Overview

This dual-purpose module combines a 3-input control signal mixer, with a multiple-input signal scope for viewing control signals.

Mixer

The control signal mixer has three inputs, labeled A, B, and C. Like an audio mixer, there are controls for level, mute and solo. When used with control signals, the level control acts as a scaling factor from 0.0 to 1.0.

Mixing happens in two stages, first inputs A and B are combined, then the result is mixed with input C. You can pick the operation used to combine signals at each of the two stages, either addition (mixing) or multiplication (ring mod). This may sound very unusual at first, but for combining control signals, multiplication is often more useful than addition. For instance, when mixing a pair of gate signals, add them is just like saying "This gate or that gate", whereas multiply is like saying "Only when both gates are open". Quickly switching between the two operations is useful performance control, thus the inclusion of this feature within the mixer rather than separately.

The mixer has one output, the main mix of all three inputs.

Scope

The scope can read from 6 different sources : inputs A, B, C (all of them before level, solo and mute controls), the mix of A and B, the mix of all inputs, or an Auxiliary input.

The update rate or speed of the scope can be adjusted from a rate of every 10ms to every 100 ms. Similarly, the range of the scope can be adjusted to match the range of the input signal. For instance, to match a pitch range varying from -12 to +12 semitones, set the range to 12.

Though the auxiliary input appears beneath the mixer inputs, it is not part of the mixer, it acts merely as an extra input to the scope. It can be used to monitor any control signal output by any module. In particular, it is handy when setting up a signal processor module to run after the Mixer. For example: Patch the input of two sequencers into the mixer, then patch the output of the mixer into a Signal Proc module. If you then patch the output of that module back into the Aux input of the Scope, you can set the scope to view the output of the Signal Proc module.

This scope is not completely accurate. In particular it will be slightly inaccurate for values that change very rapidly. For instance, when viewing gate signals (which are phase-modulated sawtooth waves), the amplitude of the sawtooth peaks will seem to fluctuate randomly. This is merely the result of the scope under-sampling the input signal. A fix for this will appear in a future update.

Parameters

Level A
Level B
Level C
Level adjustment (scaling) applied to each input, ranges from 0.0 to 1.0.

Mute A
Mute B
Mute C
Mutes the respective input.

Solo A
Solo B
Solo C
Solos the respective input, i.e. mutes all non-soloed inputs.

Mix Op AB
Selects the operation used to combine inputs A and B, either add or multiply.

Mix Op ABC
Selects the operation used to combine the AB mix with input C, either add or multiply.

Scope Rate
Sets the update rate of the scope, ranges 10ms to 100ms.

Scope Src (Source)
Selects the signal source displayed by the scope. Values are: Inputs A, B, C (pre level, solo mute) the AB sub-mix, the main Mix, and the Auxiliary input.

Scope Range
Sets the vertical range of values displayed by the scope. The center value of the scope is always 0.0. This control sets both the maximum and minimum visible values.

Aux Input
Auxiliary input the scope can be set to display.

Ports

The three main input to the CV mixer.

An auxiliary input that can be viewed with the scope.

This is CV output for the CV mixer.