Tube Amp Archive

Here's info I got from Jorg @ Bogner today. Any thoughts on this? Hi Larry, What is the serial number of the amp? We have never used C-winged Svetlanas in that amp, JJ's. It shouldn't be a problem to bias an amp for a Tech, bias always depends on brand and individual grade of the tubes. With input A...

Since it only takes place on one channel you can rule out the PI and output stage. I would start off by replacing all of the plate load resistors and cathode bypass caps in that preamp section as this is a cheap and fast way to shot gun that, and any plate load resistors that may have close to 350 ...

All my higher gain amps do that at my house. It did not do it where I gig. I found out it was my neighbors electric fence that my home supply was picking up through ground. We turned off his fence momentarily and it disappeared. A power conditioner helped in the end. Thanks for the reply! I'm certa...

I purchased a used but mint 20th 101B not too long ago and the clean (green) channel has developed a "popping" sound. It doesn't start right away it usually takes about 10-15 min to start and it starts out kind of sporatic but then gradually gets faster to where it pops like 2-3 times a second. It's...