Help with Ampeg J-12R Jet ll

[Doc Stitches]

1996 Reissue Ampeg amp always sounds fuzzy/distorted.

I will disassemble and clean the pots for sure.

What is the value of 3 components ?....especially C31

C31

R11

R12

I can't read the schematic and can't even find C31...

Thanks
Doc Stitches

[Enzo]

What schematic are you looking at, can you post it or link to it?

What led you to ask about those particular components?

I see R-12R and J-12T. I don't offhand see J-12R.

However, on the J-12T, R11, R12 are each a 1meg grid return resistor for the phase inverter. So it would make sense to group them.

Also on the J-12T, C31 is the ground coupling cap. 0.1uf 50v. Schematically it is right by the input jack, it links the circuit common ground to the chassis. Physically on the layout it is in the rear corner straight back from the input jacks, right next to the ground screw to the chassis. COnsidering that it couples the chassis ground to the circuit ground, it probably measured "shorted" in circuit.

[Doc Stitches]

Enzo
thanks for the response.

I could not find the right schematic for the Jet ll ....so the closest one I could find was R-12R, but it has features mine doesn't have like master volume and standby switch.

I asked about C31 because this board has 2 of them and the readings are not the same.........one barely even registers.

embarasing update.......later that same day.........I just got my Hickok 600A from Ebay and tested the tubes.....uuhhhhhhhhh.....you guessed it......2 bad 12AX7s......and........duh....bad speaker.

Ampeg J-12R Jet ll sounds like new.

I think I'll have another piece of very...HUMBLE PIE !!!

Thanks again
Doc Stitches