Component
CV math
v0.5.108
Does sums with control signals: adding and scaling.
Software v0.5.108
Overview
Does sums with control signals: adding and scaling.
A small calculator for control voltages. In Sum mode it adds up to three inputs, each with its own gain, plus a fixed offset: use it to scale a signal, turn it upside down (negative gain), mix two modulators or shift a CV up or down. In Mult mode it multiplies A by B, for example an envelope times the key velocity, so harder notes open the VCA further.
The gains run from −2 to +2, so you can also boost a weak signal.
Controls
| Control | Range | Default | What it does |
|---|---|---|---|
| Mode | Sum / Mult | Sum | Sum adds A, B, C and the offset; Mult multiplies A by B. |
| Gain A | -2 … 2 | 1 | How much of input A counts. |
| Gain B | -2 … 2 | 1 | How much of input B counts; in Mult mode 0 gives silence. |
| Gain C | -2 … 2 | 1 | How much of input C counts (here often pressure or the LFO). |
| Offset | -5 … 5 | 0 | A fixed value added to the sum (Sum mode only). |
Ports
| Port | Direction | Signal | What it carries |
|---|---|---|---|
| A | in | cv | First input. |
| B | in | cv | Second input; the multiplier in Mult mode. |
| C | in | cv | Third input, used in Sum mode only. |
| Out | out | cv | The result, limited to ±10 in Sum mode. |
How it works
Sum: out = A × Gain A + B × Gain B + C × Gain C + Offset, limited to −10 … +10.
Mult: out = (A × Gain A) × (B × Gain B). Input C and the offset are not used. This is a true product: with Gain B at 0 the output is 0 (silence), not "A without B". With envelope × velocity, Gain B above 1 lifts soft notes and below 1 makes the whole thing quieter.
The module has no memory and no timing of its own; it computes the result every control tick (1 kHz).
Runs on
- Teensy 4.1 (the MusicBrain Brain): less than 0.1 % CPU per instance, measured on firmware 0.5.108.
- The browser: the editor's simulator runs the same C++ code as WebAssembly, so what you hear while patching is what the Brain plays.
Try it
Patches to play (open them in the editor from their page): 6-stemmig ladder-filter.
In the editor's example set: 1-stemmig (mono), 2-stemmig, 4-stemmig, 8-stemmig, 16-stemmig, 4-stemmig + aftertouch → filter, 🎺 CS-80 brass (aftertouch), 🎹 Axel F-lead (2 saws), 🎧 Sampler ×8 (cellen), 🎧 Sampler ×8 auto-wah, 🎧 Sampler ×8 auto-wah + FET, 🎧 Sampler ×8 + EQ + Vari-mu, 🎺 CS-80 brass ×4, 🎸 Axel F lead.
Editor: https://editor.musicbrain.nl
Sources & licences
- Our own code, MIT licence.
Versions
- July 2026: in Mult mode the gains of A and B apply as well.
- 0.5.6: first version, used for velocity × envelope in the poly patches.