The ASM-2 VCA Module
Introduction

VCA
ABOUT
How
Setup
Schematics VCA 1 VCA 2
WiringVCA1VCA2

The VCA can be used in conjunction with the ADSR module for dynamic control of signal amplitude, and also for periodic amplitude modulation of the signal waveform (tremolo).

This module uses the CA3080 as the voltage controlled gain device, driven using a trick originated by Walter Jung and documented in Electronotes. It has a linear control voltage/amplitude response.

 

The unit has the following features:-

Specifications:

  • Linear voltage control/amplitude response

Connectors:

  • Control inputs (3)
  • Signal inputs (2 - 1 x +ve and 1 x -ve)
  • Output

CREDITS

Walter Jung
"Application of the Two-Quadrant Transconductance Amplifier/Multiplier in Audio Signal Processing"
Journal of Audio Engineering Societry
Vol. 23, No. 3, April 1975

Bernie Hutchins
"The ENS-76 Home-Built Synthesizer System - Part 1"
Electronotes, Vol. 8, No.63, Mar. 1976, pp 2-8

Email:  elby_designs@ozemail.com.au
Copyright 2000. All rights reserved.     Revised: June 17, 2008