[sdiy] Thanks Everyone! (say, any CA3094's out there?)

[Magnus Danielson]

From: "Tony Allgood" <oakley at techrepairs.freeserve.co.uk>
Subject: Re: [sdiy] Thanks Everyone! (say, any CA3094's out there?)
Date: Sat, 23 Mar 2002 10:59:57 -0000

> >So well, now I'm wondering if it's possible to wire-up my own CA3094
> equivalent circuit onto an 8-pin dip header...
> 
> As far as I can tell, the 3094 is 'just' a 3080 with a NPN darlington
> follower on its output. In other words its half a 13600 without the
> linearising diodes at the front end.

In principle yes, but the internal solution differes between the 3094
and the 13600, I have compared them! Now, this should not be a
monumental difference, but migth be important in some cases.

> You could therefore make a little
> board to fit in. Basically, one 3080, two BC549s (or SM equivalent) and
> a resistor.

Actually, two resistors, a 2 kOhm resistor to the collector of the
first transistor, and then a 47 kOhm resistor between the base and
emitter of the output transistor. Both the emitter and collector of
the output transistor is outputs.

I've compared the CA3080 and the CA3094 schematics and the OTA side
are exactly equalent. So you can cook yourself a CA3094 from an
CA3080.

> Or use a surface mount 13700 and not use half of it.

Could be a good solution.

> If you do a search for the EH smallstone schematics you'll see the 3094
> used in a circuit.

Indeed. That is what made me learn about it. In some EH Smallstones
they are customlabel EH1048.

> I think the Moog 12-stage phaser used 3094s too.

... and there is more...

Cheers,
Magnus