I need some help troubleshooting a low frequency oscillation in a tubeamp SOLVED

[Planobilly]

Back...ok Bob I understand now...I will go dig up a Ceramic cap

[Planobilly]

That did make some slight change. The oscillations are more intermittent and  I have to turn up the gain to hear them well.

Any value in placing ceramics on V4a and b??? 

[uncle_bob]

Hi

If the electrolytics you got have high frequency issues adding another ceramic to V4 might be a good idea. I would go slow and check after each change.

Bob

[Planobilly]

I found the problem.

A few days ago AT&T installed a new router in my shop. I was not here at the time and it got installed under my workbench.

Interference from the router caused the amp to display a sound that sounded just like motorboating.

What a pain in the ass problem to have to deal with!!

Cheers,

Billy