Voltage Controlled Linear Crossfader, VCA, 4-quadrant multiplyer, and mixer

Caviar

Voltage controlled CAV.

A multifunction module of 2 halves. One half can:
- Linear Crossfade
- 4 quadrant multiply
- 0-10V VCA
- Bipolar Voltage Source
The halves are joined with some clever normalisation and a mixed output which unlocks all sorts of possibilities!
More details available here

What does it have?

• 2 Active Linear Voltage Controlled Crossfader Units with independent and mixed outputs.
• DC coupled inputs
• Active output buffers with anti-drooping short protection with 1k output impedance
• 45mm LED offset sliders with centre detent for tactile control and blinkenlights

How to Use It

A unit linearly crossfades between inputs A and B and expects a CV range between 5V (for 100% A), -5V (for 100% B). Larger voltages will continue to amplify the relevant signal but is likely to start saturating or have non-linear gain.

The CV offset slider provides for the full +-5V range.

Input B is normalled to the inversion of A. when nothing is patched in the unit simply crossfades between A and -A which is a 4 quadrant multiplier! The slider includes a centre detent which should be around 0V with tuning - this lets you use it like a VCA with unipolar CV but please accept eliminating all noise is impossible

If you patch something into B but leave it unconnected (or grounded) you create a cleaner linear VCA with unity gain at 10V.

A of the first unit is normalled to a 5V reference. yielding a +- 5V CV source when nothing is patched in.
patching into only B get's you a weird attenuating offset which could be useful!

A of the 2nd unit is normalled to A of the first for parallel processing. Self patch the output of the first into the 2nd for sequential processing

Specs

• Width: 6HP (30.48mm)
• height: 3U (128.5mm)
• depth: ~40mm (stack of 2 PCBs with stackable header which can be trimmed)
• +12V: ~50mA (TBC)
• -12V: ~50mA TBC (TBC)

https://softsynthetics.com/Caviar

• 50 mA +12V
• 50 mA -12V
• 0 mA 5V
• 40 mm Depth

Available as an assembled Module and as a DIY project.

This Module is currently available.