Boredbrain Music Mimix

Dual Multiple & Unity Mixer

Mimix is a handy utility for copying and combining signals in eurorack systems. The module features three sections: two buffered multiples each with an augmented fourth output, and a 4-input unity summing mixer.

Features
- 1 to 4 buffered multiple with inverted 4th copy
- 1 to 4 buffered multiple with rectified 4th copy
- 4 to 1 unity mixer normalled to the two multiples
- Bipolar LED signal indicators for each section

Duplication
Mimix has two independent multiples, A and B, each with four available copies of either audio or CV. Unlike passive multiples, these buffered copies use active circuitry to ensure there is no signal loss or interaction between the signals.

Additionally, the input impedance is very high so the source signal is essentially unaltered, and precision components are used so that each copy is identical. This is necessary when copying voltages scaled to 1V/oct for pitch control of oscillators and sound sources.

The two multiple sections, A and B, each have two WHITE LEDs which help to visualize the strengths and polarities of the input signals.
Augmentation

Identical copies are ideal for many applications, but not necessarily for experimentation. For this reason, the fourth output of each multiple is an augmented copy derived from the source signal.

Multiple A has an inverted copy labeled A INV, which has its polarity flipped. When the source signal voltage is positive, this output is negative. When the source signal voltage is negative, this output is positive. This is useful for patching opposing modulation signals.

Multiple B has a rectified copy labeled B RECT, which outputs a full-wave rectified copy of the source signal that is always positive. When the voltage of the source signal is negative, the output is inverted. This is useful to control parameters which typically require a positive modulation signal, such as VCAs. It can also be used to distort audio signals, and much more.

Combination
The last of the module’s three sections is a 4-input mixer. The summing circuit combines all four inputs at unity gain to the SUM output. This is useful for creating interesting modulations or mixing several audio signals together to a single output.

By default, the first two inputs, [A] and [B], are normalled to the inputs of the two multiples. However, they may be replaced by plugging other signals into their respective input jacks. Inputs C and D are for additional external sources which can be added to the mix.

Similar to the two multiple sections, there are two WHITE LEDs to indicate the strength and polarity of the mixed signal at the SUM output jack.