Welcome to Robot Dialogs. This is a place where I will record my progress, mistakes, errors, failures, lessons learned and hopefully occasional success in my designs and implementations of robots and other technical endeavors. I will try to make it as educational, informative and entertaining as I can...

Sunday, September 4, 2022

Eurorack Triple Attenuverter

This design is a variant of Befaco's Dual Attenuverter which I purchased from them well before I knew I wanted to build things like this myself. Their module is very useful and I recommend it. They provide their schematics with the creative commons license and markings. Help support them, buy their stuff! 

Befaco's (left) version and my own (right). I've removed the LEDs in my design and made it a bit wider to allow three to fit. Without the LEDs it still uses only 3 dual op-amps. 

This is just a utility module that allows the signal on the input to be inverted, scaled and offset. Very handy in my rig for taming the 10V CVs for use on 5V CVs or just as a general extra adjustment to various signals.

Here's a simulation.

12V Current: 16mA
-12V Current: 16mA 
5V Current: None

Issues on v1
 - R5 and C2 are swapped on silkscreen

Thoughts for v2:
 - Not much, but the LEDs would be nice if I can figure out a layout that allows them.

Design files for the PCB and Front Panel: https://github.com/EchelonForce/triple_attenuverter