1974 50w lead HELP NEEDED!

[PeterJ_22]

Ok so changed the mains and screens filter caps (left the preamp) and still same deal. Nothing changed... this is getting stranger and stranger

[PeterJ_22]

Actually tempted to just build a PTP board to put in there. I hate pcb at the best of times.

Ok so ordered all parts / board / mustard caps. Just going to put in a new ptp board and sub in old parts one by one till I work it out.

[SDM]

Looks like you are using a "modern" style presence pot hook up there. Do not see the (typically 4.7K) tail resistor on the pot though that you need for that setup.

Don't know if that is wiring is a mixup from swapping out the presence/NFB values, but either need to use "old school" wiring (with a 5K presence pot) OR (for modern style), that 4.7K added on the pot for starters.

[PeterJ_22]

Wow so it was as simple as the presence pot wiring haha.
Wish I figured that out before spending $200 on parts to rebuild a board (mustards etc)
and 6 hours rebuilding the amp in the first place!
I just changed it to the .1uf cap going from middle to left lug and left lug to ground and its fine!

Thanks !!!!!!!!!!!!!!!