Need to replace the valves from my JVM 410HJS?

[hosselausso]

Hi,

I own a Marshall JVM 410HJS with a 1960 cabinet, both bought second hand and at home I normally use the direct output connected to my audio interface. I have the feeling that the amp doesn't sound as it should, with Red channel in OD1 or OD2 it sounds a bit slack, too fuzzy, like not clear at all.. not sure how to explain. Also, the clean-green channel is very silent compared to others.

I'm not an expert in valves, so I have taken pictures of all the valves (excuse the quality) and recorded 2 videos.
Valves:
How it sounds:

Can anyone spot any problem at first glance?

I also have 2 questions.
- What is that valve on the top left which has some sort of lid or cover?
- There are 2 valves without anything printed on the glass. Are those ECC83 too?

 

[crossroadsnyc]

Welcome to the forum, dude. I went ahead and moved to this thread to The Workbench sub-forum for you.

 

[Jethro Rocker]

Gain is way too high in OD modes red!
This is a very gainy amp and higher settings will certainly aound "not clear".
Drop it to maybe 3 or 4. It will sound fizzy and very unclear at full gain.
Green clean bypasses the gain control so volume for that channel should be set according to the level of other channels. If you use Orange or Red mode as well in channel one then use the second master volume to compensate.

 

[Jethro Rocker]

Valve with cover is the first one in the chain and it is covered to reduce RF interference which would then be amplified down the line. The others likely are ECC83 as well but could be 82s etc.

 

[Leonard Neemoil]

The low notes sound really fuzzy whereas the higher notes don't sound too bad.

The gain is set really high for a JVM. Is your string action too low so you don't have the sustain you should so you're compensating by increasing the gain?

 

[Chris-in-LA]

The problem? Having all the knobs at 10 never sounds good.

 

[Jethro Rocker]

I should add, if this is recorded direct out try it micing speaker. Will be a big difference in tone.
Drop the gain and likely some of the high end once through speaker.

 

[Spanngitter]

First of all, that Amp sounds normal but back up that Gain and Volume a tad..
2nd the DI output will ALLWAYS give you fuzzy tone if there is no Amp Sim/IR utilized to record as it plainly taps off the Sound after the PreAmp so no Power Amp and Cabinet involved to shape the sound as you expect it..

 

[AlanHarper]

Hi,

I own a Marshall JVM 410HJS with a 1960 cabinet, both bought second hand and at home I normally use the direct output connected to my audio interface. I have the feeling that the amp doesn't sound as it should, with Red channel in OD1 or OD2 it sounds a bit slack, too fuzzy, like not clear at all.. not sure how to explain. Also, the clean-green channel is very silent compared to others.

I'm not an expert in valves, so I have taken pictures of all the valves (excuse the quality) and recorded 2 videos.
Valves:
How it sounds:

Can anyone spot any problem at first glance?

I also have 2 questions.
- What is that valve on the top left which has some sort of lid or cover?
- There are 2 valves without anything printed on the glass. Are those ECC83 too?

View attachment 107703

All the small valves are ECC83 ( same as 12AX7). As someone else said the can is there to shield the first valve in the chain from any stray interference. You can not tell a valves performace just by looking at them you need them tested to know for sure. IF you were going to replace any without testing - or checking the bias on the output valves which is always a good idea anyway, then try swapping V5 and any of the other small ones. V5 is the driver for the 4 EL34 output valves and the ECC83 Should be balanced ( if you didn't know there are two halves to the ECC83 - one half drives 2 of the EL34 and the other drives the other 2 EL34s). It is just a start but you would be cheaper to get the valves tested rather than do a complete re-valve. I hope this may help.

 

[CVS]

Hello,
I own the same amp and when i used it at first i had the gain on that channel on 8, but i had to return to about 6 to have a good sound on OD2 and a little bass turned down (4/5 or 11/12 o'clock) tha

 

[CVS]

Hello,
I own the same amp and when i used it at first i had the gain on that channel on 8, but i had to return to about 6 to have a good sound on OD2 and a little bass turned down (4/5 or 11/12 o'clock) that did it for me . it could sound better with single coils so you could use OD1 with humbuckers and OD2 with singelcoils...
i had the same thinking with my dsl20H: sounded ok but with my les paul on the bridge pu and gain at 6 or 7 ...too muddy - first tried other tubes but no solution ...searching for compromises in eq and gain or maybe use external pedals like OD or Eq
Let me know what works best for you ...

 

[Mike Reynolds]

I would also concur that the amp sounds as it should at those settings. Bass setting too high will cause poor sounding distortion. In fact all the tone settings up is hurting the sound.

 

[Pete Farrington]

you need them tested to know for sure

I’m not sure about that, many valve testers are BS, what actually matters is how well any individual valve works in its intended application.
All he need do is to buy a known good ECC83 from a reputable vendor, burnt in and checked, using a high spec tester.
Then swap that into each valve socket in turn, checking whether the amp’s sound improves.
If it does, that’s identified a valve that should be replaced.
If not, replace the ECC83 that was previously in that socket, and repeat the process on the next socket.

In this case, as @hosselausso seems to be using the ‘direct out’ (rather than the speaker), the power amp section V5 - V9 isn’t in the signal path, so there’s little point in messing with them.

https://www.drtube.com/schematics/marshall/jvm410hjs-62-02-iss1.pdf

V5 is the driver for the 4 EL34 output valves and the ECC83 Should be balanced

I think that’s something of a widely held and promulgated misapprehension. The long tail pair LTP circuit is what generates the balanced outputs, all it requires is 2 devices of the same type (V5 ecc83 in this case) that have reasonably good functionality.
The LTP uses negative feedback NFB to achieve that, with most of the gain provided by devices being used by the NFB to balance the outputs.
Hence there’s no benefit from the devices used being ‘matched’, they just need to be reasonably functional examples of their type for the circuit to operate as it’s supposed to.

 

[hosselausso]

Hi,

Thanks everyone for all your answers, you all are awesome!

Let me try to give you my thoughts why I was using Gain 10 and why I was wrong.
Setting the gain at something below 10 was not giving me enough punch for solos, of course for rhythm it makes better sense to turn it down to 6 or 7.
I also watched a video from Joe's rig rundown showing his settings.. gain was at 10 as well, so I just copied it (big mistake from my side).

Also, there were some questions about why I'm using emulated output... I used this amp before in a couple of live events, not many though, but now I'm just playing for fun at home... and I can't really dial the cabinet more than level 1 (and that's too much).. so I can't mic it to record it at home (even though I have SM57 and E609 I have for live events). The emulated output is not that bad though... it's pretty decent, even though it only offers the default IR from Marshall... I connect it to my DAW and tweak the EQ and other stuff.

So, I've been playing around a bit with different settings and I have recoded a video (sorry for the bad quality)


It's recorded directly from the emulated output, no EQ used neither any effects (despite some delay at the end). I have to say that having the gain at 5 and engaging a TS9 sounds great.

 

[AlanHarper]

I do use a good tester... AVO mk4...

 

[Chris-in-LA]

Seems to sound better….

 

[hosselausso]

First of all, that Amp sounds normal but back up that Gain and Volume a tad..
2nd the DI output will ALLWAYS give you fuzzy tone if there is no Amp Sim/IR utilized to record as it plainly taps off the Sound after the PreAmp so no Power Amp and Cabinet involved to shape the sound as you expect it..

The direct output is emulated with a IR from 4x12 marshall cab with Celestion V30.

 

[hosselausso]

The low notes sound really fuzzy whereas the higher notes don't sound too bad.

The gain is set really high for a JVM. Is your string action too low so you don't have the sustain you should so you're compensating by increasing the gain?

Even for the high notes I noticed them too compressed. After moving back gain to 6 or 7 it improved a bit. Thanks!

 

[CVS]

Hi,

Thanks everyone for all your answers, you all are awesome!

Let me try to give you my thoughts why I was using Gain 10 and why I was wrong.
Setting the gain at something below 10 was not giving me enough punch for solos, of course for rhythm it makes better sense to turn it down to 6 or 7.
I also watched a video from Joe's rig rundown showing his settings.. gain was at 10 as well, so I just copied it (big mistake from my side).

Also, there were some questions about why I'm using emulated output... I used this amp before in a couple of live events, not many though, but now I'm just playing for fun at home... and I can't really dial the cabinet more than level 1 (and that's too much).. so I can't mic it to record it at home (even though I have SM57 and E609 I have for live events). The emulated output is not that bad though... it's pretty decent, even though it only offers the default IR from Marshall... I connect it to my DAW and tweak the EQ and other stuff.

So, I've been playing around a bit with different settings and I have recoded a video (sorry for the bad quality)


It's recorded directly from the emulated output, no EQ used neither any effects (despite some delay at the end). I have to say that having the gain at 5 and engaging a TS9 sounds great.

Glad to hear ! rock on !!!

 

[Spanngitter]

The direct output is emulated with a IR from 4x12 marshall cab with Celestion V30.

Nope, for a proper IR it would require a DSP Treatment with the correct Impulse Response. The DI Out on the JVM is a simply R/C Filter cutting down the Frequency to a range between 100Hz and 7kHz supposed to sound like a 4x12 with V30 (which is beside the 20/80 and T75 IMHO one of the worst speaker Celestion ever designed )