Doepfer A-135-4B

This module is used to route the 16 external control voltage to the main module A-135-4A. These control voltages are available for each channel:

• Level (main loudness)
• Panorama
• Aux
• Mute

For each control voltage an input socket and a polarizer control are available (the polarizer function is described more detailed on the A-138c info page). That way it's possible to adjust the depth and polarity of the external control voltage which affects the parameter in question. If the same CV (e.g. LFO or ADSR) is used e.g. for two panorama control inputs the result may be the opposite if the polarizers are adjusted accordingly (i.e. one positive and the other negative). The external control voltage is added to the voltage that is generated by the manual control on the A-135-4A main module. The sum of both voltages is used to control the VCA in question and is displayed with the corresponding LED on the A-135-4A module.

The mute CV input works in principle in the same way as the level CV input but with reverse polarity and higher sensitivity. Typically the mute polarizer control is adjusted fully CW. Then a (gate) voltage of ~ +2.5V or more fully mutes the channel in question.

A-135-4A and A-135-4B are connected internally via a 20 pin ribbon cable. The cable can be longer so that the CV input module A-135-4B needs not to be mounted next to the main module A-135-4A (e.g. to the row above or below).

Modules A-135-4A and A-135-4B are available only as a module combo because the single operation of each module does not make sense !