Doepfer - A-132-8: Octal Poly VCA
A-132-8 is an octal VCA and primarily planned for polyphonic applications. The module contains four VCA pairs. Each pair includes two daisy-chained VCAs. One VCA has a linear control scale, for the second VCA linear or exponential control scale can be chosen by means of jumpers. We decided to provide two VCAs for each voice because usually one VCA is required for loudness envelope and a second one for velocity (or other functions like individual voltage-controlled loudness of each voice, amplitude modulation and so on).
These controls and in/outputs are available:
Default Gain 1 (GL)
Default Gain 2 (GX)
CV Input VCA 1
CV Input VCA 2
In addition an Audio Sum Output is also available.
The module features two Default Gain controls (GL, GX), that enable the opening of the first VCAs (L) and/or second VCAs (X). For this the controls GL and GX generate two internal control voltages 0...+10V which are connected to the switching contacts of the sockets 1L...4L (control GL) and 1X...4X (control GX). As long as no patch cable is inserted into the socket in question the internal default control voltage (GL or GX) is used to control the corresponding VCA. This is necessary when the VCA in question is not in use (i.e. no external CV available). Otherwise the VCA would close and there would be no output signal even if the other VCA in the chain is open. The controls GL and GX are also useful for testing polyphonic patches (e.g. for tuning the VCOs).
In the factory the CV inputs are adjusted for a CV range 0...+10V - matching to the polyphonic ADSR module A-141-4. But the sensitivity of each CV input can be adjusted by means of a trimming potentiometer to adapt the CVs even to other control voltage ranges.
Application:polyphonic patches with two VCAs per voice.