ABC is a simple 6 channel signal mixer. It has 6 inputs – A, B, C, D, E, and F – and two outputs – A+B+C – which is mixed into the D+E+F output if nothing is inserted in the A+B+C jack. ABC is designed to mix audio signals but can be modified to mix CV signals instead. There are 6 solder jumpers on the backside, which can be connected to turn the ABC mix into a CV mixer.

Simple yet versatile: ABC mixes mono, stereo, or CV signals
There are also 3 jumpers on the backside which can be used to normalize inputs A to D, B to E, and C to F. This is useful if you would like to use the ABC mix as a 3 channel stereo mixer (using both outputs and having separate volume control for left and right channel).

Features
6 channel mixer
6 inputs A,B,C,D,E,F
2 outputs A+B+C and D+E+F (A+B+C is mixed into D+E+F if no jack is inserted in A+B+C)
3 jumpers to select normalization of inputs A to D, B to E, C to F (useful for stereo mixing)
inputs are AC coupled
there are solder jumpers for changing the inputs to DC coupling (than it can be used for mixing CV signals)
front panel from aluminium or oak wood
handmade locally by Bastl Instruments in Brno, Czech Republic
Technical details
5HP
35 mm deep (skiff friendly)
current: +12 <10mA, -12 <10mA
PTC fuse and diode protected 10 pin power connector