Book

Circuit Atlas · HUSH M4 · Rev 2027.4 draft

S5 Channel fader (control-voltage VCA)

Schematic for S5 Channel fader (control-voltage VCA). Design targets and calculations, no measurements.

IN DEVELOPMENT · REV 2027.4 (DRAFT) · DESIGN TARGETS, NOT MEASUREMENTS

HUSH M4 is in development. This draft is published on zakkhutoretsky.com; it has no price and no ordering. Figures marked design target are goals for the finished product. Figures marked calculated come from the published formulas. No value on these pages was measured on a built unit. Interviews are cited as the design brief, not as an endorsement.

See this control Channel fader on the playable panel

S5 Channel fader (control-voltage VCA)

Channel fader as a control-voltage VCAA 10 kilohm linear fader pot between a 5 volt reference and ground sets a control voltage. A scaler brings it to 0.6 volts, which drives the control port of a generic exponential VCA. Audio never passes through the fader. The crossfader bus is not fitted.S5 CHANNEL FADER — control-voltage VCA (no crossfader fitted)+5 V REFP710k lin 60 mm−+U6bufferRt47kRbt6.49kEc+ 0 to 0.61 Vcontrol portAUDIO INRa10kVCAgeneric exponential−+U7I-to-VRf10kTO SUM BUS AND CUE TAPVCA control constant 6.1 mV/dB (THAT 2180-series datasheet): 100 dB range needs 0.61 V; scaler 47k / 6.49k gives 0.607V from the 5 V reference. Rin = Rf = 10k sets 0 dB at full travel. Pin-out and bias come from the chosen VCAdatasheet.
S5 Channel fader (control-voltage VCA) (schematic) Swipe sideways to pan on a phone.
ItemValue / formula
LawVCA control constant 6.1 mV/dBR8: 100 dB range needs 0.61 V
Control pathP7 10k linear fader on a 5 V reference → buffer → 47k / 6.49k divider → 0.607 V maximum
Audio pathRin = Rf = 10k sets 0 dB at full travel; the audio never passes through the fader
CrossfaderNot fitted, as stated on the /mixer page (left out on purpose); a second control bus is a footprint option only

The mixerTechnical manualManual (PDF, 685 KB)Glossary

For music supervisors: sync licensing for film, TV and ads →