A small mixer module for the After Later Audio 7U case. I chose the DC-S for its interesting design and functional characteristics.
We called this new mixer design a Combinator, and the name DC-S stands for Dual Combinator. This versatile mixer can function as a dual-channel, mixing up to 4 inputs into a single output, or as a single-channel, allowing up to 7 inputs to be mixed into a single output.
The first signal gets patched to the left-most jack. It is transferred with unity gain to the output. As subsequent signals are added, the gain of each is reduced proportionally, to keep the output inside a reasonable range. If every input is +/-5V, no matter how many inputs there are, the output mix will be +/-5V. If no signal is patched to the left-most lower input, the upper output is inserted there, as indicated by the face plate.
Assembly
I bought the kit from Modular Addict, where there was a choice between a PCB and Panel or a Full Kit. I went with the full kit because I like the Black Noise gold jacks. In fact the only thing extra with the Full Kit is the jacks. If you don’t care about gold jacks, skip the Full Kit and save yourself $30. As it happened, my Full Kit was missing two of the jacks! They sent the wrong jack set.
Kit showing jack bag for the DR II – S, a different product
But I had plenty of jacks on hand. And I like Black Bananuts on outputs.
All parts, including two of my own jacks with Black Bananuts
Assembly is straightforward. First, all the jacks are inserted into the PC board. Second, the panel is fitted over the jacks (quite tricky in fact). Third, fit the nuts to all the jacks. Fourth, turn the board over, insure proper seating of the jacks to the PCB and the panel and solder.
