The AttenuVerter is an double channel CV processor. It is capable of attenuating, inverting and offsetting two independent Control Voltages.
I already published about a single “chicklet” Attenuator – Inverter. But this time, it’s a full featured module, in 4 HP width front panel, with jack connectors, and the addition of an offset potentiometer per channel.
The circuit is slightly more complex as there’s now 3 op-amps per channel instead of just one. As the two channels are strictly identical, I 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 on input jack socket 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 properly the bi-color LED D1.
The processed CV is then sent, through protection resistor R12, to the output jack socket J2.