# KT77 vs. EL34



## LPMarshall hack

I've been reading that these are pretty much interchangeable. Can anyone describe the tone difference between the two tube types? Maybe give an example of an amp or player's tone of each for reference? Thanks!


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## big dooley

tonewise they're somewhere between an EL34 and a 6L6... 
bigger bottom end, nice detailed highs... more headroom too


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## LPMarshall hack

Is there an guitar player or band whose tone is a classic KT77 sound? Just having trouble picturing a KT77 sound vs an EL34 sound. Or is the difference even that drastic?


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## MajorNut1967

Try ManOwar I believe Stillwell has one or more of the guitars running on KT77!


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## PaoloJM

LPMarshall hack said:


> Is there an guitar player or band whose tone is a classic KT77 sound? Just having trouble picturing a KT77 sound vs an EL34 sound. Or is the difference even that drastic?



There are so many variables in any given guitar sound that there is no classic KT77 sound really.

The difference isn't dramatic IMO. 
They work nicely in my JCM800. In wanted a touch more defined lows and a touch more clean power, they did the trick. 
My drummer or singer couldn't hear the difference though.

I ignore the bass players opinion as he's not even concious of when we change the tempo of a song!!


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## LPMarshall hack

PaoloJM said:


> There are so many variables in any given guitar sound that there is no classic KT77 sound really.
> 
> The difference isn't dramatic IMO.
> They work nicely in my JCM800. In wanted a touch more defined lows and a touch more clean power, they did the trick.
> My drummer or singer couldn't hear the difference though.
> 
> I ignore the bass players opinion as he's not even concious of when we change the tempo of a song!!




Thanks Paolo. Is one more "middy" than the other? I like mids!


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## big dooley

LPMarshall hack said:


> Thanks Paolo. Is one more "middy" than the other? I like mids!



that's hard to say... although some people state, the KT77's hollow out the mid's, i don't feel it this way... it's like an EL34 with more bottom end and some nice pronounced highs... but the mids are still there imo


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## RynoAZ

PaoloJM said:


> I ignore the bass players opinion as he's not even concious of when we change the tempo of a song!!



Hahahahahahaha!!!!  Bass players...


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## LPMarshall hack

big dooley said:


> that's hard to say... although some people state, the KT77's hollow out the mid's, i don't feel it this way... it's like an EL34 with more bottom end and some nice pronounced highs... but the mids are still there imo



I may just have to try them out next tube change then. More bottom end...I like that. When you say the KT77's "hollow out the mids", you don't mean a scooped mid sound like in metal do you?


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## big dooley

LPMarshall hack said:


> I may just have to try them out next tube change then. More bottom end...I like that. When you say the KT77's "hollow out the mids", you don't mean a scooped mid sound like in metal do you?



yes that's what i meant... but i don't agree with that statement... the mids are still there... like paoloJM said, the difference is not dramatic, but for the player noticeable
in what amp are you planning to put new tubes in?


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## solarburn

Yeah I agree. The mids are present enough to not be scooped at least in my amp. The clean tones are warmer with the highs being smoother (yet defined) than El34's I've used. They do have a bigger bottom end. Overall I liked them. Having said that mine sit in my tube drawer. I have my preferences.


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## 00jett

I had kt-77 tubes in my dsl for a while. I found them more balenced sounding throughout the mid section and they hard a nice sparkle in the high end. The reason they are no longer in my dsl tho is because of the extended low end. They had alot more low end but i found it, almost boomy and loose sounding. One thing about the el34 low end roll of is that the amp remains tight, so i switched back to el34 tubes. The E34L tubes were better for my ears.


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## LPMarshall hack

big dooley said:


> yes that's what i meant... but i don't agree with that statement... the mids are still there... like paoloJM said, the difference is not dramatic, but for the player noticeable
> in what amp are you planning to put new tubes in?



My amp is a JCM 900 2500. I recently put new tubes in it, so they have a lot of life left. I'm just kicking around ideas for the next tube change. I wouldn't prefer KT77's if they make me sound too metal-ly. I prefer a more classic rock sound (AC/DC, GUNS, Social D, Buckcherry...etc) with not a lot of gain.


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## dbf909

LPMarshall hack said:


> My amp is a JCM 900 2500. I recently put new tubes in it, so they have a lot of life left. I'm just kicking around ideas for the next tube change. I wouldn't prefer KT77's if they make me sound too metal-ly. I prefer a more classic rock sound (AC/DC, GUNS, Social D, Buckcherry...etc) with not a lot of gain.



I run KT77s in my DSL and like them alot. The tone shift (as most have said above) is very subtle. They will not make the amp more "metal-ly" or more "classic rock" sounding. It is just a subtle "rounding" or "filling in" of the tone. I like it - most people, in general, wouldn't be able to tell the difference.


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## LPMarshall hack

dbf909 said:


> I run KT77s in my DSL and like them alot. The tone shift (as most have said above) is very subtle. They will not make the amp more "metal-ly" or more "classic rock" sounding. It is just a subtle "rounding" or "filling in" of the tone. I like it - most people, in general, wouldn't be able to tell the difference.



Thank you...I've got a bit to go before my next tube change, but I'm definately gonna consider them.


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## Darrenw5094

Are JJ the only valve company to make KT77's?


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## dbf909

A quick search reveals that New Sensor is now offering them - Branded "Gold Lion".

The only other brand I have seen is JJ.


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## savant421

So here's my take after demoing both EL34 and KT77 in a Peavey 3120 (fantastic amp btw)

KT77 (JJ) - Smoother highs and mellower lows. Sounds creamy, tame. 

EL34 (Svetlana) - More pronounced, throaty, little more "wild" sounding

TBH, they are both very similar and a couple swipes on the EQ and I could get one to sound like the other. Both are great, just experiment. For instance, I have a Marshall 2203 that doesn't sound right with anything other than EL34s and I have a Splawn QuickRod that benefited from the KT77s. Both tubes sound great in the PV 3120


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## diesect20022000

chuck harmon jr. our old marshall friend uses them now and he plays classic rock, country, jazz. i play them and i play metal,shred, progressive etc.

take the mids of a 34 and the quick THUMP of the lows and add the smoother but strong highes and round lows (yes the lows are a 50/50 hybrid) of a 6l6. to ME they're the BEST of BOTH worlds. a great 34 and 6l6 combo.

they have a more complex midrange than a 34 though and a bit more sting in the upper mids/highs than a 6l6 in a GOOD way. they're a great power tube with good headroom and punch and if you like your tone but want MORE of it they're perfect imo.

the E34L is my backup choice but outside of those i go for ruby most of the time (good tone,rugged and easily replaced if you get a bad set). to me they beat the hell out of winged C's by a LARGE margin in jmp 2203's,4500's,2500's (both 2500's) 2100's, DSL100's, Framus Dragon and Cobra's and TSL 60's. I've used them in others as well like peavey XXX and i still loved them over the rest but in a good Framus or Marshall they're heaven and hell all in one


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## diesect20022000

savant421 said:


> So here's my take after demoing both EL34 and KT77 in a Peavey 3120 (fantastic amp btw)
> 
> KT77 (JJ) - Smoother highs and mellower lows. Sounds creamy, tame.
> 
> EL34 (Svetlana) - More pronounced, throaty, little more "wild" sounding
> 
> TBH, they are both very similar and a couple swipes on the EQ and I could get one to sound like the other. Both are great, just experiment. For instance, I have a Marshall 2203 that doesn't sound right with anything other than EL34s and I have a Splawn QuickRod that benefited from the KT77s. Both tubes sound great in the PV 3120


 i hate svets.....the ass end sounds like someone got the shits and put them in a power tube  SUPER gnarly and non linear.

if you mean the winged C's then those i like but they're way overpriced and under "spiced" imho. they too have a mushy low end though it's a more focused mush not a gnarled flatulance.


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## SmokestackElRopo

If you ask for a description of KT66 tone, it will be described as the same, as the KT77. whatup??


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## ibmorjamn

I wonder how the kt 77 (jj's) will sound in the single recto ?
At least I think I can through them in since it has fixed bias.


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## paul-e-mann

Try them you'll like them better than EL34.


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## mickeydg5

Like described previously they should be similar to the EL34 but with some characteristics of the 6L6 and KT66.


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## shooto

I totally dig KT77s in my JMP...much more so than EL34s...to put it simply, the basic characteristic of the EL34s is that they are mid-driven and not much else, imo...I dig them but one-trick pony

KT77s have a broader spectrum of sound...wider that EL34...kinda scooped, but not really, the mids are there but the tops and bottoms are more present as well...and not like a 6L6...not as pronounced and glassy as those things, but a really nice pronounced frequency spread across the board with KT77s...I'll use this adjective for them although nobody really understands it, but that's how they sound to me..."3D"


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## ibmorjamn

Cool , I will try them. 
Let it Roll , the tubes that is . Lol
I found this quote from Eurotubes

"JJ Electronic KT77
Factory description: Gold plated control grid for improved fidelity. Special plate alloy to improve plate dissipation. This is a hand aligned Beam power tube resulting in stable performance at higher power levels."

"Our observation: The story behind this tube is that it was made by JJ at my request after meeting with them. I quietly sacrificed a pair of my original GEC KT77 for them to test and then break apart (while I wasn't looking) to reverse engineer. The result is a stunning new production KT77 that has all the qualities I coveted in the original. The JJ KT77 has a slightly deeper low end than the JJ E34L and they have a nice sizzle on the top end without getting brittle and the mid range harmonic structure is very complex. The clean tone is very fat and full and the when driven to saturation the crunch has more of a chunk to it. We LOVE these in Marshall DSL's, TSL's and JVM's! (See the retube kits in the online store) We also use a lot of them in Peavey XXX and JSX amps. They are also one of our fave's in Mesa Rectifier amps that can accommodate EL34's if you're after a British sound."


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## ibmorjamn

pedecamp said:


> Try them you'll like them better than EL34.


I have intentions to put them in the Marshall but the Mesa will take either 6L6 or El34. It came with 6L6's and I want to try these out.



mickeydg5 said:


> Like described previously they should be similar to the EL34 but with some characteristics of the 6L6 and KT66.


Should work well in the single rectifier.



shooto said:


> I totally dig KT77s in my JMP...much more so than EL34s...to put it simply, the basic characteristic of the EL34s is that they are mid-driven and not much else, imo...I dig them but one-trick pony
> 
> KT77s have a broader spectrum of sound...wider that EL34...kinda scooped, but not really, the mids are there but the tops and bottoms are more present as well...and not like a 6L6...not as pronounced and glassy as those things, but a really nice pronounced frequency spread across the board with KT77s...I'll use this adjective for them although nobody really understands it, but that's how they sound to me..."3D"


Excellent , going to try them tomorrow.


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## paul-e-mann

Its my observation that KT77 tubes decrease compression, add a more open airy tone and has a bigger bottom end. Its a good tube to make a modern sounding amp sound more classic. So far I've only paired them with JJ preamps so I dont know what compliments them the best yet.


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## chuckharmonjr

I love 77's in my DSL and JMD....but when I tried 'em in my 2204 they sounded like total ass.


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## paul-e-mann

chuckharmonjr said:


> I love 77's in my DSL and JMD....but when I tried 'em in my 2204 they sounded like total ass.



I liked them in my 2204!


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## ricksteruk

I think I will order a set for my 4210. I've got no spare power tubes right now, and the KT77 sound to be just what I'm looking for!


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## DSMer

I have used both Genalex Gold Lion KT77 and JJ's in my DSL40C . JJ's failed on me after two gigs. Genalex has been through five gigs and still rocking. 

They both sound different. Gold Lions is by far way better to my ears. More open, uncompressed tone and gave the amp more headroom.


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## paul-e-mann

The set of JJ KT77's in my DSL are at least a couple years old. No problems.


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## ibmorjamn

Ok, here is the Boogie in Channel 2 Modern with KT77's
It sounds very much like a marshall to me. I love the tone !
I have some other little clips I will put up later but I think my playing is rough still.
http://soundclick.com/share.cfm?id=12795102
http://soundclick.com/share.cfm?id=12795100
This last little off the cuff mess has a little bit of dynamic with just softer playing at the beginning. Horrible notes at the end but the kt77's sound decent.
http://soundclick.com/share.cfm?id=12795108


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## ibmorjamn

TAD 6L6GC-STR 6L6 woo hoo !
https://soundcloud.com/jamn_2006/6l6-td-stlr-052014


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## dslman

May try some 77's in my DSL50 . 
OOPS! Old posts -- but still valid.


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## mickeydg5

Do it!


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## paul-e-mann

Yup I'm still an advocate they are the best tubes in a DSL. JJ pre's too.


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## Bigmuff

I've been wanting to try them in my DSL but I'm afraid MORE bottom end is going to be total overkill. I already have to be careful about not being boomy and blowing out the bassist.

Yeah, I know it's a necropost but we're still on target.


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## diesect20022000

They're awesome in thinner marshalls. They have the mids of a 34 but the treble and bass of a 6l. My favorite but I'm po'.


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## paul-e-mann

Bigmuff said:


> I've been wanting to try them in my DSL but I'm afraid MORE bottom end is going to be total overkill. I already have to be careful about not being boomy and blowing out the bassist.
> 
> Yeah, I know it's a necropost but we're still on target.



Theyre not boomy through a 2x12 that I know, anything else I cant say. I tend to run all my settings at 5 which works well, I dont know what youre doing or if you use a 4x12. I've never heard of a boomy DSL!


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## paul-e-mann

I dont have a DSL any more so I'd be willing to trade my pair of KT77's to anybody that has a pair of TAD EL34B I'd like to try.


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## Bigmuff

pedecamp said:


> Theyre not boomy through a 2x12 that I know, anything else I cant say. I tend to run all my settings at 5 which works well, I dont know what youre doing or if you use a 4x12. I've never heard of a boomy DSL!



I have a 4x12 and a 2x12, both Avatar. The 2x12 is usually ok. The 4x12, which has 2 Greenbacks and 2 V30s, can sound kind of boomy if I push it and have the bass too high. I typically run deep switch in, bass on 0 or 1. However, the boominess I'm detecting is while I've got it way too loud in a small room. I don't use the 4x12 while gigging out often enough to say if it's still booomy in an appropriately sized room. I can carry the 2x12 in one hand, so that's what usually goes to gigs.


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## paul-e-mann

Bigmuff said:


> I have a 4x12 and a 2x12, both Avatar. The 2x12 is usually ok. The 4x12, which has 2 Greenbacks and 2 V30s, can sound kind of boomy if I push it and have the bass too high. I typically run deep switch in, bass on 0 or 1. However, the boominess I'm detecting is while I've got it way too loud in a small room. I don't use the 4x12 while gigging out often enough to say if it's still booomy in an appropriately sized room. I can carry the 2x12 in one hand, so that's what usually goes to gigs.



OK, deep switch that can be boomy. How does it sound with deep off and the rest of the knobs on 5 through the 4x12?


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## MarshallDog

I love them in my Orange MKII Rockerverb, DSL 40C and Marshall 2558 Jubilee. They reduce some of the compression and the tone is much richer to me. I don't like them in my JMP 2204. Like a few other have said, I think they make a newer high gain amp sound more classic...IMO.


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## shooto

I love KT77s...replace all the EL34s with them


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## ampmadscientist

Tubes are all different flavors so, if it really matters you need to try them both.

They both sound pretty good.


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## Jaymz E

I used my Dr Z 6545 with JJ KT77s for the first time at rehearsal last night. The KT77s were in the amp when I got it and they sound really good in this amp, which is kinda like a modded JCM 800 with a Hiwatt channel. I've been wanting to put a pair of =C= EL34s in it, but the KT77s sound good and are working fine so I'll wait until they get tired before I try the =C=s. I used the 6545 with a stock Marshall 1960 angled cab, Maxon 820 over drive pro, EHX SMMH delay and a '82 Gibson LPC / '07 Fender EJ Stratocaster. If my playing was as good last night as the tone I would have been a happy camper.


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## LedZeppelinFan

I perfer KT77's. I believe it was Reinhold Bogner who once described them as being what a EL34 wants to be when it grows up. They take the best bits of the 6L6 and EL34 tonaly, and combine them. They have a big sound. Not much compression at all. When pushed they have a beautiful, harmonically complex breakup. 

They do have some of the characteristics of the others in the KT Family. KT's are generally HiFi tubes, but sound mint in guitar amps. Go listen to Steppin' Out off of John Mayall and the Bluesbreakers with Eric Clapton for a kickass 1960 Les Paul into Marshall Bluesbreaker tone. The Bluesbreaker is KT66. This album inspired Jimmy Page to buy a Les Paul and a Marshall. He liked the sounds Clapton got. That leads me to KT88 tones. Go listen to every live Zeppelin recording you can find. His live tone was driven by his Marshall 1959's modded to run off KT88's. Also, you can have a listen to the Major tones on Deep Purple records. 

For me, KT beats EL every time. I love KT's. Also, note that the different tubes in the KT family do sound very different. They work differently in different amps.


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## LedZeppelinFan

pedecamp said:


> Yup I'm still an advocate they are the best tubes in a DSL. JJ pre's too.



I have one of those Egnater Tweaker amps. I recently got JJ KT77's for the output and JJ ECC803S Gold Pin for the Pre. It lost all that ugly mushiness the stock tubes have gaining a HUGE open sound, and now has more accurate representations of the different voices, with nice cleans, and harmonically complex, creamy breakup. I told the guy at Eurotubes the sound I wanted, and that's what he recommended. It blew me away. 

Sure, my home Plexi got stolen (with KT77's, mind you!) as did my Bluesbreaker, but this is a worthy replacement! I kid you not, this amp is versatile to no end. With that set of tubes, Bruce Egnater could ask $1500 for it, and after playing it, people would fork it over.


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## Chance

LedZeppelinFan said:


> I perfer KT77's. I believe it was Reinhold Bogner who once described them as being what a EL34 wants to be when it grows up. They take the best bits of the 6L6 and EL34 tonaly, and combine them. They have a big sound. Not much compression at all. When pushed they have a beautiful, harmonically complex breakup.
> 
> They do have some of the characteristics of the others in the KT Family. KT's are generally HiFi tubes, but sound mint in guitar amps. Go listen to Steppin' Out off of John Mayall and the Bluesbreakers with Eric Clapton for a kickass 1960 Les Paul into Marshall Bluesbreaker tone. The Bluesbreaker is KT66. This album inspired Jimmy Page to buy a Les Paul and a Marshall. He liked the sounds Clapton got. That leads me to KT88 tones. Go listen to every live Zeppelin recording you can find. His live tone was driven by his Marshall 1959's modded to run off KT88's. Also, you can have a listen to the Major tones on Deep Purple records.
> 
> For me, KT beats EL every time. I love KT's. Also, note that the different tubes in the KT family do sound very different. They work differently in different amps.


So based off your description it sounds like kt77 are tonally very similar to sovtek 5881s? It's a mid forward tube imo but with more bottom end and a bit more full then el34 but not huge bass and glassy like 6l6..... I always thought the sovtek 5881 to be right in the middle of 6l6 and el34.... Never tried kt77s though


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## What?

I have some KT77's on order. Looking forward to trying them out. With EL34's in my 1987 clone (still fairly new to me) I'm noticing quite a bit of compression on hard pick attack, not a ton of headroom, and very prominent mids. I'm hoping that KT77's will change all that a bit.


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## FleshOnGear

I just wanted to add that KT77s are rated for up to 600V on their screens, which should make them theoretically safer in amps with HT over 500V. Maybe I’ll try them in my Traynor. Anybody try the Genalex KT77?


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## Trouble

Now that you guys dragged up a 10 year old thread, the curiosity is killing me. Did @LPMarshall hack actually try these tubes sometime over the last 10 years or did he just pound a bunch of brown bottle beers? 

my money is on the beers


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## Im247frogs

Travis398 said:


> Now that you guys dragged up a 10 year old thread, the curiosity is killing me. Did @LPMarshall hack actually try these tubes sometime over the last 10 years or did he just pound a bunch of brown bottle beers?
> 
> my money is on the beers


Sick burn.


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## LPMarshall hack

Travis398 said:


> Now that you guys dragged up a 10 year old thread, the curiosity is killing me. Did @LPMarshall hack actually try these tubes sometime over the last 10 years or did he just pound a bunch of brown bottle beers?
> 
> my money is on the beers


Havent tried them yet! Been waiting for more replies before I pull the trigger.


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## What?

LPMarshall hack said:


> Havent tried them yet! Been waiting for more replies before I pull the trigger.



You have a point. Not that many replies in over 8 years.


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## LPMarshall hack

What? said:


> You have a point. Not that many replies in over 8 years.


I’ll revisit in 2030


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## Filipe Soares

I have replaced the 34s in my savage with 77s. Very subtle difference. Changing speakers is way more dramatic. The end result was: better bottom end and more clarity in general. But again, very, very subtle.


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## What?

Filipe Soares said:


> I have replaced the 34s in my savage with 77s. Very subtle difference. Changing speakers is way more dramatic. The end result was: better bottom end and more clarity in general. But again, very, very subtle.



Sounds like LPMarshall hack is doing it right then. I'll report back when mine arrive and I have had a chance to do some comparing. I did some preamp tube swapping again yesterday, and I didn't notice any major differences, only subtle ones that I could pretty much adjust away with the amp's controls (1987 clone). I think my next step is trying a big bright cap value of 4700pf on this amp. It has a 3 position switch for 1000pf, none, 100pf. I don't use the center 'none' position so far, so I might as well put it there for comparing.


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## SmokeyDopey

LPMarshall hack said:


> Havent tried them yet! Been waiting for more replies before I pull the trigger.


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## LPMarshall hack

SmokeyDopey said:


>



Alright! Alright!!!


I’ll do it


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## FutureProf88

LPMarshall hack said:


> I've been reading that these are pretty much interchangeable. Can anyone describe the tone difference between the two tube types? Maybe give an example of an amp or player's tone of each for reference? Thanks!



The EL34, 6CA7, and KT77 are electrically interchangeable. 6CA7's are supposed to have a bit more low end grunt. KT77's are supposed to be between an EL34 and 6CA7. To be honest I really can't tell a difference, at least that can't be EQ'd out... And I've found when I roll tubes I tend to make some EQ adjustments anyway, so I guess I just have a way that I *want* the amp to sound and I search for it even if I try a different tube to get a different sound.


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## LPMarshall hack

Ok I’m sticking with the el34s!


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## What?

LPMarshall hack said:


> Ok I’m sticking with the el34s!



I have a set sitting on the kitchen table. Try them, send theem back, or hold onto them for 8 years and then try them?


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## GWWhitehead

Chance said:


> So based off your description it sounds like kt77 are tonally very similar to sovtek 5881s? It's a mid forward tube imo but with more bottom end and a bit more full then el34 but not huge bass and glassy like 6l6..... I always thought the sovtek 5881 to be right in the middle of 6l6 and el34.... Never tried kt77s though


5881s are just mil spec 6L6GC.


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## Joe6BG6GA

LPMarshall hack said:


> I've been reading that these are pretty much interchangeable. Can anyone describe the tone difference between the two tube types? Maybe give an example of an amp or player's tone of each for reference? Thanks!


GreetingsThe KT77 is a beam power tube..with aligned grids..for reduced screen current. This will lower your overall distortion for a cleaner sound. You must rebias amp when using these.


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