component substitution

Jim Patchell patchell at
Thu Nov 4 16:03:07 CET 1999

    The AD821 & AD818 can be replaced by the MAT03 and MAT02 (formally PMI
parts, now Analog Devices).  The CA3140 is commonly avaliable.

    Also, at my web site, I have a list of parts that are commonly used in
synth circuits and where to get them.


Steve Wegner wrote:

> Hi, I'm new to this list and to synth building as well. I'm working on
> an analog design based on some of the basic module schematics from Hal
> Chamberlin's "musical applications of microprocessors" (they originally
> appeared in Electronotes Newsletter). I've managed to round up most of
> the parts(or equivalents), but am having trouble with a few:
> Transistors----AD821 & AD818 matched pairs (pnp & npn, respectively)
>                         2N3819
> OP Amp -----CA3140 (BIMOS)
> and last but not least, the elusive Q81 temperature compensating
> resistor (-0.33%/degree C)
> If anyone could tell me anything about these parts or their equivalents,
> it would be greatly appreaciated.
> Thanks,
> SdUB

More information about the Synth-diy mailing list