DiY 808 question

[Fraser, Colin J]

> -----Original Message-----
> From: DCMagnuson at aol.com [mailto:DCMagnuson at aol.com]
> Sent: 09 March 1999 22:02
> To: synth-diy at mailhost.bpa.nl
> Subject: DiY 808 question
> 
> I've just decided to build myself a few modded 808/606 drum 
> sounds (kick and
> snare to start with).  My question revolves around op-amp 
> selection for the
> twin-T network.   The 606 appears to use JRC2904, and the 808 
> seems to use
> 4558's.  Is there any specific specs to watch for when 
> choosing an op-amp in
> this circuit?
> 
> Also, how about the transistors?  Will the usual 3904/3906 
> work in this
> circuit?

Just about anything will work in these circuits.
I used TL07x, BC184L and BC212L throughout my 808 clone circuits. I'm sure
3904/3906 will be just as good.

One thing to watch for with the 808 toms and bass is that you keep the pots
controlling your twin-t networks physically close to the circuit.
These circuits just love to pick up mains hum and boost it nicely...

Colin f