Available as an assembled Module and as a DIY project.
This Module is currently available.
Convertible 4 channels Lin/Log mixer with master attenuator and inverted output.
MIXER 4 is a 4 channels mixer but with extra features.
Each channels can be set individually as linear or logarithmic. Linear curve are more suitable for CV signals wherease logarithmic is use for audio signals.
MIXER 4 also feature a master attenator to control master volume. Master attenuator can also be set as linear or logarithmic. Finally MIXER 4 feature two output a mix output and a inverted copy of the mix output.
Now you don't have to mind about linear or logarithmic mixers. Just get MIXER 4 and configure it following you needs.
https://blacknoisemodular.com/products/black-noise-mixer-4-eurorack-module