Tube Amp Archive

Hi Pete Electric Guitar Amplifier Handbook by Jack Darr has a quite a few examples on how to use a scope to help troubleshooting. It also has a lengthy discussion on amp repair and troubleshooting in general. A must have book in my opinion. Edit: It is possible to get a new reprint in paper, but you...

I thought I owed you guys an update. You were right on Glen. After trying all sorts of more or less dubious stuff, I redid the tonestack form the ground :lol: and up. That did the trick! Holy mother... I wanted gain, harmonics, sweet feedback and tube distortion... I got it all and a bit more than I...

Today I changed the offending volume pot, but the problem with squealing when turned all the down is still there??? The other problem with no break up - also still remains after switching tubes around and changing completely. It's very strange, I have very nice cleans and headroom all the way to 11 ...

hmm, please pardon my ignorance but I'm not sure as to which pins on V1 you're referring to as wrong. I can't seem to find the information in the link you provided?

I have uploaded some pictures (yes, I know that the tube sockets are ¼ turned compared to normal layout ).

fishy: I'll try to add some photos tonight. jjman: Yes, the first thing I tried was switching the OT primaries and it squaled in every configuration. That also doesn't explain the lack of breakup... I have a feeling of what I'm hearing is only the outputtubes.. could that be it? Also, is the voltage...

Hi, new express build done this weekend and I got amplification but alas not the expected kind. I’m hooking it to a 2x12 Marshall cab and yes it’s loud but not insanely loud at full throttle. I have no breakup at all, it just gets a little grittier at full volume. Another strange behavior is that wh...

Me too! THX

Hi Ron (and everyone else) First time poster here.. Hello, and thanks for all that wonderful information in this forum :D I think there is a tiny error in the Express BOM. On the sheet with 'Capacitors' you got the same Supplier PN for the 500pf and the 47pf caps. The number for the 500Pf cap should...