Tube Amp Archive

So you had this problem...swapped out the socket and the problem remained...then removed/cleaned the socket and that did it? That's so weird...I can't tell you how many times I've thought "it's gotta be the socket...everything else has been checked" and I'll swap out the socket...and it's never the...

Problem Solve !!!!

I removed the tube socket, clean it rewire it and its working fine now...

Thank you so much Guys!!!

PI voltages look screwey.. you should have around 230-260 on the plates common Cathode looks close @ around 100v.. Check Presence circuit phase inverter tail, and bias supply.. Tony VVT Changed the PI, Tail and presence resistors & coupling caps no luck... guys, more suggestions please .. :cry: :cr...

moj067 wrote:Check that V3 socket for continuity to all pins, swap it out just to clear any doubt.
Clear boards do make looking at things under boards easier

Socket is good & tried to swap it also, no luck..

mlp-mx6 wrote:Are you sure that the V3 plate resistors are the correct values?

Yup, I double check the value it is correct.

mlp-mx6 wrote:If you remove V3 what does the voltage show for both plates there? With V3 in what do the cathode voltages show?

with out the tube

V3a = 436
V3b = 421

I tried other tubes on it .. same problem.

V3 with tubes
pin-1 = 373
2 = 41
3 = 93
6 = 47
7 = 97
8 = 93

The voltages on your PI are screwed up. (I'm supposing that was obvious...) The clear board is very cool. Odd to look at, but very cool. Where did you get it? What is it? Thanks mlp-mx! Its a 4mm plexi glass bought it from glass and aluminum shop. Riveted a diy turret with a washer at the bottom wi...

Hello guys! I'm having a problem on my #124 build. There's no sound coming out on clean channel even in full volume. When I switch on the overdrive Strange sound is coming out on full volume. Its not a clear overdrive sound. V1a = 188 V1b = 193 V2a = 197 V2b = 190 V3a = 97 V3b = 373 485 on the power...

Thanks I-racer!!!