The Befaco Hexmix VCA DIY Kit is the self-build version of Befaco's six-channel Eurorack VCA. It fits six voltage-controlled amplifiers with adjustable response curves and a switchable mixer into 14 HP. It suits builders who want several VCAs and a compact mixer in one module, either on its own or as part of Befaco's Hexmix system with the Hexmix and Hexpander.
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Six VCA channels: each has a signal input, CV input, output, response control and level control.
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Variable response: per-channel control from fully exponential at minimum, through linear at centre, to fully logarithmic at maximum.
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Post-VCA level: each channel's level control attenuates the signal after its VCA.
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Normalled CV: an unpatched CV input defaults to 10 V, which holds the VCA fully open so the level control acts as a volume knob.
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Switchable mixer: sums all six channels at output 6, and patching a channel's output removes that channel from the mix.
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Complete kit: includes all parts for a finished module, plus a power cable and four Befaco Knurlies M3 rack screws.
The response control changes how each channel reacts to control voltage. Befaco's manual describes linear as the setting that preserves a signal's natural dynamics. Exponential gives smoother control and works well with modulation sources, at the cost of some dynamics and gain. Logarithmic is the aggressive setting, with a strong attack and sharp decay. Use it for hard-hitting percussion or for realistic audio crossfades. Because the curve is set per channel, one module can shape a percussive envelope on one channel and handle gentle modulation on the next.
A switch at the bottom right sets mixer mode. With the switch on, output 6 carries the sum of all six channels. With it off, channel 6 works as an independent VCA. Any channel can be taken out of the mix by patching a cable into its own output, while the rest stay in the sum. An expansion port on the back links the module to the Befaco Hexmix. Keeping channel 6 independent is handy in that setup.
Channel inputs accept signals up to ±10 V, the CV inputs expect 0 to 8 V, and outputs reach up to ±8 V. The front panel is heat-treated aluminium. The module was designed in Barcelona, where the kits are also prepared. Befaco publishes an assembly manual, schematic, parts list and interactive build guide for the kit.