[sdiy] Which opamp pins wiring is best for CV out ?? A , B or C ???

Tim Daugard daugard at cox.net
Tue Nov 9 18:17:10 CET 2010

From: "Ian Fritz" <ijfritz at comcast.net>

> Part of the reason for 1k in synth circuits is so you can connect two
outputs together to add the signals. (But does anyone actually do this?)


Also use the 1k8 resitors I use on the output as parts of plugable filter 
networks. 1st stage uses output resistor and a cap - impediance approx. 2k 
Second stage uses resistors / caps with nothing active - impediance approx 
20k. This Feeds an input impediance of 100 to 200k. Each fliter stage is 
lightly loaded by the following, stage allowing plenty of passive shaping 
between modules. The filters are built into cables.

100R on the output would give me one more decade of impediance transforms. 
But lose the output protection so I stick with 1K. HOWEVER, I don't use 
accurate VCOs, Instead I use a fender bass as my primary signal source.

Tim Daugard
AG4GZ 30.4078N 86.6227W Alt: 12 feet above MSL
http://members.cox.net/synthfred/h_toctop.htm (Fred's online edition)

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