ThreeTom Steve’s MS22 Eurorack Dual VC Filter Module

The MS-22 is a dual voltage controlled filter, inspired by the classic Korg MS-20 filter, with an innovative modulation matrix and one of the highest function-to-hp ratios in the land of Eurorack. This module was inspired by many pleasant chats with tech journalist Steve O’Hear.

The MS-22’s is different from most MS-20 inspired filters as it contains two dedicated filter circuits (instead of one), one low-pass and the other a high-pass. These are configured to be in series, the low-pass going into the high-pass. This configuration allows a unique duophonic fighting resonance behaviour. The cutoff frequencies of both filters can be CV’ed. So, compared to most MS-20 clones out there, the MS-22 is twice the amount of filter condensed down into half the package (4HP).

Features

• General
  • Dual VCF inspired by the Korg MS-20 OTA filter
  • Low-pass (12dB) into high-pass (6dB) 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

Specifications

• Width: 4hp
• Depth: 45mm
• Power: +100mA Max / -100mA Max

Manufacturer product page here.
Product manual here.