Selecta

This module has 4 channels of OR Combiner and 4 channels of A/B Switch.


The OR Combiner is conceived to select or sum trigger and/or gate signals, each channel has 2 inputs (A & B) and one output. A switch select which signal would be present at output, being the middle position of the switch the sum of both. It could be used with other type of signals but only the positive part of these would be present at the output stage (with a small lack of voltage because of the diodes and the pulldown resistor), so it could work with envelopes for example. With bipolar voltages the OR COMBINER channels will work as a Half-wave rectified output (the negative half of the signal is clipped to 0V) This can add many harmonics to audio signals.

The A/B Switch selects between A and B and the middle position of the switch is a "mute", works with any kind of signal (cv or audio) and is bidirectional, so it works in both directions. Can be used with 2 input signals and 1 output or 1 input signal and 2 outputs.

Easy build with 0805 smd passives (only a few)


  • This module does not draw any power.


Bill Of Materials:

R1, R3, R5 & R7 Are pull-down resistors. For most applications those resistors are not required, as the input load of the following module acts as pull-down resistor. But they should be added to be on the safe side. DOEPFER suggest a value of 10k, but with 100k you get smaller voltage drop.