PJD12
The owner of this amp had bought it second-hand, it is a british built Fender Deluxe copy with a mod to remove one of the quirks of the 5E3 circuit - that the two channels interact with each other. What he found was an amp that didn’t break up, sounded odd and despite some digging was struggling to find out why.
Inside, he was told, was orignial out of the workshop. A ragtag collection of components and you’ll see the dual tone stack pot which is the mod by which the two channels were isolated from each other. I didn’t think it sounded right either, I struggled to believe this hadn’t been played with at some point.
The owner wanted it back to stock the stock 5E3 circuit and that is where we started new filter caps at the right values, all the other caps replaced with new components of much higher spec and a bit of loose wiring re-done.
Eagle-eyed viewers will see a new switch at the bottom, this was my implementation of the Rob Robinette NFB cathode switch where you switch between a bypassed or un-bypassed V2 cathode or add in negative feedback. I’m glad to say that in the end the customer was really happy with it.