These modules are simple passive circuits, posted mostly for the panels in case anyone wants to build them but doesn't want to deal with designing a panel themselves. These modules are all unpowered.
This is an 8 channel on/off switch module. It works great for muting drum tracks by putting it in line with the trigger signal, but could be used to mute audio signals as well. Mount a jack in each of the outer holes, a switch in each middle hole, connect all the grounds, and solder each jack to one side of a switch.
A passive mult, probably the simplest module you could build. Mount jacks in each hole and solder all the tips and sleeves together.