Sluckey! ( Shacks final PR troubleshoot .....I hope)

[Shack]

I found a major problem, but it leads to a couple questions...


First, the 2 220k resistors on the phase inverter...I had both grids hooked up to the same resistor ( easy mistake for me with this layout.)




my question, I have the wires going to opposite tubes from the layout.....might that account for the real loud hum when tubes warm up?



The cathode voltage on reverb tube (v2) is still 40 vdc

[sluckey]

You have your discussion about this PR spread over a half dozen topics. Please keep it all together in a single thread so people don't have to go searching for relevant info in another thread.

my question, I have the wires going to opposite tubes from the layout.....might that account for the real loud hum when tubes warm up?

If your 'real loud hum' is more like a howl or squeal, then yes. That would accomplish the same thing as swapping the OT plate leads to correct a NFB phase problem. Swap'em and see what happens.

What are the voltages on every pin of V2?

[Shack]

Sorry about that    I thought about deleting the other 2 threads , but couldnt figure out how.
 
Anyway, I reversed them and the amp now works ..

On V2...both plates are 352 v , both cathodes are 40 v , and 0 on both grids.

I do appreciate the help and patience shown to me.

[sluckey]

What kind of tube is plugged into V2 socket?

[Shack]

GT 12at7....I have 3 different ones, and ive swapped them

[ac427v]

I "have a friend" who used a 22k cathode resistor instead of 2.2k. Is there any chance of that here?
The turret in the center of your photo does not have its jumper wire soldered in place. You don't want to forget to do that before putting the amp in the cabinet. Vibration related glitches can be hard to troubleshoot.
--Craig

[Shack]

lol...no, I double checked...its 2.2k

[DummyLoad]

no solder? see pic.


--pete

[Shack]

I will work on that stuff,and report on progress in this thread, sorry for making multiple threads....didnt mean that.