Precision attenuverter / mixer

Quad precision attenuverter / mixer

4 precision attenuverters and an integrated unity gain mixer.

The attenuverters have individual outputs, and the mixer takes its inputs from the attenuverter output jacks normal switches. Hence, by default the Sum output contains the sum of all attenuverter outputs. However, if a cable is plugged to an individual attenuverter output, that attenuverter is removed from the mix. Finally, there is a unity-gain Aux input to combine for example multiple mixing modules together.

Update August 2019: PCB version 1.1 is now available. It now features a 5V reference voltage, which is normalled to the first input jack. Hence, the first knob can be used as an offset voltage if nothing is connected to it's input. If desired the other input jacks can be also be connected to the 5V reference with solder jumpers on the PCB. The front panel layout has not changed with this revision.

https://kassu2000.blogspot.com/2018/04/precision-attenuverter-mixer.html