Tube Amp Archive

Finished project

Thanks to everyone the reverb buzz problem is solved, had the reverb tank in backwards now the amp is complete, quite as can be, super tone and lush reverb. Trem is also to die for, so a big thanks to all of the amp guru's that helped me solve several problems.

Does the reverb tank have rca jacks facing the speaker or the back of the amp?

Got reverb working but has a buzz that gets louder that higher the reverb knob goes, if I unplug the send cable buzz still there, if I unplug the return cable buzz is gone. Any thoughts?

Found the green wire from the reverb transformer was grounded under the screw that holds the tranny in place, it bit right through the plastic jacket. Fixed that problem and same thing, just buzz but if I tap on the pan I can hear the tank crash faintly in the speaker. Did I fry the reverb tranny?

O.K going bad solder joint using audio probe fixed that and volume is blasting loud, and the term is heavenly. Reverb on the other hand is not present, just get buzz when reverb knob is turned up. Can I trouble shoot that with the audio probe, and how Please almost there. Thanx

Yes bias set with bias calculator and Hoffman bias probe

Can someone show me the signal path to test with my new audio probe please, and including the reverb

Brand new Weber speaker pretty much made for Princeton Reverb, as far as tubes I don't have any others to try but these are match pair made by Tung-Sol. I know that doesn't matter but going to try the audio probe tonight and see if I can find anything wrong.

Good call! i'll try it tonight

I have checked the blue caps with my Fluke cap meter and they test right on at .1 and .047, don't know how to do AC test in preamp stages.

Here are some gut shots

All of the voltages on the Fender schematic are pretty much the same as mine except just slightly higher due to a Mercury PT that puts out 355volts ac on the primaries.

What about the OT, its a brand new Mercury Magnetic but could it be bad, how do you test an OT?

I checked every value of resistor and everyone of them is correct. The kit came from Mojotone, the only parts I substituted was vintage blue molded Fender caps