THREETOM

Today, ThreeTom Modular is releasing the “Steve’s MS-22 dual VCF” module for eurorack.

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. 

The MS-22 contains two dedicated filter circuits, one low-pass and the other a high-pass. These are configured in series, the high-pass going into the low-pass. This configuration allows a unique duophonic fighting resonance behaviour (see the demo video below). The cutoff frequencies of both filters can be CV’ed. Compared to most bread-and-butter MS-20 clones, the MS-22 is twice the amount of filter condensed down into half the package (4HP).

Furthermore, the MS-22 also has the following unique selling points :

• The MS-22 has a unique modulation matrix that allows to configure many internal patches without using cables. Simply put, the modulation matrix (12-14) lets you route whatever modulation source you have connected to the ACV (auxiliary) input (e.g. an external envelope, LFO, S&H etc) to any or all of the following: HPF cutoff frequency, resonance amount, and input gain amount, either inverted or not
• The MS-22 has a unique link switch, which links the cutoff frequencies of the low-pass and high-pass filters in two different ratios. This creates two flavours of band-pass filters, of which the bandwidth can be tweaked and CV’ed. The switch itself also serves as an awesome performance effect as you can use it to create an instant drop. I demonstrate this near the end of this video.

Steve’s MS-22 is built to order in limited batches, the current batch consists of 10 units. Fully assembled modules are available for 225 EUR (excl. shipping). A limited number of DIY PCB+panel sets are available for 50 EUR (incl. shipping). 

More information (videos, specs, manual) can be found on the product page. Orders can be placed over e-mail, as described here.

ThreeTom Modular is a small boutique shop based in Belgium, run by Tom Verschooten, as a “hobby that go out of hand”, parallel to his full-time job as an Electronics engineer.

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”)

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.

As a follow-up to my previous post I will show how to convert the sample pack of Music Thing’s Radio Music so it can be used with the Erica Sample drum (or any other sampler). You can find the download link for the converted sample pack at the bottom of the post :)

In this post, I will show you how to do a batch conversion of whole sample packs (e.g from MusicRadar) into the right format for the Erica Sample Drum by combining Sox and shell scripting.

I have received new and revised prototype PCB’s for Steve’s MS-22. Next week, I am planning to assemble these in between going to see Gregory Porter at Gent Jazz and Neil Young at the Sportpaleis in Antwerp (good times ahead!). In addition to the PCB’s, I also had new front panels manufactured in a sleek matte black finish. In the picture below you can get an impression of what the final product will look like. Stay tuned!