Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: monfi on August 19, 2018, 09:46:48 AM

Title: stereorama 2000 Deluxe into Guitar amplifier
Post by: monfi on August 19, 2018, 09:46:48 AM
Hello, I want to modify this amplifier that i bought in a flea market into a Guitar amplifier, is a full germanium transistor, that work at 9/12 volt . Is stereo so i'm thinking about use One Channel for high input and one for low, but i wanna drive only one speaker. Can help me for modification? Tnx
Title: Re: stereorama 2000 Deluxe into Guitar amplifier
Post by: Jazz P Bass on August 20, 2018, 12:33:21 PM
I am not too sure but it appears that there is a RIAA circuit at the inputs.
It's a compensation circuit for the phono pickup.
That will affect the input as far as a guitar goes.

Could you elaborate on "only want to use one speaker'.

I would not try to bridge the two output circuits.
Title: Re: stereorama 2000 Deluxe into Guitar amplifier
Post by: monfi on August 21, 2018, 03:06:28 AM
For "i want use one speaker" I mean bridge it like first image, if is not too much complicated. If it is too much complex i only wanna use only one channel at time but drive only one speaker.
I've found a more resolution schematic (2nd image) and first stage is only the EQ.
So, I hope in weekend I found some time for try to connect guitar and a speaker and try it.
Title: Re: stereorama 2000 Deluxe into Guitar amplifier
Post by: Jazz P Bass on August 21, 2018, 12:26:39 PM
I am of the opinion that you should not attempt to bridge the amps together.

See that triangle with the -1 in it?
That is an inverted signal as compared to the Left channel input.
If you want to try to cobble up a circuit for that, be my guest.