My endeavour to make just a very simple line level mixer with at least 4 channels. I made multiple versions, DC coupled, AC coupled and with or without volume control and the need of dual or single power supplies.
#Simplest 4 channel stereo mixer
quiet trail
Features
- 4 stereo inputs, one stereo output
- Individual volume control
- Quite basic so also quite adaptable
TODO
- Build it on perf
- 3D print enclosure
In the end I will probably choose an AC coupled single supply solution without any form of volume control. Why? Volume control is on my modules already and the output will be fed to an audio interface with its own gain control.
crystal hawk
input stereo pots or sliders?
quiet trail
for my unit neither 
eternal kestrel
If you want to feed it to something else output volume might be useful. Or maybe a headphone amp why not