[FloridaBoy]

Originally Posted by pechelman

also have some quiet 120Hz buzz that i've been trying to isolate with the new 3.1 ultra preamp. Can really only detect it in very quiet sections of music or between tracks.

It appears to not be a ground loop, tried a cheater plug and a humx adapter. Have tried 2 different rectifier tubes, but both seem to still produce appx the same amount as the "5Y3GT" Sovtek rectifier he supplied with it. I put that in quotes because as I understand it isnt a real 5Y3 since it is indirectly heated.

I'm 100% certain the buzz is coming from the preamp as when I removed it and kept all the other components in the signal path, all is dead quiet. Any other thoughts where I should look? Possibly the 6BX7 buffer? There's about ~12" between components on my shelves. Will try the tip above at physically moving the preamp a little.

Should I look for some different rectifier types? Since the Sovtek appears to have less voltage drop than a regular 5Y3 I'm guessing I'd be safe to look at other tubes without rebiasing or worrying about filter caps? Like 5AR4/GZ34, 5V4, 5W4, or 5Z4? Or am I just barking up the wrong tree here trying to remove this buzz?

Ask Dennis about rectifiers other than 5Y3's before going there.