The MOTM-420 is a switch-selectable LP/NF/HP
(lowpass/notch/highpass) voltage-controlled filter. Using the same
filter structure as the MS-20, the MOTM-420 has a unique "cutting"
sound that is perfect for techno, acid, house, and other dance
music. The VCF will over-drive/distort in all modes, and the
resonance can be cranked into self-oscillation. The LP/HP slopes are
-12dB/oct and the NF is -6dB/oct.
The MOTM-420 includes 2 on-board 3-channel mixers: one for audio
and one for control voltages. This eliminates the need for a
separate mixer module in most patches. Multiple MOTM-420's can be
chained in series to exactly emulate the MS-20 filter (a HP followed
by a LP).
Unlike the more common 4-pole LP filters, the MOTM-420 has a
brighter, "glassy" sound. This is due to the selection of parts
used, and the filter design. The VCF will alter it's resonance as
the input amplitude varies. This was a "flaw" in the original
design, but is the main reason for the sound!
The MOTM-420 has 3 separate audio inputs, that can take audio
signals from any other synth, drum machine or sampler. By using a
"direct box", you can run a guitar or bass through it. Use a
voltage-out pedal for sweeps as you play.
Only average in difficulty, the MOTM-420 is a unique module that
can be finished in 1 day's time.