Tweaker 40-112 combo ringing noise

[Jay Tea]

I've got a Tweaker 40-112 combo, and it's making a high-pitched ringing noise when I play certain notes, usually the 12/13th fret on the B string. I've read about tubes ringing, but I tried taking the back off and wasn't able to narrow down where the noise was coming from. Is there a better way to figure out where that's coming from? Is it likely to be something I can fix easily?

 

[Buckeyedog]

It is likely a pre amp tube. Do you have some spares? (You should always have some good one's on hand). Try tapping each pre amp tube very lightly with a pencil eraser and see if any ringing or noise comes out. They go bad/microphonic........just the nature of the beast. If that doesn't work, take a good tube and swap out each pre amp tube one at a time and see if that changes anything.

 

[rjferretti]

I experienced the same with mine after three weeks. Sweetwater replaced it. Now month one of the new one and every time I play a C# note single or chord it sounds like aliens are coming out of it. Totally unusable amp IMO. Sent a recording to Egnater waiting for response. My sales rep at Sweetwater talked me out of buying a Fender Hot Rod Delexue and getting the Tweaker. I am sorry to say I am regretting this decision. I never had problems like this in the past. I sold my 1990 Mesa Boogie Mark 4 about three years ago for a $,1000 still had original tubes in it. Now that's money well spent.

Update:

Sweetwater, offered to replace(again) or give me store credit. I took the credit. Sending the amp back tomorrow(again).

 

[daviedog]

Wise choice!..