Just got my amps back from amp tech/builder after wish list was completed..joy! tonal bliss!!in order Thumper-JMP50--1987 circuit now 2204 PPIMV spec on Hoffman board.el34. modded to thump & it is punchy ! 45er-JTM45-45 circuit close to original 6l6 bigger tranny.values changed.classic 45 tone but a lil more mid .very tight bottom or classic 45 squish.pedal handler supreme. UJ the 45-Union Jack Amp(now Rola (verified this with original builder) JTM45 circuit w el34 SS & tube rec..very aggressiveness.this thing can rip things apart without a fizz..so heavily modded to personal taste. Lots of value changes & trial &error.This is my Black Flag All wiring gone over,solder joints & many hours of tweaks to make the classics personal yet retain what they do originally From the jtm45 off the bassman circuit to the el34 application 2/SS& tube rec to the plexi..the lineage when you play em right in a row..you hear it but you feel it in your hands, the manipulation of a pretty direct simple circuit & vol & tone riding on guitar..man ..time can get lost playing !!