New tri-VCO design

Ian Fritz ijfritz at earthlink.net
Sun Jul 23 20:02:46 CEST 2000


Hi Jim and list --

The THAT120 looks like it should work pretty well. Did you ever try
measuring the matching?

Does anyone have a handy way to translate transistor matching specs (hfe,
hfe matching, Vbe matching, whatever) into current-mirror errors? Don't
remember ever seeing this.

  Ian


----- Original Message -----
From: "patchell" <patchell at silcom.com>
To: "Ian Fritz" <ijfritz at earthlink.net>
Cc: <synth-diy at node12b53.a2000.nl>
Sent: Sunday, July 23, 2000 10:55 AM
Subject: Re: New tri-VCO design


>     Pretty nice.  I am tempted to send you a THAT120 to substitute for the
> MAT03 and 2n3906 in your current mirror.  I would be currious to know if
one of
> these works just as good.  I am not positive, but I think the THAT120 is a
lot
> cheaper (but not as well matched as the MAT03).
>
> Ian Fritz wrote:
>
> > Hi all --
> >
> > Following interesting suggestions from Rene and Martin, I have put
together
> > a new tri-VCO using analog switches for current and threshold reversal.
> > Check it out at my site under wind synth circuits, VCO 2.
> >
> >   Ian
> >
> >   http://home.earthlink.net/~ijfritz/index.htm
>
> --
>  -Jim
> ------------------------------------------------
> * Visit:http://www.silcom.com/~patchell/
> *-----------------------------------------------
> *If you didn't buy a home in Santa Barbara,
> * You didn't pay enough!
> ------------------------------------------------
>
>
>




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