[sdiy] CMOS as voltage variable resistor

[greg montalbano]

And don't forget the Korg MS-20 envelope generators.


At 01:21 PM 5/2/02 +0000, you wrote:

> >I think the cmos ic 4007 is used in a couple of adsr circuits ,
> >for example in the Arp omni and the Korg PS3200 .
> >but I'll have to look at the schematics to see if its used as a volatge
> >variable resistor.
>
>In the 3200, the 4007 is used as switch and inverter only.
>VC resistors are done with bipolar transitors and with LDRs.
>
>ARP used the 4007 for many applications, including VC resistors.
>(http://home.t-online.de/home/jhaible/hj_qph_1.gif - not the
>original ARP circuit, but the VC resistor part is used as in the
>original.)
>
>JH.