Jose Plexi mods

[Spencerleehorton]

As far as I’ve read cathode bypass capacitor adds gain as one of its functions, so I can tweak these if needed.

 

[john12ax7]

For 3 stages you can start with the jcm800 for a known good sounding circuit and adjust from there.

 

[Spencerleehorton]

For 3 stages you can start with the jcm800 for a known good sounding circuit and adjust from there.

im already at that point as v1a is going into v1b into v2a, what im proposing is putting in another gain stage before them.
i will be able to switch with relays from plexi to jcm800 and add another gain stage to the jcm800 via a DPDT switch.

 

[john12ax7]

In that case slo100 is a good reference.

 

[dai h.]

here are some posts from Chris Barrow ("cbarrow") on Music Electronics Forum that look like very worthwhile reading:

https://music-electronics-forum.com...-amps/theory-design/6603-biasing-preamp-tubes

http://music-electronics-forum.com/showthread.php?t=7533

http://music-electronics-forum.com/showthread.php?t=12642

plus an "Amp Smoothing Options" thread on Hoffman Amps BBS:

https://el34world.com/Forum/index.php?topic=8579.0

Maybe check out the Headfirst Amps guy's google drive for ideas (schematics and mods--check out JEL (Jake E. Lee)--it's a somewhat tweaked 2204 circuit which seems to show some low frequency tweaking (220k R added across the 1MA pot (helping to reduce "mud"(LF intermodulation)?)) :

https://drive.google.com/drive/folders/1mgmE02iNQrU2n5xnbvnnDbonBQ0J_tNG

Might also want to look at construction details for amps using the same basic layout with (what I gather are) Jose-type mods (Friedman, Dan Gower) :