/( 1/rp + 1/RP + 1/Ro )
rp’ = 1/( 1/62.5K + 1/100K + 1/500K ) = 35714.3 ~ 35.7K
mu’ = (0.0016 * 35.7K) = 57.1

Thus, while the “open-circuit” gain of a 12AX7 is 100 with no load, its gain in a “real world” circuit (tube with loads) will be nearer to 60 (ie: 57-62), depending upon RP and Ro.

*SUMMARY:* “Mu is what the tube (alone) is capable of...Mu’ is what you actually get (in a circuit).”

Additionally, just as circuit AMPLIFICATION is dependent upon rp, so also is circuit FREQUENCY response or BANDWIDTH (BW), ie:

BW = 1/(2*PI*R*C)
...where: R = rp||RP||Ro

So, whenever we “swap” tubes, it’s the rp value of the new tube interacting with the RP, Ro, R and C values of the existing circuit that causes the sometimes “subtle” changes in amplification (gain) and tone (frequency response) that we hear.
And, here’s why...

The rp’ values shown in Table 1 represent preamp tube operation with circuit load resistances of RP = 100K ohms and Ro = 500K ohms, ie:

rp’ = (rp||RP||Ro)

The illustrative bandwidth (BW) values shown in Table 1 were calculated using R = rp’ and an assumed constant fictitious capacitance value of C = 446µF, ie: 

BW = 1/(2*PI*R*C)
where: R = rp’ and C = 446µF

*Table 1 - Preamp tubes sorted by MU values*.






As you can see, the greater the rp’ value, the lower the bandwidth! Which means that tubes with LOW rp values (and thus circuits with LOW rp’ values) will have greater BW and frequency response and proportionately less loss-of-gain (ie: mu’) than tubes with HIGH rp values. Table 2 re-orders the preamp tubes listing by their BW, in descending order.

*Table 2 - Preamp tubes sorted by BW values.*






Thus, substituting a 5751 for a 12AX7 (or ECC83, 7025, etc.) typically reduces circuit gain by 28% and slightly increases BW by 4%. Similarly, substituting a 12AY7 for a 12AX7 reduces circuit gain by almost half (45%) but nearly doubles the BW. And, remember, the greater the BW, the more “sparkle” and “chime” we’re likely to perceive.

Why only “....likely to perceive”? Because, changing one preamp tubes’ BW does not affect the BW of ANY of the subsequent tubes along the signal path. There might be more frequencies in the drive signal to the following tubes but they will not (usually) be able to pass along those added frequencies to the speaker(s) because their BWs have not changed.

That is ‘why’ swapping preamp tubes seemingly produces vague and subtle, instead of dramatic, tonal changes, while swapping output power tubes (the last tubes in the path) often produces VERY noticeable sonic changes.

...an "old" USN electronics proverb goes:

SHORT = infinite BW, because there's no R working with C to cause an RC rolloff.

OPEN = zero BW, because there's infiinite R working with C to cause immediate RC rolloff.

However, in the 'whole' amp, there's always the inductance ( L ) of the audio output transformer (OT) to consider to, which typically is *the* limiting factor for both LOW(f1)- and HIGH(f2)-cutoff frequencies!" But then again they are designed for a specific application which is always a delicate balance. 

Hope you found the above interesting and useful ...... Attila


----------



## Joe6BG6GA

Greetings to all. I have found that a 12BZ7 gives a little more drive in 12AX7 driver/ phase inverter applications. However this type takes a little more heater current. You might like the change on sound.


----------



## Joe6BG6GA

Hey guys..a lot of great feedback here. For what its worth.I have found that RCA NOS 12AU7A tubes give good punch as the driver in Marshall Majors.


----------



## sloan_amps

Recently, I started going through my tube stash and found a couple of made in USA 12AX7 tubes that I didn't have marked. Most of the writing is worn off except for just enough to make out the 12AX7 and USA parts.

Can someone please help me identify these, like who made them and I know it may be a long shot but perhaps how old they are?

Both tubes are identical except one has "13" on the bottom and the other has "24".










Thanks in advance,
Don


----------



## MartyStrat54

Those are late 60's GE 12AX7A's.


----------



## Duffy49

I just got my DSL40C back from Full Custom Music near Harrisburg, Pa, and it sounds great. I don't want to mess with the tubes at this time, but I am going to lay in some extras as Marty suggests, for future use.


----------



## sloan_amps

MartyStrat54 said:


> Those are late 60's GE 12AX7A's.



Thanks for the info Marty! I figured if anyone would know it would be you.

I've had those tubes so long I had completely forgotten about them. I believe those may very well be ones that I took out of a '65 VibroChamp that I used to have.


----------



## MartyStrat54

We'll probably be seeing more of each other very soon.


----------



## sloan_amps

I recently won an auction on eBay for a handful of old made in USA tubes. In testing them, I found one of them is a Tung-Sol 12AX7WA with short black plates, not the usual taller grey plates I normally see. This thing tests off the charts! It tests stronger than any tube I've ever tested, especially new ones. I'm going to have to save this tube for something special!


----------



## MartyStrat54

Those are the sort of V1 tubes that turn a JMP/JCM into a monster, especially the 2203 and 2204.


----------



## Dannyz

Marty, which EL34 do you recommend for an earlier breakup without the need of cranking the volume pot in a MV Marshall? Does exist an el34 with el84´s characteristics?


----------



## Joe6BG6GA

Greetings to all and happy Holidays. I have found that "new"production EL34 pentodes are mush less forgiving of screen grid voltages in excess of 450-475volts.


----------



## MartyStrat54

Dannyz said:


> Marty, which EL34 do you recommend for an earlier breakup without the need of cranking the volume pot in a MV Marshall? Does exist an el34 with el84´s characteristics?



As far as early breakup I will tell you to try a GT EL34 with a low rating.

Groove Tubes® - Hear The Difference



Joe6BG6GA said:


> Greetings to all and happy Holidays. I have found that "new"production EL34 pentodes are mush less forgiving of screen grid voltages in excess of 450-475volts.



The current Chinese Shuguang tubes are rated at 500V on the screens. I did a review of the TAD (Shuguang) EL34's using forum members and these tubes were tried in various amps. Some of these members switched over to TAD after trying their EL34's and so far no one has had any issue. I know several dozen pro guys that are using TAD's without any issues.

Screens can operate above their max rating (to a point) without failure. However, the life of the tube will decrease.


----------



## Dannyz

MartyStrat54 said:


> As far as early breakup I will tell you to try a GT EL34 with a low rating.
> 
> Groove Tubes® - Hear The Difference
> 
> 
> 
> The current Chinese Shuguang tubes are rated at 500V on the screens. I did a review of the TAD (Shuguang) EL34's using forum members and these tubes were tried in various amps. Some of these members switched over to TAD after trying their EL34's and so far no one has had any issue. I know several dozen pro guys that are using TAD's without any issues.
> 
> Screens can operate above their max rating (to a point) without failure. However, the life of the tube will decrease.



Thanks Marty! ive got another one for you...what are you thoughts about the Electro Harmonix El34 in Marshall amps? i know that Bray amps use those on his plexi clones with great results. Do they break up earlier than TADs or Shuguangs? Here in my country is almost impossible to find low rating GTs. Thanks 4 your time!


----------



## groovenev

I' own a 74 1987 MKII 50w Lead I bought it new in 74. Caution! Don't use Groove Tubes!! They won't work based on my testing them. I tested two of them and both red-plated after 5 minutes. Bias level scale setting: scale is 31-44 at grid 400V +- I set it to .034 and GT-EL34's red-hot-plate in socket 1- after 5 minutes of playing. Two different GT-EL34s were tested same results. 
I have NOS 1986 Mesa EL-34/6CA7's installed in it now, sound great: punchy, articulate, and lot of tone control, smooth tone. I set the bias at 37' on the scale nice and warm but not too hot to shorten the life of the tubes.


----------



## Coronado

groovenev said:


> I' own a 74 1987 MKII 50w Lead I bought it new in 74. Caution! Don't use Groove Tubes!! They won't work based on my testing them. I tested two of them and both red-plated after 5 minutes. Bias level scale setting: scale is 31-44 at grid 400V +- I set it to .034 and GT-EL34's red-hot-plate in socket 1- after 5 minutes of playing. Two different GT-EL34s were tested same results.
> I have NOS 1986 Mesa EL-34/6CA7's installed in it now, sound great: punchy, articulate, and lot of tone control, smooth tone. I set the bias at 37' on the scale nice and warm but not too hot to shorten the life of the tubes.


 
I have that same amp (same year too!), and it has quickly become my favorite amp. I love trying different tubes - what tubes do you prefer in your preamp? Thanks!


----------



## groovenev

Coronado, They are great amps! Very reliable go-to Marshalls. On the Pre-Amp I have an really old RCA 7025 GV in V1 from the 60's! really strong tube






These are kind of a rare tube - I have a few of them they really get you nice warm mids. I use one in my Vox AC15 pre-amp as well. 

V2 and V3 I'm using Old Mesa 7025 STR's they are very quiet tubes and low microphonic properties. It originally had old Mullard' 12ax7's in there until they died at show when a cold brew came in contact with them uhhh  everyone raves about the Mullards but honestly I would say having the old RCA in V1 gives it the same sound quality.






I do have more vintage tubes but these two Mesa's are really up front sounding and with the old RCA in V1 the amp roars!

-G


----------



## mickeydg5

I was looking at your old RCA in V1 and I am pretty sure that is perhaps a Philips or Mullard tube.
Does it have or what are the codes on it?


----------



## groovenev

mickeydg5,

Yes, it very well could be... I read that many of the RCA during that period were supplied by other manufactures. This tube certainly has the same tonal charistics as an old Mullard>> really warm! I can't read the markings on it any more, other than what you see on it. The other side is ECC83.

-G


----------



## Rider1260

So I finally got to try out my new to me TSL 100  and I am looking forward to trying out some new/different tubes to get the most out of the amp ( also looks like the stock tubes are still in it ) 
I do have one funny question on a TSL 100 looking from the rear which socket it which 
I am thinking that V1 is the far left ( farthest from the power tubes ) with V2-V4 going left to right, can't seem to find the info anywhere all my other amps have labels of some kind or its listed in the owners manual 
Not Marshall it seems


----------



## ty220

Rider1260 said:


> So I finally got to try out my new to me TSL 100  and I am looking forward to trying out some new/different tubes to get the most out of the amp ( also looks like the stock tubes are still in it )
> I do have one funny question on a TSL 100 looking from the rear which socket it which
> I am thinking that V1 is the far left ( farthest from the power tubes ) with V2-V4 going left to right, can't seem to find the info anywhere all my other amps have labels of some kind or its listed in the owners manual
> Not Marshall it seems



I am wondering the same thing on my JTM60 Head. I have no idea what slot is V1-V4, or if the power tube locations make any difference. I bought the Head online and the tubes were wrapped up in foam and bubble wrap. I think I was thinking the same, V1-V4 left to right, but I honestly have no clue.


----------



## bwt570

I have my EL34s biased at 60%, plate voltage is 390 and plate current is 38-ish mA. When i turn my 50 watt amp up to volume 10 and hit a chord the plate current readings i get are around 270mA. Is it supposed to be that high? Sorry if this is the wrong place to post this.


----------



## mickeydg5

bwt570 said:


> I have my EL34s biased at 60%, plate voltage is 390 and plate current is 38-ish mA. When i turn my 50 watt amp up to volume 10 and hit a chord the plate current readings i get are around 270mA. Is it supposed to be that high? Sorry if this is the wrong place to post this.


 Short answer, yes.


----------



## TSLDanny

*Tsl100 tube suggestions*

Hi all this is my first post on this forum (new to marshalls) and I've recently bought a tsl100h, whoop whoop. When I opened it up I found the power tubes were mismatched (3 reissue Svetlana and 1 unbranded) and the preamp tubes were a mixture of Marshall ecc83 and other things (no print at all)...
I thought it could do with a full retube and so I've scoured forums and tube sites for something that I would feel would solve my problems but I've got bogged down with all the choice and would like some solid suggestions for power and preamp if possible. I'm willing to try nos tubes as well as cp tubes. I find the amp to be lacking a bit in gain ( I know a tsl lacking in gain!?) And it feels too harsh and would like a warmer more rounded sound that would be nicer to the ears. I've got a budget of about £150 for both power and preamp tubes
Any suggestions would be great!


----------



## Bear R.

Hey TSLDanny..Marty's very good with these amps and knows what sounds best in them.

I have a TSL60. and this is what He recommended..and what I just purchased..

For the Power Tube section is a matched set of TAD EL34B big bottle power tubes..they kick butt..60 bucks..But for a set of 4 will cost around 120.?...For the pre amp stages, I went with the TAD 7025WA for the V1 spot..25.00..and next month im getting the Mullard RI 12ax7 for the V2 spot..23.00 and a set of JJ's ECC83's for V3 and V4 spots..25.00 for the set..but just with what I got so far, the amp sounds great..and i mean great..and this should be pretty close your price range too..maybe a little more..i dont know..but well worth it..

He would also recommend the EH 6CA7 power tubes...but I chose to go with the Tad's....Thank you Marty..

ps..I use the MXR Fullbore Metal on the Clean Channel..i just don't care for the other 2 channels..at least not with my amp anyway...but man, this amp now kicks major butt. esp. with these new tubes..

PS..Thanks Marty for your expertise and recommendations..the amp really came to life..I really Really Love it..i cant wait to get the Mullard RI and JJ's to finish it up..thanks bud...Barry..


----------



## LiveLoud

Hello everybody!

Does anybody here have any experiences with either the New Sensor made Svetlana/Tung-Sol/Mullard EL34 and 6L6 reissues? Looking to retube a friend's Egnater Renegade and my collection of NOS tubes is beginning to dwindle...

On the topic of NOS tubes. What sites are trusted sources for NOS tubes? I've found some =C= and some pre =C= Svet's for prices that seem a little bit too good to be true...

Thanks!


----------



## lordquilton

I don't have experience with those power stage valves you listed, but the TAD EL34B-STR's are well worth a look-

http://www.marshallforum.com/showthread.php?t=59770

Off the top of my head, Brent Jesse has a good name for NOS.
He's probably more expensive than some dealers, but word is his stuff is high quality and legit.


----------



## HogDad59

Sir,

I'm new to this forum (any for that matter) so please excuse any errant posts I may make.

My question: I just acquired a 1981 JCM800 2203 and it has JJ's 12AX7 in the pre and GE 6550A's in the power sections. Is there any creditable way of telling their age.

Thanks for your help....

Steve


----------



## mickeydg5

I am going to go with "not usually".


----------



## MartyStrat54

Some GE power tubes have some codes on the plastic base or on the side of the tube, but it may just be the EIA number (188).

Got any pictures of any codes on the tubes?


----------



## HogDad59

Here's the only pic I have right now. No help I know. One tube has a stamp (93-15) that I've found since stands for the 15th week of 1993. The others just have the 188 EIA number.

I'm only wondering about this because I'm curious as to how "good" they may still be.

Think I may buy a tester.

Thanks for your time and input!

Steve (HogDad59)


----------



## mickeydg5

Nice tubes; vintage 6550. Cannot see enough to even try to find a date.

Those tubes, if not abused, can last a lifetime.


----------



## HogDad59

Knowing the guy I got them from, they probably have very few hours on them. He's more of a "collector" of gear than user.
Either way, they sound great right now. I do plan to roll some others through the pre-amp just to find what I like best....
The cab I got is a 1982A (1977) with G12H 30w Blackbacks....diggin' them too.


----------



## MartyStrat54

That's a fine set of GE 6550 metal base tubes. From what I can see the tubes look to be in great shape. The getter flashing is nice and bright. If you are going to play a Marshall with 6550's you can't get much better than these. I don't know what you paid for them, but those are some pricey power tubes. The metal base GE 6550's run around $300 for a matched quad...if you can find a matched quad.


----------



## MartyStrat54

Oh and as far as tube life I would bet money if you tested those tubes they would still be in the 80+ percent range. I bet they still have lots of hours left on them. IIRC GE rated those as 5000 hour tubes if biased correctly.

I bought a 1979 Peavey MACE in 2010 with six Sylvania 6L6GC's that were the original tubes and they all tested 87-88. USA and European power tubes last 3 to 5 times longer than a CP power tube.


----------



## HogDad59

The tubes came with the amp, but I have seen where they are pretty expensive to replace. I simple got lucky on this one.
Long cool story how I came about this set-up but the bottom line is I paid $400.00 for the head and cab. My job is to now make the most of it....


----------



## benoityip

Marty, Great article with a major myth busted !!!

This article should be sticked

That brings so much possibilities after realising power tubes play a smaller role

1. People think marshall Valvestate is a failure because no power tubes are involved. It might sound inferior but definitely not due to so much about the power tubes. I own one of them and they sound great after putting a great preamp tube.

2. Blackstar has preamp tube metal pedal. People thinks most sound coming from solid state inside. Wrong !!

3. We dont need atteunator anymore !!


----------



## G the wildman

Hi Marty

I have new Tad finals in my DSL 40c and they are ok. But I can hear an unwanted chime when I play. I have no idea what causes this. Should I upgrade V1 to help improve this.

If I do upgrade I do not want to lose OD but would like a warmer sound.


Any ideas

G


----------



## EADGBE

MartyStrat54 said:


> ...preamp tubes will make the most change in your tone. Power tubes just add a little.


I can hear a big difference with both.


----------



## YetiVanMarshall

Hello,
DSL40-c . I have been using it on a small stand since new and recently the power tube directly above the speaker is vibrating annoyingly when i play any b chord or b string. I determined this by placing a cooking mitt against it gently against the bottom of the valve and it dampens the vibration. With the amp on the floor I sat on the amp and the vibration does not occur. I'm guessing the tube has become defective since I play loud a lot. I'm thinking about a tube dampner or 2 since the mitt silenced the vibration. Any advice would be greatly appreciated.


----------



## mickeydg5

It seems the vibration is caused by another source but dampers can or will help.


----------



## mtm105




----------



## southbound suarez

Anyone try any of the late model Sylvania 5881 JAN tubes that are starting to appear on the market? I Noticed that these keep popping up on Ebay in small lots and are the black plastic base with green lettering. True NOS in unopened generic white boxed military packaging with black stamped lettering. Great bargains to be found from a few different vendors. Someone must of uncovered or discovered and released a large lot of these somewhere or are being released at some govt. auction? I purchased four unmatched and untested brand spanking new off Ebay for under $90 
I cant wait to test them. Hopefully we have close enough matching for use as a quad, or at the very least get a pair outta the deal. Otherwise its mod a PP amp or SE use. I think these baby bottle beam driven power tubes might be pretty decent in 5881 Marshalls such as JCM 900's or perhaps a Mesa Lonestar. I will let ya guys know , but I am very curious to hear what others have discovered with these tubes. I also have noticed numerous Raytheon 12Ax7's and made a purchase of supposed NOS tubes but looking at condition of the pins and such I doubt true NOS but likely used test as new like they so often describe as being NOS.... These seem pretty quiet and balanced but not real powerhouse. I am happy with how transparent and resilient they are against microphonics. Especially for a long plate.
I also scored two Telefunkens from n old 1959 console high fi. These are original tubes with ribbed grey short plates and they are excellent. I am using one inside of a tweed champ circuit and it is nice!
So what beautiful gems have others scored recently? WHat about those SYL/Jan 5881?


----------



## mickeydg5

Yes I have some. The green lettering came off of the ones I was using over time. They are just as or almost as good as Tungsol. They ran on 470V B+ rail with no problems.


----------



## southbound suarez

Tungsol 5881??? Thats a good thing right? Doh! No experience with the Tungsol. These ones that I got ended up pretty darn closely matched. At least as far as current draw. They certainly are cute little bottles. I bet these would work very nicely to swap out the 6v6's in a fender deluxe reverb.
Here they are being installed in a JCM 900
i have faith that they will work out just fine. Good ol' made in the USA genuine New Old Stock, JAN military surplus from cold war era stocks. 
I just gotta get off my duff , offline and back to the bench,,,, er I meant kitchen table! 

Put a Baldwin by Raytheon blackplate 12ax7 in V1 and a very strong RCA in V3 and left original chinese Marshall in V2 inside this JCM900 4102 ..... Be interesting if there is much noticeable difference.


----------



## mickeydg5

Whoops. When I saw yours I had to think back. You have later 5881 black base, good tubes. The Sylvania I was referencing were my earlier brown base 6L6WGB; the precursor, a substitute and sometimes called 6L6WGB/5881. The green lettering was on the glass.

Oh those tube retainers aint right and will rattle. They should be taut. Those are for larger tubes.


----------



## southbound suarez

Yes, I know, I noticed the tube retainers right away. I simply rotated the spring bracket 90 degree and bent the bracket flat. This took up the slack without shortening or cutting the springs... I also use those silicon dampners that go between the metal retainer and the top of the tube.


----------



## zack603

this maybe a stupid question but he was talking about "rolling" all sorts of different brand tubes and trying different ones...im assuming this is mainly for people who are tone chasing with an amp that they are fairly familiar with, but I have an amp that ive only had for about 5 months and have never changed the tubes and am doing a little research on what tubes I want to try...would it help or hurt my cause to figure out what tubes I want then just buy 4 of the same power tubes and 4 of the same pre amp tubes and put them all in at the same time???


----------



## Micky

zack603 said:


> this maybe a stupid question but he was talking about "rolling" all sorts of different brand tubes and trying different ones...im assuming this is mainly for people who are tone chasing with an amp that they are fairly familiar with, but I have an amp that ive only had for about 5 months and have never changed the tubes and am doing a little research on what tubes I want to try...would it help or hurt my cause to figure out what tubes I want then just buy 4 of the same power tubes and 4 of the same pre amp tubes and put them all in at the same time???


No, it wouldn't hurt. But when buying power tubes, it is important to get a matched quad, and then insure the bias is set correctly after installation.
You can replace preamp tubes one-at-a-time or all at once. No bias required.


----------



## zack603

Micky said:


> No, it wouldn't hurt. But when buying power tubes, it is important to get a matched quad, and then insure the bias is set correctly after installation.
> You can replace preamp tubes one-at-a-time or all at once. No bias required.



ok thank you...this Is my 1st experience with a tube amp and trying to do as much reading as I can an trying to figure out what I want to try is a little mind numbing


----------



## southbound suarez

Just a quick followup, on those sylvania nos 5881's ....
They so far seem to be a very stout and clean tube... very transparent and able to take alot of current too! I haphazzardly ran the plate current up to 49-50 mA for approx 22-24 watts dissapation. The tubes ran hot but barely if any plate glow whatsoever. They did get some saturated creamy goodness but these NOS tubes are too nice for sacrficial tone at no cost type of setup.... we brought em down to a more aporopriate 36mA @ 472V for about a much more reliable and pleasant sounding 17 watts dissapation per tube. 
To really hear the sweetness really requires cranking this amp up to the power tube sweet spot. The preamp in this model amp makes the voicing of the poweramp a bit decieving.... I have bypassed part of the B channel tone circuit and lowered op amp preamp gain to raise input into the tube buffer higher instead, then I run the effects loop with a jumper and run it wide open. This amp is an interesting hybrid with many op amps... I am getting off topic and much has been written on the 900 series. Probably not the best testbed for rolling tubes. But just wanted to mention that if you come across any of these JAN 5881 surplus that are oem late model sylvania, if mine are any indication they are a good bet! I like them and will be looking forward to getting my hands on more as long as I can still find em... Probably the best and only real deal NOS tubes that I have seen in recent days, Made in the USA! Brand new unopened packages, unmatched yet all biased within a just a few 1/10ths of a mA. Outstanding! Very clear and transparent... maybe too transparent, might be better audiophile tube?


----------



## southbound suarez

QUESTION??? or Survey? 
What would be considered a fair price and what is the current price on those holy grail RCA blackplate side getter 6l6GT tubes 
True NOS in the box and price on used test NOS?


----------



## mickeydg5

All you can really do is gauge tube stores, ebay and other sellers to figure high/low pricing. But prices from unreliable sources will not help.


----------



## southbound suarez

True, that does make good sense, and I suppose I asked a question that is difficult to really answer definatively. I suppose there are many variables and that market prices really are all over the board and that it is anyones guess.... In other words, it is likely that I have or can secure my own preferred reputable sources just as well as anyone.... Ebay prices are easily enough accessible and universally accepted to be indicative of current market trends. Seemingly, kinda lame question on my part! Doh!!!! 
Well, yes ! We do all know those to be the High Digit commodity and is like gold or platinum.... Kinda rude to approach a stranger and ask her how much did that diamond ring cost!? But WtF!? Its only rock n roll... so perhaps I shall rephrase this question and bring it into a more topic worthy subject, more interesting that promotes more discussion.... Ok, with that said,
A collectible is only worth as much as whatever the amount you may find someone willing to pay...Right?
(Remember the baseball cards frenzy in the eighties?) 
What would you (anyone) be willing to pay for the NOS tube of your dreams? Such as I find a fascination in the BlackPlate 6L6GC RCA's, of which I think are worth true NOS .... well I dont believe true NOS really exist. So dunno bout true... but I think that nice strong test as new and look clean and minty should be worthy of no more than $200-$225 a matched pair... how realistic am I ? Well if I had a specific application thats the max I would spend... My other Holy Grail is most any of the Telefunken variations of the Diamond 12AX7's.... I have paid $40 per tube for strong late 50's vintage used ribbed short plate with 50%-70% of the white lettering flaking off.... I have come along bargains of these tubes and have bought some that were only medium strength and recieved three or four for under $60.... These I doubt any true NOS are really left .. for a minty clean nice strong test as new I could imagine paying $70-$100 however these are probably usually being sold as true NOS in repro boxes for much more. 
Both of my examples I dont believe in true NOS so in my imagination a true NOS would be a rather priceless thing.... 
I very well may have found a source with a very few true NOS RCA but I am skeptical, so not sure what I may be willing to pay, should I get serious about attempting too acquire. The source is indeed reliable and is NOT a electronic vendor that specializes or provides to the AUDIO market segment.


----------



## aussiebluesville

hi, can anyone tell me if using this tube will harm amp ? 
*JJ 12DW7 / ECC832 Vacuum Tube in v2 of a dsl 401 combo
looking to tame the distortion a little on od1 and od2*


----------



## Matt_Krush

aussiebluesville said:


> hi, can anyone tell me if using this tube will harm amp ?
> *JJ 12DW7 / ECC832 Vacuum Tube in v2 of a dsl 401 combo
> looking to tame the distortion a little on od1 and od2*



It shouldn't...but with that gain difference, it may be difficult to compensate for volume differences between the channels..
Try it and do a review. I am interested in this as well.


----------



## EndGame00

aussiebluesville said:


> hi, can anyone tell me if using this tube will harm amp ?
> *JJ 12DW7 / ECC832 Vacuum Tube in v2 of a dsl 401 combo
> looking to tame the distortion a little on od1 and od2*


 You can try a 5751 preamp tube.


----------



## paul-e-mann

I cant post the chart picture but here's how preamp tubes measure up:

12AX7 - gain factor 100
5751 - gain factor 70
12AT7 - gain factor 60
12AY7 - gain factor 45
12AV7 - gain factor 41
12AU7 - gain factor 19


----------



## Riffraff

I picked up a Bogen M330 a few weeks ago to do a conversion to and found these beauties sitting under the tube shields.


----------



## mickeydg5

Nice tubes.
What are the codes on them?


----------



## Coronado

Riffraff said:


> I picked up a Bogen M330 a few weeks ago to do a conversion to and found these beauties sitting under the tube shields.



HA! That's awesome! Nice score!!!


----------



## Riffraff

mickeydg5 said:


> Nice tubes.
> What are the codes on them?



I haven't bothered to look yet. All of the other Mullards I have are I63 Blackburn tubes.


----------



## BowerR64

Is there anyway to find out what all the numbers mean after the main model of the tube?

Like say 6L6GC or 6L6EH?

I thought they were just like date codes or something but i read something that makes me thing they are something else.


----------



## mickeydg5

Ha. The meanings vary unless you know history.

The EH is Electro Harmonix which means nothing except that they manufactured the 6L6.

A GC however is a historical design designation. The GC was the last 6L6 design with the only post design being military 7581 types.

The 6L6EH is a copy of a Russian design and is no RCA 6L6GC black plate although they claim it to be similar.


----------



## Riffraff

Riffraff said:


> I haven't bothered to look yet. All of the other Mullards I have are I63 Blackburn tubes.



One is etched B0H and the other two are etched B0I.


----------



## GIBSON67

Riffraff said:


> One is etched B0H and the other two are etched B0I.


 

1960 so those should be I61's.


----------



## Riffraff

Cool, That's what I was hoping they would be.


----------



## southbound suarez

What makes them cool is the fact that you dig the way that they sound! Of course, other factors can influence your judgement , such as brand, demand and popularity, price paid and current elitist statistical trends!
I know I have found myself influenced by similiar mass hysteria.....


----------



## kev67

Just found these tests interesting...

https://www.watfordvalves.com/reports.asp


----------



## Raiders757

Maybe this isn't the right place to ask, and sorry if it is, but what little I have read in this thread is very informative.

I've been playing guitar since 1980 (other than the recent five year hiatus I just came off of), and have always been a solid state guy. Having spent the past few months banging the rust off, I decided to buy my first tube amp. I figured instead of buying a tube head for my 4x12, that I would start with an upgrade over the little practice amp I had been using, so I got a used Haze 40. It sounds great, but I have noticed a few issues, being that it's used. I figured I would start with a tube upgrade. 

I've been looking at this kit to get me started. https://www.amazon.com/dp/B00VAK94C...TF8&colid=1GK997VSOPCJ1&coliid=I3QEDG8PJZGGWG

...also this one. https://www.amazon.com/dp/B015YJ4P6...TF8&colid=1GK997VSOPCJ1&coliid=I2Y2BJJ9GOU6FA

...and this one as well. https://www.amazon.com/dp/B00VH5DYS...TF8&colid=1GK997VSOPCJ1&coliid=I3S34DQ0TH1J1P

I am just curious, which set you guys would recommend. it feels very strange being a N00B at something when it comes to guitars and amps, but like I said, tube amps are an entirely new ballgame for me

Thanks to anyone who can help me, and sorry, if this was the wrong place to post this. I just figured this is a subject that gets asked often, and this board might not need another thread asking the same. Cheers!


----------



## mickeydg5

Hopefully some Haze guys will comment.

Try these threads too if you have not seen them.
http://www.marshallforum.com/threads/haze-combo-mhz40c-bias.8288/
http://www.marshallforum.com/threads/marshall-haze-40-mods-and-tube-changes.23028/
http://www.marshallforum.com/threads/does-anyone-know-about-mods-for-the-haze.14227/


----------



## Raiders757

Thank for the quick response. I'll go read the threads you linked and see if they help. \m/ \m/


----------



## Riffraff

Major score the other day....











One of the best sounding EL34's ever made. I picked up this used pair fully tested with >80% life left in them for my Plexi modded YBA-1. 





The faded Amperex Bugle Boy logo.


----------



## mickeydg5

That is nice.

Let us know how they bias up and sound.


----------



## BadgerO

Buying tubes is good practice in my opinion, keeps the supply flowing. I stockpile other components as well.


----------



## Joe6BG6GA

MartyStrat54 said:


> Hello MF members. As we all know, there are always a lot of threads pertaining to tubes. I would like to just share a few things and I hope it will be helpful.
> 
> First off, a lot of questions are directed at the "high gain" Marshall's like a DSL, TSL or 410. Please be aware that these amps get all of their tone out of the preamp stage. I cringe when I hear someone with a DSL asking how they can get "better power tube distortion?" If you have a DSL and the power tubes are distorting, I don't think you will like what you hear.
> 
> DSL amps (and other high gain Marshall's) use four (or more) preamp tubes. V1 and V2 are the gain stages. V3 (A and B) are the Tone Stack and Cathode Follower. V4 is the Phase Inverter tube for the power tube section.
> 
> V1 will make the most noticeable difference in tone and gain. I always say that you want to put your very best tube in V1. The DSL can handle a pretty hot 12AX7 without farting out. I used to be a little conservative about the V1 tube I used, but over the past year, I tend to go with a hotter tube if it fits the player's needs. I use a more moderate tube for those whose playing style dictates it.
> 
> Note: In Plexi's, JMP's and JCM 2203/04's, V1 is the main tube for gain. Half of V2 needs to be considered as well, so I still recommend a good tube for V2.
> 
> Here is something that has me perplexed. Current production tubes are not that expensive. I think any guitarist that has more than two years playing under their belt needs to have a nice stash of tubes to fall back on and also to experiment with for tone. I think every player should have a budget that allows for multiple 12AX7 tubes. They shouldn't be purchased "as needed." I have said this before, "Every tube amp player should have a complete set of tubes to be used for backup purposes or troubleshooting."
> 
> If you own a Marshall or other tube amp and you are running old tubes, because you can't afford a new set, you run the risk of damaging your amp. If you are lucky, a fuse will pop when a power tube blows. However, I have seen more serious damage such as fried valve sockets and burned components. Again, all tube amp owners should have a complete backup set of tubes.
> 
> Now back to 12AX7's. You should try and get yourself a JJ ECC83 (same as a 12AX7). Also, a Tung-Sol and a Mullard RI. You can round out your set with a Shuguang (Chinese) 12AX7. The Shuguang's are usually loved because they are high gain and are a favorite with metal players where a good clean isn't a must.
> 
> Most of the guys I hang with have 30 to 40 12AX7's. Enough to last them for a good long while. Most of these tubes were bought over a three year period. Most of these tubes are NOS. However, I won't go into that, because most of you use current production (CP) tubes. I think a good player would have two each of the preamp tubes I have listed. Having some Electro-Harmonix tubes handy would be good also. The EH tubes can be used as an economical replacement for V3 and V4 (especially the PI tube).
> 
> To "roll" tubes in a high gain amp, you want to have V3 and V4 selected. Therefore, take a couple of EH's and put them in those slots. Put a Mullard RI in V2 and then roll the JJ, the Tung-Sol, Shuguang and even another Mullard in V1. Once you find the one you like, pull V2 and roll your tubes in V2. Once you find the tube you like, then you have your V1 through V4 selected. If you want to get picky, try rolling V3 and then V4. You might notice a very slight difference in tone by rolling these slots. My friends and I like to run a lopsided, high gain tube in the PI. This is because the power section is asymmetrical by nature and a lopsided PI tube will help enhance this. An amp with an asymmetrical signal has a lot of even order harmonics and this is what you want. This goes against what EURO TUBES states. They push their customers towards a "balanced" PI tube. Trust me, you don't need this. I will say that there is a small difference in tone between a lopsided tube and a regular one, but if you are used to rolling tubes, you will hear a small difference.
> 
> Power tubes tend to sound similar to each other when they are cranked. I run NOS power tubes and CP as well. A while back I did a review on how Sylvania Fat Boy 6CA7's (same as an EL34) compared against EH 6CA7's. At lower to moderate volumes, the NOS were better, but going above 5 on the Master Volume they both started sounding very close. I will say that there are some cheap power tubes that are thin sounding no matter what the volume level. I bring this up, because power tubes in high gain amps are designed to be ran "clean." If you use a cheap power tube, you will notice it regardless of the volume level. Look for a well made tube that are frequently recommended. Stay away from the el cheapo tubes. It's just not worth the heartache it will cause.
> 
> In closing, preamp tubes will make the most change in your tone. Power tubes just add a little. You should own a complete backup set of tubes for your amp. You should know that V1 is the most important preamp tube. For the best sound you can get out of your amp, V1 should be tested for microphonics. You'll want V1 to be as quiet as possible. Some tube companies charge $2 to test for microphonics and high gain. This is well worth the price for a V1 tube.
> 
> Remember, asking about which CP tube is best should be answered by YOU. Buy some and try them. I had a customer recently tell me that he had some power tubes that didn't sound right to him. However, he swapped V1 and the power tubes kicked butt. Tubes that sound good in a 2203 may not sound as good in a DSL. You are limited to the tones you can get with CP tubes. (Yes, NOS tubes offer more tone shaping compared to CP.)
> 
> For the most part, rolling tubes is like the icing on the cake. If you are happy with your amps general tone, the speakers you use and the guitar/pickups that you use, then rolling tubes is like the final piece of the tone puzzle.
> 
> I hope that you found this to be of some help.


Greetings to all In regard to Marshall Majors, I recommend Sylvania 12AU7WB for the driver, before the KT88s. Have ran across several Majors with 12AT7s here; not good. This is a low impedance driver stage, and the Sylvania tubes will give a good life here. It's good to be back on the Forum..so far I'm still cancer free


----------



## thescunner

Hi, could you please answer a novice's question regarding valves positions on my 1999 dsl 100 head? I've read so much on this forum about dsl amps and all very informative but how do I identify the V1,V2 sockets etc? Would I be right in assuming it's left to right when viewed from the rear of the amp? Obviously I don't want to any damage when experimenting with new valves. Regards


----------



## mickeydg5

thescunner said:


> Hi, could you please answer a novice's question regarding valves positions on my 1999 dsl 100 head? I've read so much on this forum about dsl amps and all very informative but how do I identify the V1,V2 sockets etc? Would I be right in assuming it's left to right when viewed from the rear of the amp? Obviously I don't want to any damage when experimenting with new valves. Regards


Hello Scunner.
Have a look.
http://www.marshallforum.com/threads/dsl-100-head-preamp-tube-layout.11370/


----------



## thescunner

Hey, thank you for the response and the info, I guess the a & b refer to the channel the tube will affect? Regards


----------



## Dogs of Doom

thescunner said:


> Hey, thank you for the response and the info, I guess the a & b refer to the channel the tube will affect? Regards


most pre-amp tubes are a dual-triode. That means that there are 2- triode tube sets in a single tube. Just like a dual monoblock amp, each triode is independent of each other. So, in an amp, they will sometimes specify what each ½ is doing. so, on V1 (valve 1), each ½ will be indicated as a/b. a, being the 1st triode & b, being the 2nd triode.


----------



## thescunner

Thanks guys, makes perfect sense now.


----------



## thescunner

Hi, I wonder if any of you guys are using JJ EL34L tubes in a dsl 100? If so, are you biasing to the Marshall spec 90 mv?


----------



## Richard Martin

MartyStrat54 said:


> Hello MF members. As we all know, there are always a lot of threads pertaining to tubes. I would like to just share a few things and I hope it will be helpful.
> 
> First off, a lot of questions are directed at the "high gain" Marshall's like a DSL, TSL or 410. Please be aware that these amps get all of their tone out of the preamp stage. I cringe when I hear someone with a DSL asking how they can get "better power tube distortion?" If you have a DSL and the power tubes are distorting, I don't think you will like what you hear.
> 
> DSL amps (and other high gain Marshall's) use four (or more) preamp tubes. V1 and V2 are the gain stages. V3 (A and B) are the Tone Stack and Cathode Follower. V4 is the Phase Inverter tube for the power tube section.
> 
> V1 will make the most noticeable difference in tone and gain. I always say that you want to put your very best tube in V1. The DSL can handle a pretty hot 12AX7 without farting out. I used to be a little conservative about the V1 tube I used, but over the past year, I tend to go with a hotter tube if it fits the player's needs. I use a more moderate tube for those whose playing style dictates it.
> 
> Note: In Plexi's, JMP's and JCM 2203/04's, V1 is the main tube for gain. Half of V2 needs to be considered as well, so I still recommend a good tube for V2.
> 
> Here is something that has me perplexed. Current production tubes are not that expensive. I think any guitarist that has more than two years playing under their belt needs to have a nice stash of tubes to fall back on and also to experiment with for tone. I think every player should have a budget that allows for multiple 12AX7 tubes. They shouldn't be purchased "as needed." I have said this before, "Every tube amp player should have a complete set of tubes to be used for backup purposes or troubleshooting."
> 
> If you own a Marshall or other tube amp and you are running old tubes, because you can't afford a new set, you run the risk of damaging your amp. If you are lucky, a fuse will pop when a power tube blows. However, I have seen more serious damage such as fried valve sockets and burned components. Again, all tube amp owners should have a complete backup set of tubes.
> 
> Now back to 12AX7's. You should try and get yourself a JJ ECC83 (same as a 12AX7). Also, a Tung-Sol and a Mullard RI. You can round out your set with a Shuguang (Chinese) 12AX7. The Shuguang's are usually loved because they are high gain and are a favorite with metal players where a good clean isn't a must.
> 
> Most of the guys I hang with have 30 to 40 12AX7's. Enough to last them for a good long while. Most of these tubes were bought over a three year period. Most of these tubes are NOS. However, I won't go into that, because most of you use current production (CP) tubes. I think a good player would have two each of the preamp tubes I have listed. Having some Electro-Harmonix tubes handy would be good also. The EH tubes can be used as an economical replacement for V3 and V4 (especially the PI tube).
> 
> To "roll" tubes in a high gain amp, you want to have V3 and V4 selected. Therefore, take a couple of EH's and put them in those slots. Put a Mullard RI in V2 and then roll the JJ, the Tung-Sol, Shuguang and even another Mullard in V1. Once you find the one you like, pull V2 and roll your tubes in V2. Once you find the tube you like, then you have your V1 through V4 selected. If you want to get picky, try rolling V3 and then V4. You might notice a very slight difference in tone by rolling these slots. My friends and I like to run a lopsided, high gain tube in the PI. This is because the power section is asymmetrical by nature and a lopsided PI tube will help enhance this. An amp with an asymmetrical signal has a lot of even order harmonics and this is what you want. This goes against what EURO TUBES states. They push their customers towards a "balanced" PI tube. Trust me, you don't need this. I will say that there is a small difference in tone between a lopsided tube and a regular one, but if you are used to rolling tubes, you will hear a small difference.
> 
> Power tubes tend to sound similar to each other when they are cranked. I run NOS power tubes and CP as well. A while back I did a review on how Sylvania Fat Boy 6CA7's (same as an EL34) compared against EH 6CA7's. At lower to moderate volumes, the NOS were better, but going above 5 on the Master Volume they both started sounding very close. I will say that there are some cheap power tubes that are thin sounding no matter what the volume level. I bring this up, because power tubes in high gain amps are designed to be ran "clean." If you use a cheap power tube, you will notice it regardless of the volume level. Look for a well made tube that are frequently recommended. Stay away from the el cheapo tubes. It's just not worth the heartache it will cause.
> 
> In closing, preamp tubes will make the most change in your tone. Power tubes just add a little. You should own a complete backup set of tubes for your amp. You should know that V1 is the most important preamp tube. For the best sound you can get out of your amp, V1 should be tested for microphonics. You'll want V1 to be as quiet as possible. Some tube companies charge $2 to test for microphonics and high gain. This is well worth the price for a V1 tube.
> 
> Remember, asking about which CP tube is best should be answered by YOU. Buy some and try them. I had a customer recently tell me that he had some power tubes that didn't sound right to him. However, he swapped V1 and the power tubes kicked butt. Tubes that sound good in a 2203 may not sound as good in a DSL. You are limited to the tones you can get with CP tubes. (Yes, NOS tubes offer more tone shaping compared to CP.)
> 
> For the most part, rolling tubes is like the icing on the cake. If you are happy with your amps general tone, the speakers you use and the guitar/pickups that you use, then rolling tubes is like the final piece of the tone puzzle.
> 
> I hope that you found this to be of some help.


Thanks for your advice! Can you tell me, What the voltage for my JVM 410h for the bias should be, I found different levels, one said 70mV for my power tubes or 35 mA per-side. Some else said between 68- and 70 is fine.
I didn't want to change out without knowing what to bias them at. Tomorrow I have to try swapping out preamp tubes to see if I have a bad one? Have no output sound from my 1960 lead cab. Only when I plug my guitar into the FX-loop. Hope it's just a tube. Everything looks in mint condition, it's build was 2016. I got it from music dealer, it was a floor model. They said it had harldly been used, but I only put may 20-30 hours on it, in my home when it started acting up. So I purchased all new EL34 tubes and 2 new jjecc 83 tubes. Liked your post. Take care Rich Martin


----------



## Richard Martin

BluesRocker said:


> Great read Marty!
> 
> Thanks for the info!


Hi, hope you don't mind, had another question for you! I like the southern rock sound, like dicky Betts, that almanbrothers sound blues. My JVM 410h is stock, still fairly new. What do you think of those mod changes. I herd they can make your Marshall sound much better? I have no idea. I am a old timer from the 70's. Just started playing again after many years, not being able. I'm not a follower of medle sound. I like high gain, but not to much, I love hearing every note, and love long sastain! Thank you again.


----------



## SkidFx

NewReligion said:


> Great read, thanks. I've been fine tuning my amps this way for years but never really thought about sharing the data. Well done.
> 
> David


Sweet track!!


----------



## HAMPAMP TUBE AMP SERVICES

That is a real fine article Marty my friend but I have to say that my survival kit is an extra head or two and a spare cabinet, damn, need to consider a spare effects board too. All kidding aside, great information, I need to try some of these CP pre tubes, I buy them for customers but have never used a new production preamp tube for personal use since the early 80's. Power tubes are the exception to the rule here though.


----------



## Grogshla

Is it easy to roll your pre amp tubes? I am a complete novice when it comes to electronics. I would like to try a few different combinations and see which one I like the best. 
Any advice would be appreciated.


----------



## nevermind

MartyStrat54 said:


> My friends and I like to run a lopsided, high gain tube in the PI. This is because the power section is asymmetrical by nature and a lopsided PI tube will help enhance this. An amp with an asymmetrical signal has a lot of even order harmonics and this is what you want. This goes against what EURO TUBES states. They push their customers towards a "balanced" PI tube. Trust me, you don't need this. I will say that there is a small difference in tone between a lopsided tube and a regular one, but if you are used to rolling tubes, you will hear a small difference.



I didn't read all the posts, can a kind soul tell me if MS mentions any specific brand/model for this lopsided PI tubes reference?


----------



## nevermind

Grogshla said:


> Is it easy to roll your pre amp tubes? I am a complete novice when it comes to electronics. I would like to try a few different combinations and see which one I like the best.
> Any advice would be appreciated.



Yes, too easy. Once you get the hang of pulling and inserting tubes correctly and without bending pins and cracking bakelite, you will find yourself swapping so much it will drive you towards the brink of insanity... YMMV of course!


----------



## mickeydg5

He is reffering to the 12DW7/7247/ECC832 and ECC823(reversed) type tubes.

They are a 12AX7 and 12AU7 in one bottle.


----------



## Joe6BG6GA

MartyStrat54 said:


> Hello MF members. As we all know, there are always a lot of threads pertaining to tubes. I would like to just share a few things and I hope it will be helpful.
> 
> First off, a lot of questions are directed at the "high gain" Marshall's like a DSL, TSL or 410. Please be aware that these amps get all of their tone out of the preamp stage. I cringe when I hear someone with a DSL asking how they can get "better power tube distortion?" If you have a DSL and the power tubes are distorting, I don't think you will like what you hear.
> 
> DSL amps (and other high gain Marshall's) use four (or more) preamp tubes. V1 and V2 are the gain stages. V3 (A and B) are the Tone Stack and Cathode Follower. V4 is the Phase Inverter tube for the power tube section.
> 
> V1 will make the most noticeable difference in tone and gain. I always say that you want to put your very best tube in V1. The DSL can handle a pretty hot 12AX7 without farting out. I used to be a little conservative about the V1 tube I used, but over the past year, I tend to go with a hotter tube if it fits the player's needs. I use a more moderate tube for those whose playing style dictates it.
> 
> Note: In Plexi's, JMP's and JCM 2203/04's, V1 is the main tube for gain. Half of V2 needs to be considered as well, so I still recommend a good tube for V2.
> 
> Here is something that has me perplexed. Current production tubes are not that expensive. I think any guitarist that has more than two years playing under their belt needs to have a nice stash of tubes to fall back on and also to experiment with for tone. I think every player should have a budget that allows for multiple 12AX7 tubes. They shouldn't be purchased "as needed." I have said this before, "Every tube amp player should have a complete set of tubes to be used for backup purposes or troubleshooting."
> 
> If you own a Marshall or other tube amp and you are running old tubes, because you can't afford a new set, you run the risk of damaging your amp. If you are lucky, a fuse will pop when a power tube blows. However, I have seen more serious damage such as fried valve sockets and burned components. Again, all tube amp owners should have a complete backup set of tubes.
> 
> Now back to 12AX7's. You should try and get yourself a JJ ECC83 (same as a 12AX7). Also, a Tung-Sol and a Mullard RI. You can round out your set with a Shuguang (Chinese) 12AX7. The Shuguang's are usually loved because they are high gain and are a favorite with metal players where a good clean isn't a must.
> 
> Most of the guys I hang with have 30 to 40 12AX7's. Enough to last them for a good long while. Most of these tubes were bought over a three year period. Most of these tubes are NOS. However, I won't go into that, because most of you use current production (CP) tubes. I think a good player would have two each of the preamp tubes I have listed. Having some Electro-Harmonix tubes handy would be good also. The EH tubes can be used as an economical replacement for V3 and V4 (especially the PI tube).
> 
> To "roll" tubes in a high gain amp, you want to have V3 and V4 selected. Therefore, take a couple of EH's and put them in those slots. Put a Mullard RI in V2 and then roll the JJ, the Tung-Sol, Shuguang and even another Mullard in V1. Once you find the one you like, pull V2 and roll your tubes in V2. Once you find the tube you like, then you have your V1 through V4 selected. If you want to get picky, try rolling V3 and then V4. You might notice a very slight difference in tone by rolling these slots. My friends and I like to run a lopsided, high gain tube in the PI. This is because the power section is asymmetrical by nature and a lopsided PI tube will help enhance this. An amp with an asymmetrical signal has a lot of even order harmonics and this is what you want. This goes against what EURO TUBES states. They push their customers towards a "balanced" PI tube. Trust me, you don't need this. I will say that there is a small difference in tone between a lopsided tube and a regular one, but if you are used to rolling tubes, you will hear a small difference.
> 
> Power tubes tend to sound similar to each other when they are cranked. I run NOS power tubes and CP as well. A while back I did a review on how Sylvania Fat Boy 6CA7's (same as an EL34) compared against EH 6CA7's. At lower to moderate volumes, the NOS were better, but going above 5 on the Master Volume they both started sounding very close. I will say that there are some cheap power tubes that are thin sounding no matter what the volume level. I bring this up, because power tubes in high gain amps are designed to be ran "clean." If you use a cheap power tube, you will notice it regardless of the volume level. Look for a well made tube that are frequently recommended. Stay away from the el cheapo tubes. It's just not worth the heartache it will cause.
> 
> In closing, preamp tubes will make the most change in your tone. Power tubes just add a little. You should own a complete backup set of tubes for your amp. You should know that V1 is the most important preamp tube. For the best sound you can get out of your amp, V1 should be tested for microphonics. You'll want V1 to be as quiet as possible. Some tube companies charge $2 to test for microphonics and high gain. This is well worth the price for a V1 tube.
> 
> Remember, asking about which CP tube is best should be answered by YOU. Buy some and try them. I had a customer recently tell me that he had some power tubes that didn't sound right to him. However, he swapped V1 and the power tubes kicked butt. Tubes that sound good in a 2203 may not sound as good in a DSL. You are limited to the tones you can get with CP tubes. (Yes, NOS tubes offer more tone shaping compared to CP.)
> 
> For the most part, rolling tubes is like the icing on the cake. If you are happy with your amps general tone, the speakers you use and the guitar/pickups that you use, then rolling tubes is like the final piece of the tone puzzle.
> 
> I hope that you found this to be of some help.




Greetings! Great advice! A good article Joe6BG6GA


----------



## bordonbert

Hmmm! Interesting reading on a controvesial topic. Have a look here: https://www.amplifiedparts.com/tech-articles/12ax7-comparison-current-made-tubes These guys prove the truth about different valve sounds. Of course, they sell them for a living and they also don't mind absolutely blatantly frigging the results into a series of pretty coloured but meaningless bar charts to confuse the unwary once they get them, but if you ignore the pretty pictures and coloured chaff and look at their very last graph on the page, the one of each tube frequency response laid onto a single plot, you will see the real difference. Their engineering is sound and you can read the truth from it, their interpretation of the results is disgraceful.


----------



## MarshallDog

bordonbert said:


> Hmmm! Interesting reading on a controvesial topic. Have a look here: https://www.amplifiedparts.com/tech-articles/12ax7-comparison-current-made-tubes These guys prove the truth about different valve sounds. Of course, they sell them for a living and they also don't mind absolutely blatantly frigging the results into a series of pretty coloured but meaningless bar charts to confuse the unwary once they get them, but if you ignore the pretty pictures and coloured chaff and look at their very last graph on the page, the one of each tube frequency response laid onto a single plot, you will see the real difference. Their engineering is sound and you can read the truth from it, their interpretation of the results is disgraceful.



Interesting read. Not sure if I agree with their tube tone descriptions because I have a majority of these tubes and my ears and or amp all seem to react with a tone slightly different than they describe. It’s the same old deal, buy them and try them for yourself!


----------



## mickeydg5

At the end of the day what is wanted is a tube that compliments your amplifier and gear whether you need more low, mid or high frequency. The strongest ones are always the best (higher dB level).

Our ears are vastly more sensitive to midrange. Notice the scoop in the midrange and how it works for humans.


----------



## bordonbert

Sorry guys, in trying to be non-confrontational (if a little mildly sarcastic ) I made myself so subtle the point seems to have gone over everyone's head, maybe even including mine. Actually, what I meant was that if you look at that last graph and ignore the artificially created meaningless nonsense that is the individual descriptions and barcharts to sell the types you will see that, in fact, every one of those valves has exactly the same frequency response down to a small fraction of a dB. The point I was trying to suggest without stepping on the toes of the believers is that, if you get back to sound engineering, even though they were trying to prove there were differences, you can see that there is no real difference between valve type frequency responses at all. The only difference is a maximum of a couple of dB of gain which you can clearly see in the spread. Most of the types are within about 1dB of that too. All of that is usual in the component population from even just a single maker.

EDIT: Oh, and the mid range scoop is there because the valves are being tested within a Fender preamp circuit. I don't think it suggests that the valve has a curve like that at all.


----------



## mickeydg5

bordonbert said:


> Sorry guys, in trying to be non-confrontational (if a little mildly sarcastic ) I made myself so subtle the point seems to have gone over everyone's head, maybe even including mine. Actually, what I meant was that if you look at that last graph and ignore the artificially created meaningless nonsense that is the individual descriptions and barcharts to sell the types you will see that, in fact, every one of those valves has exactly the same frequency response down to a small fraction of a dB. The point I was trying to suggest without stepping on the toes of the believers is that, if you get back to sound engineering, even though they were trying to prove there were differences, you can see that there is no real difference between valve type frequency responses at all. The only difference is a maximum of a couple of dB of gain which you can clearly see in the spread. Most of the types are within about 1dB of that too. All of that is usual in the component population from even just a single maker.
> 
> EDIT: Oh, and the mid range scoop is there because the valves are being tested within a Fender preamp circuit. I don't think it suggests that the valve has a curve like that at all.


I was wondering if you would pick up on that and comment. 
Yes the curve(s) do look familiar, do they not?

Still a stronger tube gives people more of what they want. Strength means something when it comes to bass, midrange clarity and chime.


----------



## shredhell

Great Info there, Thank You. Im going to be replacing the stock EH 12ax7 tubes in my mode four, looking at either russian made EH, or JJ ecc83 - or JJ ec803s high performance..Marty do you have any advice or recommendations?


----------



## Dogs of Doom

mickeydg5 said:


> I was wondering if you would pick up on that and comment.
> Yes the curve(s) do look familiar, do they not?
> 
> Still a stronger tube gives people more of what they want. Strength means something when it comes to bass, midrange clarity and chime.


volume, in it's self gives a different perceived tonal balance...

then we can discuss psychoacoustics, where people can hear stuff that's not there...

But, perception by the end user is (almost) everything. If you don't perceive it, it doesn't exist (to you).


----------



## Lukas

MartyStrat54 said:


> Hello MF members. As we all know, there are always a lot of threads pertaining to tubes. I would like to just share a few things and I hope it will be helpful.
> 
> First off, a lot of questions are directed at the "high gain" Marshall's like a DSL, TSL or 410. Please be aware that these amps get all of their tone out of the preamp stage. I cringe when I hear someone with a DSL asking how they can get "better power tube distortion?" If you have a DSL and the power tubes are distorting, I don't think you will like what you hear.
> 
> DSL amps (and other high gain Marshall's) use four (or more) preamp tubes. V1 and V2 are the gain stages. V3 (A and B) are the Tone Stack and Cathode Follower. V4 is the Phase Inverter tube for the power tube section.
> 
> V1 will make the most noticeable difference in tone and gain. I always say that you want to put your very best tube in V1. The DSL can handle a pretty hot 12AX7 without farting out. I used to be a little conservative about the V1 tube I used, but over the past year, I tend to go with a hotter tube if it fits the player's needs. I use a more moderate tube for those whose playing style dictates it.
> 
> Note: In Plexi's, JMP's and JCM 2203/04's, V1 is the main tube for gain. Half of V2 needs to be considered as well, so I still recommend a good tube for V2.
> 
> Here is something that has me perplexed. Current production tubes are not that expensive. I think any guitarist that has more than two years playing under their belt needs to have a nice stash of tubes to fall back on and also to experiment with for tone. I think every player should have a budget that allows for multiple 12AX7 tubes. They shouldn't be purchased "as needed." I have said this before, "Every tube amp player should have a complete set of tubes to be used for backup purposes or troubleshooting."
> 
> If you own a Marshall or other tube amp and you are running old tubes, because you can't afford a new set, you run the risk of damaging your amp. If you are lucky, a fuse will pop when a power tube blows. However, I have seen more serious damage such as fried valve sockets and burned components. Again, all tube amp owners should have a complete backup set of tubes.
> 
> Now back to 12AX7's. You should try and get yourself a JJ ECC83 (same as a 12AX7). Also, a Tung-Sol and a Mullard RI. You can round out your set with a Shuguang (Chinese) 12AX7. The Shuguang's are usually loved because they are high gain and are a favorite with metal players where a good clean isn't a must.
> 
> Most of the guys I hang with have 30 to 40 12AX7's. Enough to last them for a good long while. Most of these tubes were bought over a three year period. Most of these tubes are NOS. However, I won't go into that, because most of you use current production (CP) tubes. I think a good player would have two each of the preamp tubes I have listed. Having some Electro-Harmonix tubes handy would be good also. The EH tubes can be used as an economical replacement for V3 and V4 (especially the PI tube).
> 
> To "roll" tubes in a high gain amp, you want to have V3 and V4 selected. Therefore, take a couple of EH's and put them in those slots. Put a Mullard RI in V2 and then roll the JJ, the Tung-Sol, Shuguang and even another Mullard in V1. Once you find the one you like, pull V2 and roll your tubes in V2. Once you find the tube you like, then you have your V1 through V4 selected. If you want to get picky, try rolling V3 and then V4. You might notice a very slight difference in tone by rolling these slots. My friends and I like to run a lopsided, high gain tube in the PI. This is because the power section is asymmetrical by nature and a lopsided PI tube will help enhance this. An amp with an asymmetrical signal has a lot of even order harmonics and this is what you want. This goes against what EURO TUBES states. They push their customers towards a "balanced" PI tube. Trust me, you don't need this. I will say that there is a small difference in tone between a lopsided tube and a regular one, but if you are used to rolling tubes, you will hear a small difference.
> 
> Power tubes tend to sound similar to each other when they are cranked. I run NOS power tubes and CP as well. A while back I did a review on how Sylvania Fat Boy 6CA7's (same as an EL34) compared against EH 6CA7's. At lower to moderate volumes, the NOS were better, but going above 5 on the Master Volume they both started sounding very close. I will say that there are some cheap power tubes that are thin sounding no matter what the volume level. I bring this up, because power tubes in high gain amps are designed to be ran "clean." If you use a cheap power tube, you will notice it regardless of the volume level. Look for a well made tube that are frequently recommended. Stay away from the el cheapo tubes. It's just not worth the heartache it will cause.
> 
> In closing, preamp tubes will make the most change in your tone. Power tubes just add a little. You should own a complete backup set of tubes for your amp. You should know that V1 is the most important preamp tube. For the best sound you can get out of your amp, V1 should be tested for microphonics. You'll want V1 to be as quiet as possible. Some tube companies charge $2 to test for microphonics and high gain. This is well worth the price for a V1 tube.
> 
> Remember, asking about which CP tube is best should be answered by YOU. Buy some and try them. I had a customer recently tell me that he had some power tubes that didn't sound right to him. However, he swapped V1 and the power tubes kicked butt. Tubes that sound good in a 2203 may not sound as good in a DSL. You are limited to the tones you can get with CP tubes. (Yes, NOS tubes offer more tone shaping compared to CP.)
> 
> For the most part, rolling tubes is like the icing on the cake. If you are happy with your amps general tone, the speakers you use and the guitar/pickups that you use, then rolling tubes is like the final piece of the tone puzzle.
> 
> I hope that you found this to be of some help.


So I know this thread and conversation is years old but still being added to obviously. I have tubes in my JVM 210 that are pushing 6 years but still sound great to me. Marty talks about running old tubes being a risk to damaging your amp but when should I change them if they still sound great. I have other amps so this guy doesn’t get played all the time as it’s a full stack aswell and sometimes just to loud for home use. I’m running SVETLANA EL34’s biased to 37mv and V1&2 JJ ECC83’s, V3&4 JJ ECC803’s, V5 JJ ECC83. Hard to tell the hours on the tubes but I’d say at least 200-250hrs and when I do play it I typically push it hard. The stock tubes made it about 3 years before I changed them. Had one channel completely get super quiet so it was a tell tale sign something crapped out. Do Tubes slowly degrade that you don’t notice the difference over time in tone? Or are they just working properly or not? I’d rather not wait till one just gives up the ghost but hard to justify changing them if the amp still sounds killer.


----------



## EndGame00

Bought a pair of TAD el-34, and a couple of genalex 12ax7... Gonna try them on my Plexi clone...


----------



## mickeydg5

Lukas said:


> So I know this thread and conversation is years old but still being added to obviously. I have tubes in my JVM 210 that are pushing 6 years but still sound great to me. Marty talks about running old tubes being a risk to damaging your amp but when should I change them if they still sound great. I have other amps so this guy doesn’t get played all the time as it’s a full stack aswell and sometimes just to loud for home use. I’m running SVETLANA EL34’s biased to 37mv and V1&2 JJ ECC83’s, V3&4 JJ ECC803’s, V5 JJ ECC83. Hard to tell the hours on the tubes but I’d say at least 200-250hrs and when I do play it I typically push it hard. The stock tubes made it about 3 years before I changed them. Had one channel completely get super quiet so it was a tell tale sign something crapped out. Do Tubes slowly degrade that you don’t notice the difference over time in tone? Or are they just working properly or not? I’d rather not wait till one just gives up the ghost but hard to justify changing them if the amp still sounds killer.


Years old and time in use are two totally different things. 250 hours on tubes is not much at all especially if it aint maxed. I have tubes that are 25 years old that sound better than some new from the store tubes.
The terms should be "hours used" or "worn" and not "years old" for tubes. When they are worn enough there will be signs like losses of clarity, top end, bottom end or off-sounding as not in its normal voice.
Of course tubes can fail at any time but maybe more likely as they are more used/worn.


----------



## dna9656

tonefreak said:


> Awesome post Marty... I will be spending quite a lot of spare cash (whats that???) on tubes this summer... it's been over a year since my amps had tubes, and right now it's just got JJ's all through... so it's time to roll some tubes.
> 
> gotta buy some first.


So Marty; 
I'm a long time player but pretty ignorant of tube swapping. I enjoyed your post as far as i could understand it but you use some jargon I'm not familiar with; like the term "roll tubes into..." Also how do i know that a certain tube in a particular socket won't damage my amp? I see there are a LOT of 12AX7s out there with letters at the end of themodel number I know I can look this information up but that still leaves me not knowing what the amp can handle....


----------



## J E H

tubes are a pain in the ass. I have dealt with them for decades. YES, they do sound good, BUT, they are a pain in the ass.


----------



## Sokool

MartyStrat54 said:


> Hello MF members. As we all know, there are always a lot of threads pertaining to tubes. I would like to just share a few things and I hope it will be helpful.
> 
> First off, a lot of questions are directed at the "high gain" Marshall's like a DSL, TSL or 410. Please be aware that these amps get all of their tone out of the preamp stage. I cringe when I hear someone with a DSL asking how they can get "better power tube distortion?" If you have a DSL and the power tubes are distorting, I don't think you will like what you hear.
> 
> DSL amps (and other high gain Marshall's) use four (or more) preamp tubes. V1 and V2 are the gain stages. V3 (A and B) are the Tone Stack and Cathode Follower. V4 is the Phase Inverter tube for the power tube section.
> 
> V1 will make the most noticeable difference in tone and gain. I always say that you want to put your very best tube in V1. The DSL can handle a pretty hot 12AX7 without farting out. I used to be a little conservative about the V1 tube I used, but over the past year, I tend to go with a hotter tube if it fits the player's needs. I use a more moderate tube for those whose playing style dictates it.
> 
> Note: In Plexi's, JMP's and JCM 2203/04's, V1 is the main tube for gain. Half of V2 needs to be considered as well, so I still recommend a good tube for V2.
> 
> Here is something that has me perplexed. Current production tubes are not that expensive. I think any guitarist that has more than two years playing under their belt needs to have a nice stash of tubes to fall back on and also to experiment with for tone. I think every player should have a budget that allows for multiple 12AX7 tubes. They shouldn't be purchased "as needed." I have said this before, "Every tube amp player should have a complete set of tubes to be used for backup purposes or troubleshooting."
> 
> If you own a Marshall or other tube amp and you are running old tubes, because you can't afford a new set, you run the risk of damaging your amp. If you are lucky, a fuse will pop when a power tube blows. However, I have seen more serious damage such as fried valve sockets and burned components. Again, all tube amp owners should have a complete backup set of tubes.
> 
> Now back to 12AX7's. You should try and get yourself a JJ ECC83 (same as a 12AX7). Also, a Tung-Sol and a Mullard RI. You can round out your set with a Shuguang (Chinese) 12AX7. The Shuguang's are usually loved because they are high gain and are a favorite with metal players where a good clean isn't a must.
> 
> Most of the guys I hang with have 30 to 40 12AX7's. Enough to last them for a good long while. Most of these tubes were bought over a three year period. Most of these tubes are NOS. However, I won't go into that, because most of you use current production (CP) tubes. I think a good player would have two each of the preamp tubes I have listed. Having some Electro-Harmonix tubes handy would be good also. The EH tubes can be used as an economical replacement for V3 and V4 (especially the PI tube).
> 
> To "roll" tubes in a high gain amp, you want to have V3 and V4 selected. Therefore, take a couple of EH's and put them in those slots. Put a Mullard RI in V2 and then roll the JJ, the Tung-Sol, Shuguang and even another Mullard in V1. Once you find the one you like, pull V2 and roll your tubes in V2. Once you find the tube you like, then you have your V1 through V4 selected. If you want to get picky, try rolling V3 and then V4. You might notice a very slight difference in tone by rolling these slots. My friends and I like to run a lopsided, high gain tube in the PI. This is because the power section is asymmetrical by nature and a lopsided PI tube will help enhance this. An amp with an asymmetrical signal has a lot of even order harmonics and this is what you want. This goes against what EURO TUBES states. They push their customers towards a "balanced" PI tube. Trust me, you don't need this. I will say that there is a small difference in tone between a lopsided tube and a regular one, but if you are used to rolling tubes, you will hear a small difference.
> 
> Power tubes tend to sound similar to each other when they are cranked. I run NOS power tubes and CP as well. A while back I did a review on how Sylvania Fat Boy 6CA7's (same as an EL34) compared against EH 6CA7's. At lower to moderate volumes, the NOS were better, but going above 5 on the Master Volume they both started sounding very close. I will say that there are some cheap power tubes that are thin sounding no matter what the volume level. I bring this up, because power tubes in high gain amps are designed to be ran "clean." If you use a cheap power tube, you will notice it regardless of the volume level. Look for a well made tube that are frequently recommended. Stay away from the el cheapo tubes. It's just not worth the heartache it will cause.
> 
> In closing, preamp tubes will make the most change in your tone. Power tubes just add a little. You should own a complete backup set of tubes for your amp. You should know that V1 is the most important preamp tube. For the best sound you can get out of your amp, V1 should be tested for microphonics. You'll want V1 to be as quiet as possible. Some tube companies charge $2 to test for microphonics and high gain. This is well worth the price for a V1 tube.
> 
> Remember, asking about which CP tube is best should be answered by YOU. Buy some and try them. I had a customer recently tell me that he had some power tubes that didn't sound right to him. However, he swapped V1 and the power tubes kicked butt. Tubes that sound good in a 2203 may not sound as good in a DSL. You are limited to the tones you can get with CP tubes. (Yes, NOS tubes offer more tone shaping compared to CP.)
> 
> For the most part, rolling tubes is like the icing on the cake. If you are happy with your amps general tone, the speakers you use and the guitar/pickups that you use, then rolling tubes is like the final piece of the tone puzzle.
> 
> I hope that you found this to be of some help.



Excellent! So excellent that I just ordered a set of tubes that you recommended. I had been putting it off, but your words gave me the confidence to move forward. Thank you!


----------



## IOSEPHVS

I run four Mullard RI CV4004 preamp tubes. They are matched and balanced so it doesn't matter which tube is where. I also have a matched pair of Mullard RI EL34s. I start with the master volume at about 7.5/10, and the channel volumes at 0/10, gain on OD channel as low as possible (about 1/20). Then, I bring up the channel volumes for the desired levels up to about 2/10. If I need more volume, I bring up the master. I want as little preamp distortion as possible. Power tube distortion sounds incredible on the JCM600.


----------



## mickeydg5

J E H said:


> tubes are a pain in the ass. I have dealt with them for decades. YES, they do sound good, BUT, they are a pain in the ass.


JEH, kind of like cats.


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## avspecialist

Hi MartyStrat, I read your opening statement from the beginning of this thread and it makes a lot of sense. I have a 2007 Marshall JVM410H and I finally got it sounding great again recently. 

The amp when I got it 11 years ago came with a new set of JJEL34’s, installed by a tech I know very well, who serviced it for Guitar Center before they sold it. He told me the amp had a clean bill of health. I always thought it was a great amp, but as you live and play with any amp, you start to notice holes in the sound character.

I too have read all the forums, a lot from the JVM forum, reading about each persons tube rolls. So I decided to try for my self what changes I can make to my amp. I did start doing some minor modding first, like the Variable negative feedback control and a couple of resistor and cap additions/changes. Those mods did do some magic, but the amp was not exactly to my liking. Basically, a little too bright with some edginess. I have a fair amount of tubes, like NOS Telefunkin, Sylvania, USA Tungsol, RCA and some GE’s. I also have a fair amount of CP like EH, Tunsol,RFT, Sovtek, sungwang, to name a few. 

Basically over a years time, I rolled them every which way, yes it made a difference, but like you stated it was the icing on the cake. I play mostly at home about 5 hours a week on this amp and then after a while I go to one of my other ones and may not play the Marshall for 4 or 5 months and at times up to a year.

Recently I came back to the JVM after about a year or so and I noticed there was a significant lack of bass response, no more low end chug. So I decided to roll an array of tubes and it did make it different but not much better. Then I thought perhaps the bias drifted on the JJ output tubes and that’s why it sounded so thin. When I checked using my meter and my techtronics scope, my sound technology 1701A analyzer and my Weber 200 watt reactive load center, the tubes were a fairly even 70mv per side at 457 plate voltage. I upped the bias to 82 my, and it really didn’t sound any better. The output looked very good on the scope and the bias setting I used had just the slightest notch distortion, which I’m told is good.

So for the heck of it, I pulled out the JJ power tubes and installed a set of The Preferred Series EL34 and scoped it and ended up at 82 mv for the bias. When I turned on the amp to play, I was amazed on the over all extension of the bass response was as well as how much smoother the sound was. Then I went back to the preamp tube roll and swapped out tubes to tweak the tonal balance for the different modes on the JVM. The amp is quit outstanding an all 12 preamp modes.

I’ running a Preferred series in V1, a reissue Millard 12ax7 in V2, a preferred series in V3 a tungsol in v4 and another Preferred Series for the PI. 

I am completely blown away on the frequency response of the amp, it’s quietness and how different each of the 12 modes are. 

To get to the point of this writeup, and I’m sure you know a lot more about tubes than I do, do you think the JJ power tubes was the road block on hearing the preamp tube changes ? Why the sounded fairly decent a while back. I’m guessing the JJ’s have possibly 80 to 100 hours on them. Also from looking at the JJ’s on the scope and still having a good waveform, that in this case , were the JJ’s the limiting factor.?? i’m just curious on your thoughts, thanks


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## mickeydg5

Hmmm, think of tubes as equalizer amplifiers.
Certain tubes emphasize different sound and frequency characteristics more than others due to build.
You want something up front that creates large scale emphasis on what you desire and then power tubes that compliment what you have built thus far.
Strength or gain of every tube is crucial.


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## solarburn

mickeydg5 said:


> Hmmm, think of tubes as equalizer amplifiers.
> Certain tubes emphasize different sound and frequency characteristics more than others due to build.
> You want something up front that creates large scale emphasis on what you desire and then power tubes that compliment what you have built thus far.
> Strength or gain of every tube is crucial.



Yes. Tubes matter. Circuit matters. Choose your tweak. Don't forget speaker EQ. Most important? Play.


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