- controls the cutoff frequency
- controls the resonance
- controls how much FM1 influences the filter cutoff frequency
- controls how much FM2 influences the filter cutoff frequency
- In 1
- controls the level of input 1
- In 2
- controls the level of input 2
- In 3
- controls the level of input 3
- Mode (BP/LP/HP)
- selects the filter type: low-pass, band-pass, high-pass.
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.