High pitched whistle?

[boobtube21]

No, not on the HRDx.

I went and tried out one of those Roland JC120's (used, and pretty old)at the local music shop yesterday, and was actually very impressed with the clean tone.

Only problem with it was this high-pitched whistle (not really loud, just high in pitch) that only went away when I turned my guitar volume down. I've seen older plexis that whistled when you turned the treble up too high, but this was something else. I tried turning every knob on the amp, plugging into both channels, plugging into a different outlet (probably on the same circuit ), nothing got rid of it though.

I know this is a solid state amp that not many of you have probably worked on, but nonetheless does this problem ring a bell at all? I'm hoping it's something simple, like a bad cap or transistor. I'd like to go back, offer them maybe $100-200 for it and fix it myself.

[JAM]

bt21,

I cant help with the amp, but you might try posting this question over at Ampage, there's a lot of amp techs over there, someone may be able to help.

[boobtube21]

Thank you JAM, I will try over there.

Anybody here who thinks they might know what the problem is can still feel free to help though.