wolf1419

I need help diagnosing a VS265 Valvestate stereo chorus comb0, 2x12, 65wx2. ......chorus, reverb, 3 channels(all working fine) - Left side sounds fine, right side is crackly, noisy, distortion, lower level, etc.......even through the headphone jack as a test that it's not the speaker.
Can anyone work with me to diagnose this amp issue without going to a shop, as this is my alternate electronics project and learning experience.

wolf1419

Any ideas guys....? I don't know where to start.

Pete240885

Ok so if i understand this right, your Right channel is noisy, crackly and distorting even at low volume levels.

What kind of noise are we talking about? hiss? hum?

wolf1419

A better description would be distortion, weak/lower volume level, hum not noticeable on the right output(speaker, or headphones), even at lower levels, all channels, so it is somewhere just before the output stage where it splits to stereo/chorus.....

Pete240885

Ok I'm guessing this problem occours with the Right DI out aswell?

Pete240885

It had better be i'll be confused if it doesn't lol

Pete240885

Hmm distortion and lack of gain

ok could be a bad solder joint, IC or transistor, the question is where I think we could rule out anything before IC11b (excluding the components that work with it), ok as a quick diagnostic for that i'd like you to swap the connections from the daughter board to the POWER PCB circuit diagram arround, so that the left and right channel feed are swapped, according to the schematic this is pins 1 and 2 on CN2, if we're lucky the problems will now be on the left channel, meaning we have very few components to worry about:

R82, R83, R84, C38 and IC11b

as opposed to the whole of the right power amplifier.

PS schematics can be found on the same website as the valvestate 8100

wolf1419

Pete,
Thanks for helping again. Now I have to disclose my disability called CFS(Chronic Fatigue Syndrome) that is going to put me out of commission for several days - I will get back to you when I'm able to do this investigative work. This is a debilitating condition that takes me down when it wants and without much warning.... Talk to you soon....

Pete240885

hey don't worry about it, my friend suffers from the same thing so i'm used to what it can mean, thanx for letting me know that you havn't just dissapeared