Home  Resources  References  Tubes  Forums  Links  Support 
how to increase gain with a single 12ax7
7/9/2007 9:43:22 AMblackbird
I was doing a ac job down in the san fernando valley,
(CA) when I saw a old magnavox console record player dumped by the curb on a move out. Unfortunatley the record player and tuner section were gone. But hello! a main amp! A 6v6 PUSH PULL unit was still there!! So I yanked er out, capped her and put it into my guitar amp project. (oh I got rid of the old ac/dc chassis,I was using, that had everone scared by the way...lol)
This thing sounds nice! no hum whatsover.
I also put 5881 tubes in it...my farorite. like the old bassmans. anyway it has one 12ax7. what can you do to add an ADJUSTABLE gain to it? It sound great as is for bass, but would like a lil zing when I play guitar. should I modify it, or just use a stomp box?
7/9/2007 9:49:09 AMNorm Leal
Hi

You need to add a preamp. A single 12AX7 driving 6V6's or 5881's just won't have quite enough. One section is probably being used as a phase inverter, no gain.

Norm

:I was doing a ac job down in the san fernando valley,
:(CA) when I saw a old magnavox console record player dumped by the curb on a move out. Unfortunatley the record player and tuner section were gone. But hello! a main amp! A 6v6 PUSH PULL unit was still there!! So I yanked er out, capped her and put it into my guitar amp project. (oh I got rid of the old ac/dc chassis,I was using, that had everone scared by the way...lol)
: This thing sounds nice! no hum whatsover.
:I also put 5881 tubes in it...my farorite. like the old bassmans. anyway it has one 12ax7. what can you do to add an ADJUSTABLE gain to it? It sound great as is for bass, but would like a lil zing when I play guitar. should I modify it, or just use a stomp box?

7/10/2007 9:33:30 AMbb
bummer thats what I was afraid of. Most of the high gain amps I see have two or three 12ax7s.

:Hi
:
: You need to add a preamp. A single 12AX7 driving 6V6's or 5881's just won't have quite enough. One section is probably being used as a phase inverter, no gain.
:
:Norm
:
::I was doing a ac job down in the san fernando valley,
::(CA) when I saw a old magnavox console record player dumped by the curb on a move out. Unfortunatley the record player and tuner section were gone. But hello! a main amp! A 6v6 PUSH PULL unit was still there!! So I yanked er out, capped her and put it into my guitar amp project. (oh I got rid of the old ac/dc chassis,I was using, that had everone scared by the way...lol)
:: This thing sounds nice! no hum whatsover.
::I also put 5881 tubes in it...my farorite. like the old bassmans. anyway it has one 12ax7. what can you do to add an ADJUSTABLE gain to it? It sound great as is for bass, but would like a lil zing when I play guitar. should I modify it, or just use a stomp box?



© 1989-2025, Nostalgia Air