Macbeth Micromac as a Drum machine
The Micromac-D by Ken MacBeth is a small and powerful, full analog standalone desktop synthesizer such as the eurorack module Micromac-R now including the Kenton MIDI-Interface and some extra features. Unlike his competitors it has three voltage controlled oscillators and a classic Moog lowpass filter, as a tiny desktop synth it could become indeed the bonsai-version of the M5 as the true MacBeth synthesizer!
The desktop version of the Micromac has not just CV and gate inputs to play the synth, but also a MIDI/CV interface from Kenton, who stand for very reliable and stable interfaces… and a few news with the additional LFOs.
3 VCOs: VCO1 and 2 have saw, pulse, triangle and sine waveforms and the pulse width can be voltage controlled by external CVs. A low frequency noise with level control is available as well. VCO 1 can hard sync VCO 2. VCO 3 can be used as a modulation oscillator and can be disconnected from the master CV. Modulation targets are filter cutoff frequency and/or pitch of VCOs 1 and 2. All VCOs have individual outputs, coarse and fine frequency controls, separate CV inputs for controlling frequency and pre-filter level controls.
The filter is a Moog 24dB lowpass filter. It´s input is a mixture of all three VCOs and noise. The cutoff frequency can be controlled by the first envelope generator as well as by an external CV. The filtertracking is switchable between off / half / full.
The envelopes are ADSRs with a switchable release parameter thats time is depending on the decay parameter, just like the Minimoog. The filter envelope can also be used to control VCO2´s pitch what sounds great when VCO2 is synchronised. Furthermore you can invert this envelope´s characteristic. The second envelope modulates the VCA. If an external CV is patched to the VCA the internal modulation is broken up. A momentary button allows manual triggering of the envelopes.