Marshall looses gain after 2 mimutes

[Rod]

Strange problem in my Marshall jvm here, after some minutes being on the starts slowing loosing gain, what hell can the problem be?

[Helmholtz]

Could be many things.

We don't even know which exact model
Please post schematic.

[Rod]

Hello!

Here you have it.

http://musiciansroadhouse.com/viewtopic.php?t=11597

I'm going to check the tubes, to see if have somekind of problem with them and then let you know.

[Helmholtz]

What model?

[vintagekiki]

What model?

#3

[Jon Snell]

Have a look around here;

[Helmholtz]

#3

So what is model #3?

Not going to waste my time with guessing what's the appropriate schematic out of a list.

[Rod]

I changed tubes and they seem fine, i tapped all the components and i see that the filter capacitor C47 and C49, are very sensitive, by tapping them i see the sound changes can this be the problem?

If its not the filter capacitor maybe something around that area or the tube in that spot of the preamp.

[vintagekiki]

http://musiciansroadhouse.com/viewforum.php?f=54
Marshall JVM

[g1]

Hello!

Here you have it.

http://musiciansroadhouse.com/viewtopic.php?t=11597

I'm going to check the tubes, to see if have somekind of problem with them and then let you know.

There are 2 sets of different schematics there, for the 410 and for the 210. Which one do you have?

[Rod]

Hello i have the jvm410h

[vintagekiki]

Strange problem in my Marshall jvm here, after some minutes being on the starts slowing loosing gain, what hell can the problem be?

Question
Whether loosing "gain as gain" or "gain as power".
If loosing "gain as gain" whether loses gain on all channels or on some.

Test
When starts slowing loosing gain, connect the guitar to JS4 (PA IN RET) and describe what you hear.
Connecting the guitar to the JS4 the guitar connects directly to the power amp.

[vintagekiki]

There are 2 sets of different schematics there, for the 410 and for the 210. Which one do you have?

All schematics for the JVM is on the JVM410
Set JVM210 mainly describes difference footsw and front pcb.

[vintagekiki]

Hello i have the jvm410h

http://musiciansroadhouse.com/viewtopic.php?t=21769
Marshall JVM 410HJS

[Rod]

I have the standard JVM 410H not the satriani model JVM410HJS.