Gibson GA-77RVT 1963/64 specific schematic

[CB Amp]

Hello,

I've got a Gibson GA-77RVT Crestline (#710095), with a very specific circuitry, distinct from the schematic found on the web or in the Tube Amp Book.
It has an OA2 tube, the bass pots are 10Meg (!). I re-draw the schematic, but it seems that some people did some mods on it (really crispy sound with a lot of treble, reverb on both channels).

The amp has the following tubes : 6EU7, 6EU7, 12AU7, 6EU7, 6EU7, 6CG7, 6L6, 6L6, OA2.
Does anybody have the original schematic of this model ? It would help me a lot.
Thank you.

Here is a pic of the amp (found on the web, but mine looks exactly the same) :

[img:640:480]http://online.physics.uiuc.edu/courses/ ... nguard.jpg[/img]

[martin manning]

You could post this request over at the Music Electronics Forum.

Check this thread there:

http://music-electronics-forum.com/show ... ine&page=2

"Capnjuan" is still on-line, and maybe he has what you're looking for.

MPM

[gahult]

See if this is it.

Gary

[CB Amp]

Thanks for the replies and the schem Gary.
Unfortunately, it's the "normal" one. My amp has an extra OA2 tube, and the circuitry is completly different... Gibson engineers were funny guys !

[gahult]

OK, try this one.
Gary

[CB Amp]

Thanks again Gary. But it's not the good one too...
I've got a lot of schems, the current ones. And I tried to find on every website (schematicheaven, freeinfosociety, etc...), and to look at other amps that could use the same circuitry, but I did not succeed...

The RET model has the same vibrato circuit, and about the same power supply and power amp. But everything else is different, preamp, reverb of course, phase inverter. And that's where my problems are...