Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: OrganicEffects on May 16, 2018, 03:42:57 pm

Title: AA763 based mod idea's
Post by: OrganicEffects on May 16, 2018, 03:42:57 pm

Hello  :icon_biggrin:

http://www.thevintagesound.com/ffg/schem/super_reverb_aa763_schem.gif

http://www.thevintagesound.com/ffg/schem/bassman_6g6-b_schem.gif

I've been waffling between building a BFSR and a 6G6-B Bassman for.. probably too long. Never played the blonde bassman, but that bass channel set up is very intriguing! I have played the Super Reverb and really like it, but the main deterrent was the complexity with the trem and reverb, which I didn't use much anyway.

So I figured I'd go a custom route and toss a couple ideas up here for you guys to evaluate. I started with the normal channel of the AA763 Super Reverb, which would have been super simple, going from 9 tubes to 5 and removing a tone of the wiring. At this point, my tinkering side has taken over and I started thinking about what else I could do with those unused tube holes  :icon_biggrin:

Exhibit 1 and 2.

https://imgur.com/a/eE6GVMw

#1 is the standard AA763 with a triode before to add some gain. Then I tacked on the weird treble/triode stage from the 6G6-B and tagged it on to the end. Would it sound any good? No idea. Would it work?  :dontknow: :dontknow: :dontknow:

EDIT: is it that much different than some of the TrainWreck express stuff...

#2 I thought it would be cool to have a lead channel blended in, rather than get to distortion levels through increased volume. I had started with just switching the gain stage in from #1, but I like turning knobs, not switching switches! I couldn't think of a way to have this blend in without buffer the input with another triode, which is what the bottom tube is doing. Is there a better way to do this? Basically a blend control rather than a volume? I'm afraid it either won't work, or V3B is going to change the sound too much when V3A is turned down. Perhaps this would be better accomplished with a dual 1MA pot, wired like the volume controls of a tweed bassman, but one of them backwards.

Is there anything else I should be adding into this amp (not trem or reverb) that would make the tone a bit more versatile, while still be able to set the controls back to a standard BFSR sound?