Bass Amp Head from power amp:

[Arn C.]

I have an old power amp from Audimation corp, S. Plainfield , NJ

120v  50/60 hz 3amp max
4a 125v fuse
(What do you think the output watts is?)
It has 4 output power transistors T03 package  No numbers on them, no numbers on the huge power transformer.  It has a few tropical fish caps, so it is fairly old.

I measured the dc volts of the two large filter caps   +37 vdc and -37vdc,
I know I can lower these voltages for the preamp if necessary.

I would like to put a preamp in the same box, lots of room.   Just wondering what  I should use for the front end.  I am making a bass amp head out of it.  Any input would be grateful!  I don't want something too complicated, but I do want a good sound for the bass.

Thanks!
Arn C.

Any suggestions?

[Gringo]

Hey Arn, have you seen this one?

http://www.albertkreuzer.com/electronics.htm#preamps

Take care!

[Arn C.]

Thanks Gringo!
Anyone else have any ideas, I really don't want it to be too complicated , just want a nice easy clean bass preamp.  
Thanks again!
Peace!
Arn C.

[smoguzbenjamin]

I'd say a FET buffer, then a FET or opamp gain stage to compensate the volume loss of the tonestack that comes after it, another buffer and into the power amp. Something along those lines should do great.

[Arn C.]

Thanks Smoguzbenjamin for your suggestion!
Peace!
Arn C.

[Kleber AG]

Hello Arn...
If you really want SIMPLE, but still powerfull this is a great tool I've been sucessfull using over an year now:
http://www.geofex.com/circuits/Adjusticator.gif

If you want you can start with simple buffer at input followed by a tone stack that you like and then feed this amazing circuit...

It'll provide lots of volume and really drive your power amp well.

Another  :lol: cool feature of this circuit is that you can plug straight to the speaker cab (in my case 4x12) and have nice practice amp for bedroon levels, for me it's so loud for home.

Thanks RG for this powerfull circuit (simple)  

Hope it helps...
Kleber AG

[Lonestarjohnny]

Arn, Why don't you pick out a Bass amp that has the EQ that you think would be useful for your style of playing and take the ROG way and put a J-Fet preamp in it, say like a Fender Bassman, or an SVT ampeg, or whatever, maybe 2 or 3 Emulater's on the front end with a footswitch controlling all 3 or 4, the sky's the limit if you have plenty of room.
JD  :idea:  :idea:  :idea: