As the rev. 2 prototype of Steve’s MS-22 is nearing its final form, I am happy to release its specifications :

  • General features
    • Dual VCF inspired by the Korg MS-20 OTA filter
    • Low-pass into high-pass configuration
    • Innovative modulation matrix allows CV control over all parameters
    • Cut-off frequencies can be linked, resulting in a band pass filter with controlable bandwidth
    • Bipolar monitoring LEDS for the LP, HP, resonance and gain CV signals
    • One of the best functionality-to-size ratios in Eurorack with a width of 4 HP and a depth of 45 mm
  • Connections
    • Filter input
    • Filter output
    • Frequency CV input (FCV)
    • Auxiliary CV input (ACV)
  • Controls
    • LP cut-off frequency (“frequency”)
    • HP cut-off frequency / BP bandwidth (“spread”)
    • Resonance : from mild to screamy
    • Gain : from warm to asymmetrical saturation
    • LP Frequency CV (FCV) attenuator
    • Auxiliary CV (ACV) attenuator
    • LP-HP link switch : 0%, 50% or 100%
    • Modulation Matrix switches, routing ACV to HP cut-off / spread, Gain and resonance : +ACV, off, or -ACV (inverted)
    • Calibration trimmers for the HP and LP filter are available from the side of the module.
  • Modulation
    • Designed to work with unipolar +5V or bipolar +-5V modulation sources
    • Will also take unipolar and bipolar 8 and 10V modulation signals, but this results in a smaller usable range on the ACV and FCV attenuators
    • Low frequency and audio rate modulation of all parameters
    • Bipolar monitoring LEDs (green: positive, red: negative) for all CV destinations (LP cut-off, HP cut-off / spread, resonance, gain)
  • Construction
    • 4 HP wide
    • 45 mm deep (skiff friendly)
    • High quality aluminum knobs with grippy surface
    • 2 mm thick matte black front panel with white and metallic print
    • A tasty 4-layer PCB sandwich, containing 350+ components
    • Recessed power connector, avoids your power cable from adding to the module depth
  • Protection
    • Reverse power protection
    • Buffered high impedance inputs
    • Output is protected by a 1K output resistor
  • Power consumption
    • +12V : 100mA max
    • -12V : 100mA max

See the block schematic below (symbols as suggested by Bjørn & Meyers in “Patch & Tweak”)

Steve’s MS-22 filter topology
Steve’s MS-22 modulation matrix

I am currently working towards a demo video and hope I’ll be able to share that soon.

Subscribe to my mailing list and I’ll keep you posted about the development of this module and when it becomes available.

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