Jose Master Volume

[V2a]

Worth tinkering with or does it sound like buzz saw gain much like lowering the cathode resistor from 10k to something lower can sound in an 800? I can't go any lower than 8.2k for my ears... even at that it is a little too buzzy)

If you want to increase the gain in an 800s, then you need to play around with more values than just the cathode of V1B: you can go down even to 1k here, but then you need to play with the pot's (gain) value (less, solder a resistor in parallel to the pot's input and ground) and the voltage dividers - as well as the values of the coupling caps (less nFs) - and use grid stoppers in front of the CF . . . just look at some schems of higher gain amps with three stages - I'd start with the crunch of an X88R or similar.

One can get enormous amounts out of three gainstages without buzz (Diezel VH4 - ch3) . . . the post-CF MV won't be a big help btw . . .

Is the x88R crunch channel the one running across the middle of the preamp schematic (2nd of three channels)?

 

[duesentrieb]

I think so.
2nd stage has a 2k2 cathode ("naked", no cap) and a 680k/330k divider followed by a 220k grid to the CF. Sounds nicely "meaty" IMO.

 

[V2a]

I don't want to hijack the thread, but I think this question is germane to previous points: doesn't the x88R crunch channel have one more gain stage than the JCM800 (4 vs. 3)?

 

[duesentrieb]

No. Both have 3 gainstages and a CF.