Synthrotek Intros MIDI-CV Expander & New Music Thing Modules

At Moogfest 2016, we talked with Synthrotek’s Steve Harmon, who showed us their new MIDI-CV Expander Eurorack module, and told us about a new series of modules, based on Tom Whitwell’s Music Thing Modular designs. 

MIDI-CV Expander Features:

  • Three note priority modes: high note, low note or last note
  • Arpeggiator: forward, ping-pong, random modes
  • Manual MIDI Reset Button
  • Volts-per-octave trimmer accessible from the front panel
  • Velocity, Modulation and Aftertouch CV output jacks function independently but can be
  • used simultaneously
  • Control the arpeggiator with a modular or MIDI clock
  • Pitch CV and gate outputs
  • Select MIDI channels 1-16 with an internal DIP switch
  • Gate / Note Priority LED indicator
  • Polarity protection


Update: Synthrotek shared these short video demos of the Expander in action:

Technical Details: 

This demos sending several channels of MIDI data from Ableton Live to the MST MIDI to CV Converter, which is then going to two Expanders., resulting in Zelda Dungeon through an analog MST System 104 synthesizer.

The Music Thing Modular modules are open source and Synthrotek will be selling modules with their own branding, based on the Music Thing designs. You can read about Whitwell’s take on open source synth modules at his Music Thing Modular Notes blog.

Synthrotek’s Euro module designs are available both pre-built and as DIY projects.

Check the Synthrotek site for more info.

11 thoughts on “Synthrotek Intros MIDI-CV Expander & New Music Thing Modules

    1. I haven’t heard anyone making a stink about this until now, so are you sure that buying them from Synthrotek isn’t also supporting Music Thing Modular? I feel like if it weren’t all above board, we’d be hearing a lot more about it….

      1. The modules are open source and there are already half a dozen companies making versions. Whitwell discusses this in his article about open sourcing it.

        So there is no doubt that this is ‘above board’ and suggesting otherwise is just wrong.

        The designs are shared with an Attribution-ShareAlike 3.0 license, which means:

        You are free to:

        Share — copy and redistribute the material in any medium or format

        Adapt — remix, transform, and build upon the material for any purpose, even commercially.

        The licensor cannot revoke these freedoms as long as you follow the license terms.

        Under the following terms:

        Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

        ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.

        No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

        Synthrotek’s responsibility is to give Whitwell credit and to share their derivative designs back to the community.

        You may still want to look for vendors that explicitly support Whitwell, but that’s your choice, not Whitwell’s.

        Kudos to Whitwell for taking such a generous approach – it’s very different than what most designers do.

      2. yeah, Tom is losing money from adopters like this. from comments i’ve seen online i think he’s starting to have serious doubts about the whole open source thing. i believe this will be the case with other open source designers, such as MI and 4ms, too, in the near future, now that the mass production of open source derivatives is ramping up.

        1. southpole

          It looks like you have figured out that forum comments are the most accurate source of information on the Internet.

          Good for you and thanks for sharing!

    2. I’d love to, but Thonk is the ‘out-of-stock’ online retailer. Above all others, when I go to Thonk, and find something interesting, they are almost always sold out. It’s really discouraging. I understand limited editions and small production runs, but I have never bought from them, because when I wanted it, they didn’t have it.
      Thonk is reputable, and sells cool things, but I, for one, am happy that there is a second source for the Whitwell stuff. Synthrotek is a reputable company too, but they seem to do a much better job keeping stock at reasonable levels, and they will help meet the demand for these designs.

  1. Hello Synthotek, will you be paying Tom a royalty like Thonk does? If so I’m interested. You panel designs look very good.
    I understand Tom released his designs as Open Source, but I don’t think I’d be interested in purchasing them from a for-profit organization if he wasn’t compensated.
    That said, thanks for all you do. Love your stuff.

    1. We are going to be donating a small part of the profit to charity. This was not required by Tom, just that we have our own branding. Furthermore, Tom has insisted upon no financial compensation.

      We will also offer 100% of the customer support and assembly instructions for any Sound Study products.

      Tom’s article explains his intentions in offering open source hardware and software.

      Synthrotek intends to continue to bring open source to the market in order to provide the DIY community with greater access to many fine products. Look for more ‘Sound Study’ series products soon!

  2. what a legend guy i had not heard of this till now ,i agree the man should be given something ,
    he is pushing innovation forward so to make a profit without giving him something is pretty slimey !

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