Tube Amp Archive

Wouldn't shipping damage be filed as a claim with the carrier used? Sucks you got screwed over but the amp should have been insured for transit...it was right?!? Nothing on eBay is a final sale. Best you can do is post polite negative feedback to warm others. I'm guessing he found another amp for l...

You are looking for an estimate? CTS fender branded 1973 potentiometers 1neg,250k,500k $35 each NOS fender 70's silver face knobs $25 each Labor billed at $60hr Installation and circuit test 1.5hrs Tube testing, bias and break in 1hr 30-day warranty against defective work Hi selloutrr, thank, the t...

Don't know how to enter the photo bucket URL

Hi guys, I don't post much as I'm not as involved in tube amp repair and mods as I would like to, but I need your help if at all possible. I know this one is a little strange and not the typical topic. But I have a situation and perhaps one of you guys out there has a repair shop and can help me out...

short circuit somewhere in the amp So if you use the bulb current limiter and plug your guitar in to the jack can you get a sound out of the speakers? Have you tried a different power transformer? That is to say use a wire with alligator clips to go from the rectifier diodes of one amp to the filte...

Hold on, pin 6 on the PI tube should be pretty close to pin 1 (within a few volts). That triode (pins 6, 7, and 8) is not conducting. You're seeing the supply voltage at the socket (I assume that's where you measured) so check the socket contact with the plate and cathode pins. And, the tube is goo...

Hold on, pin 6 on the PI tube should be pretty close to pin 1 (within a few volts). That triode (pins 6, 7, and 8) is not conducting. You're seeing the supply voltage at the socket (I assume that's where you measured) so check the socket contact with the plate and cathode pins. And, the tube is goo...

Measure and post voltages around the PI and power amp: Pins 1, 3, 6, and 8 on the PI tube, and at the other end of its 470R cathode resistor. On the power tubes, measure pins 3, 4, 5, and 8. If all these look to be in line and stable at idle, then you might try replacing the three 0.1uF caps in the...

Yes, indeed check the coupling caps between stages for DC voltage leaking through. Ideally there shouldn't be any but sometimes a few millivolts. But nothing large. I take it you don't have a scope? Forgive me if you have tried this but do you have another amp that you could input the preamp from t...

Yes, indeed check the coupling caps between stages for DC voltage leaking through. Ideally there shouldn't be any but sometimes a few millivolts. But nothing large. I take it you don't have a scope? Forgive me if you have tried this but do you have another amp that you could input the preamp from t...

Check the coupling capacitors for leakage... that's one of the few things left... you've tried tubes, different OT, changed the plate resistors... The problem is on both channels though. Should I try the three .1 ufd in the PI? I have changed all plate resistors, tubes etc. while I was in there cha...

Hey, yes I changed the OT. I haven't messed with the choke, but I don't think there is anything wrong with it.

sometimes parasitic oscillations can sound like distortion - check lead dress, especially if its a silver face Fender and you were moving stuff around or removing ceramic caps etc sorry if I came off like a dick there. Could the parasitic oscillation sound like halfway decent overdrive? I mean it r...

Hi guys, I'm back. I excuse myself for reviving this post and not posting actively, but I travel every week due to my day job and only today I got back to this POS amp! Still have not found the problem. Things I got to doing after my last post. Changed the bad octal tube socket Relocated the power ...