Hi folks,

I've had an SE84B (#180) for about a decade. The person I originally got it from gave it to me because "it had a buzz sometimes." I figured it was filter caps, but the buzz was very intermittent, and after I listened to it for a bit, it went away. I have been happily listening to it since. A few days ago, the noise came back. It only happens when the amp has been on for a few hours, is in both channels, and it goes away the second you flip the power off. Again, I figure it's probably filter caps. I am going to replace those soon.

While I was just in the amp, though, I noticed that the bias switch has been disconnected and the resistors were just left hanging there. Was this the work of Decware? Seems like maybe not a good idea to have those resistors just hanging there not terminated, no? Pics attached. Looks like I cannot post images yet. So: the resistors which are attached to two of the lugs of the bias switch have been snipped at the switch and are bent back, floating in space (very close to the output trannies)

thanks for any insight! (including if you think I am off on the filter caps)

I should have added: I have recently refreshed all the tubes and I have switched out tubes when it's making the buzz with old ones and its unchanged. So it's not tube related.

It does have a bias resistor. The way it works, the bias switch either does or does not add in another resistor in parallel to the existing one. The one that's clipped is the additional one, so basically the mod means it's always biased "cool."

And yeah, the whole nature of this sound doesn't remind me of filter caps. It sounds like kind when someone puts their hand on a microphone. More like dark static. But given my tests its coming from the power supply somewhere. And if its not the caps, I think that means its the trannie, which would be sad as I am pretty sure replacing that will be cost prohibitive.