This only occurs once I've had the Crack on for an extended period of time, like an hour. I believe the problem lies within the larger tube, in this case it's my Tung Sol 6520 with the domino flat plates. When I start to notice the ringing, which is quite faint, it's only in my right channel and it stops for a while if tap the tube or chassis near the tube. I decided to swap out the tube to see if it was the tube or if the problem is somewhere else. I plugged in my old RCA 6AS7G and it all seemed fine until I got about an hour and then I noticed the ringing again, but with this tube in I heard it in both channels and the sound was much more pronounced - something I believe to be because of the tube. The Tung Sol just has lower noise and is a nicer tube. So I'm not sure if it's the tubes that are giving off this ringing sound or if the problem is somewhere else in the amp. Where should I start with this problem? Re-flow some joints? I feel like I've done this over a dozen times now, but who knows.
Anyone else ever face this problem?
also, just to be thorough, my other tube in the small socket is an RCA 12BH7A. And as I'm typing this I have yet to swap that tube out to see if that resolves the problem. I'll try that later and update.
