Crate Voodoo 60 combo Blue

[bsco]

Things in your home can affect it as you see, but also, a guy a half mile down the road could start up his table saw or an air compressor and bounce your voltage. And I was serious about highly watched TV shows, when significant percentages of the population all watch some event, the cadence of the show often affects the mains.

Ok. I seem to have this figured out......After I cleaned this beast up and soldered up all the bad corroded connections, and sorted out my scope probe issue, The location of this low level noise was related to the first two stages......but........ the noise would disappear when V3 or V4 were pulled....If I pulled V1 or and V2, that noise was still there...I scoped the plate of V4...pin6....I could see noise .....scoped V4 pin 7 and the noise was on the grid as well but much lower......but there was no noise on V3......so I went to V2....scoped the plates pins 1 and 6...the noise was there....so I replaced the tube.....the noise was still there.....so......I scoped V1....the noise was there as well but very faint....so I replaced that one as well.....I'd be dammed if the noise was still there......I removed the tubes and gave the sockets a good cleaning.......still there......I scoped the grids and cathodes...no noise......put the old tubes back in...still noise.....cleaned the tube sockets pins again and tightened them up slightly......the noise was still there....replaced V2 and V1 again.....now the noise is gone..I ran it for a bit this morning and so far so good....the amp is very quiet......I should also mention that I did have a couple of plate load resistors that were out of spec which is why I decided to replace all of them while I was in there.....as it is a PINA to keep removing and installing the board....and I don't like tack soldering components to component leads that stick up through the board...it might be faster but looks horrible....and somebody was already in here and did that kind of stuff so I cleaned all that up.....so it is working.......now I just have to put it back together and then run it for an hour or so.....the AC line voltage is the same 123VAC.....so no change in that from last night.....anyway, thanks for the proper schematics and anybody who offered me advice along the way....it is much appreciated.......
Cheers