Available as an assembled Module and as a DIY project.
This Module is currently available.
Utilitarian audio and CV mixer
Combine up to four audio and or CV sources into one output, with independent manual level control.
It can be used as a four-channel mixer or as two separate two-channel mixers, depending on the connection.
If a cable is connected to the Master output but not to the 1+2 output, all channels will be summed at the Master output. If both the Master and 1+2 outputs are connected, the Master will output the mix of channels 3 and 4, while the 1+2 output will provide the mix of channels 1 and 2.
Each pair of channels has an LED indicator that shows the presence of a signal.
FEATURES:
Dual Sumimg topology.
DC Coupled.
lLED Signal Indicators.
These merchants probably sell this module. Huh?