AI Synthesis Eurorack AI008 User manual

AI Synthesis AI008 Matrix Mixer
User’s Manual
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This is the Manual for the AI008 Eurorack Matrix Mixer you can purchase it by going to:
aisynthesis.com/product/ai008-eurorack-matrix-mixer.
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1. About the AI008 Eurorack Matrix Mixer
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If you are new to DIY electronics, this is a great second module to build. The first module, the
AI001 Multiple is ideal for beginners, as it teaches how to solder and signal flow. The AI008
Matrix Mixer familiarizes you with common electronic components, and is powered.
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The AI008 Eurorack Matrix Mixer is a compact 4-in, 3-out matrix mixer. A matrix mixer is used to
route audio or cv signals from multiple sources to different destinations. There are twelve
potentiometers, with each potentiometer controlling the amount a given input (1-4) will be sent
to a given output (A-C).
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The AI008 also contains a summed output of A+B+C. A common usage for the AI008 would be
as an effects send, with one or more inputs, and one or more effect inputs and outputs. Using
the AI008 Matrix Mixer in this way, inputs can be sent to multiple effects, and the effects can be
sent to each other, and even back into themselves, expanding the depth of the effects.
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2. AI008 Controls
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1. Input 1 Mixing Row. This row of knobs
controls the amount of signal from the Input
1 jack will be mixed to outputs A-C. A1
controls the amount of Input 1 that appears
at output A. B1 controls the amount of Input 1
that appears at output B. C1 controls the
amount of Input 1 that appears at output C.
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2. Input 2 Mixing Row. This row of knobs
controls the amount of signal from the Input
2 jack will be mixed to outputs A-C. A2
controls the amount of Input 2 that appears
at output A. B2 controls the amount of Input 2
that appears at output B. C2 controls the
amount of Input 2 that appears at output C.
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3. Input 3 Mixing Row. This row of knobs
controls the amount of signal from the Input
3 jack will be mixed to outputs A-C. A3
controls the amount of Input 3 that appears
at output A. B3 controls the amount of Input 3
that appears at output B. C3 controls the
amount of Input 3 that appears at output C.
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4. Input 4 Mixing Row. This row of knobs
controls the amount of signal from the Input
4 jack will be mixed to outputs A-C. A4
controls the amount of Input 4 that appears
at output A. B4 controls the amount of Input
4 that appears at output B. C4 controls the
amount of Input 4 that appears at output C.
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5. Inputs. These are the four inputs of the
Matrix Mixer. The amount of signal passed
from these inputs are controlled by the
Mixing rows.
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6. Outputs. These are the separate mix outputs. Each output controls a mix of Inputs 1-4 as defined
by the mixing rows. The A+B+C output is a summed mix of the A, B, and C outputs.
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3. Power
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The AI008 uses a shrouded header to prevent the cable being plugged in the wrong way. The unit
draws 17mA on the positive and negative side.
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4. Gain Staging
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The AI008 mixing stages are “unity” based, with the exception of the summed output. So if you have a
5V peak to peak signal at Input 1, and A1 is set to 100%, then Output A will be an in phase version of
that 5V Peak to Peak signal.
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In this picture, the Green and Blue waveform overlap completely. The Green is the signal before
going into input 1, at 5v peak to peak. The input is 100% for A1. The Blue wave is output A, perfectly in
phase, and at 5V peak to peak. The Red waveform is the summed output. In Phase but at about 2V
peak to peak. I designed it that way because that summed output is going to have a lot going on
most of the time, and I didn't want it to clip.
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5. Patch Ideas/Uses
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Feedback Patch
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In this patch, we are feeding effects back into themselves in order to create an ambient soundscape.
The effects are arbitrary, but having a Delay is important. The effects in this patch are a distortion, a
delay, and a reverb. Each is patched in, and out of the Matrix Mixer. Each output of A, B, and C can
have a mix of Inputs 1-3 (distortion, delay, and reverb) sent out of it back into the Distortion, Delay,
and Reverb. Start by mixing the delay into the delay until it feeds back into a squeal, and then back
off of the mix knob. Then start mixing in (and out) the other effects. This can be a wonderful way to
create cool transitions in a live environment. Input 4 could be fed from a mixer’s aux send, and when
one patch is done, a feedback patch could be created while a new patch is made.
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Feedback Oscillator Patch
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In this patch, two oscillators are fed into the AI008 Matrix Mixer. This patch should be doable with any
voltage controlled oscillator that has CV inputs. The outputs of the Matrix mixer are fed back into the
oscillators, with one oscillator getting a mix of signals fed back into its Frequency Modulation input,
and the other oscillator getting a mix of signals fed back into its Frequency Modulation and Pulse
Width Modulation inputs. The summed A+B+C output, could then be fed to a traditional filter/VCA

combo for a feedbacking mono synth patch, or patched out as a drone source, or out to anything as a
sound source.
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CV Feedback Patch
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In this patch, we are using the Matrix Mixer to feed voltage from voltage generators back into them.
In this case I’m using a Maths and a VCLFO, but this can be done with any CV controllable LFO,
Envelope Generator, or other Voltage Source. The ramp wave from the VCLFO is fed into Input 1
where it can be distributed to all three outputs (A, B, and C). A summed waveform from MATHs is fed
into Input 2 of the Matrix Mixer, where it can also be mixed to different outputs. The Output A mix
(which can contain MATHS and the VCLFO) is sent to the CVin of the CVLFO, creating a constantly
evolving voltage source there. Out B of the Matrix Mixer is sent to the Rise CV of Maths, and the Sine
output from the VCLFO is sent to the Fall CV input. With all of this CV madness, there are still two
inputs open on the Matrix Mixer with which to cause havoc.