.50Cal+ noise question...

[scottcrud]

It's a 1989, been played quite a bit at loud volumes. It now has a high pitched squeal if I turn the treble above 6 or so and the gain over 7. It has all new preamp tubes, I've even switched em out for known good pre's from my nos stash...same result. Since it's almost 20 years old could it be time for a cap job?

 

[rgx612a]

I don't think bad caps usually cause squeeling, but i could be wrong? loud Hum is a more common problem with bad caps.

Take it to a tech.