The AttenuVerter is a dual-channel CV processor. It can attenuate, invert, and offset two independent control voltages.
I already published about “chicklet” Attenuator – Inverter. This time, however, it’s a full-featured module on a 4 HP wide front panel, with jack connectors, and the addition of an offset potentiometer per channel.
The circuit is slightly more complex, as there are now 3 op-amps per channel instead of just one. Since the two channels are strictly identical, I will only describe the first channel.
The first op-amp (U1A) is the most important, as it is responsible for the two main features of the module: inverting (or not) and attenuating the signal present at input jack J1. R1 sets the amount of gain. R2 and R3 modify the response of the potentiometer.
The second op-amp (U1B) introduces an offset voltage, set by potentiometer R7.
The third op-amp (U2A) isn’t part of the signal path. Its role is to drive the bi-color LED D1 properly.
The processed CV is then sent through protection resistor R12 to output jack J2.
