# 1184 quad mixer vca (AKA 1183) **URL:** \ **Category:** KOSMO MODULES\ **Created:** [March 27, 2020, 2:27pm UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455 "2020-03-27T14:27:11Z")\ **Posts on this page:** 1\ **Showing post:** 38
**Author:** ![antoine.pasde2](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/antoine.pasde2/32/326_2.png) [@antoine.pasde2](https://lookmumnocomputer.discourse.group/u/antoine.pasde2)\ **Post date:** [May 29, 2020, 6:28am UTC](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455/38 "2020-05-29T06:28:31Z")
> [@fredrik](#): > > I don’t see what the diode is doing there; seems to me you could just leave it out… Yeah, the 2V Zener doesn’t seem to serve any purpose where it is. @lookmumnocomputer is it possible you meant to put it on the linear control voltage input instead of the signal input? > [@fredrik](#): > > The output is also a little bit odd Indeed. > [@fredrik](#): > > The first 100k doesn’t really do anything, what I can tell (after turning on some more braincells), since the current doesn’t have anywhere else to go but through it. You could probably use any value there. Or a 0 ohm link. The datasheet that I have says “Current Outputs Capable of Swinging to Within 1,5V of Each Supply” so that first 100k resistor would limit the maximum output current to ±10.5V/100k = ±105µA so input signals above ±105µAx47k=±4.9V will get truncated at higher VCA gain settings. So as you say @fredrik the first resistor would better be replaced by a 0 ohm link (anything below 1k would probably have very little detrimental effect). --- _[View the full topic](https://lookmumnocomputer.discourse.group/t/1184-quad-mixer-vca-aka-1183/455)._