DSI Mopho x8 project

My DSI Mopho x4 (SSN #10) has become my main secondary board on the fly, as it’s small enough to fit in an overhead, and easy to throw in the car when I’m not sure a 2nd board is required (but always like one!).  I just brought it through 2 airports, EU customs, and to the shores of Monaco and back without a hitch.  It’s also flown to China this April, and Australia at New Years, as backlining a Dave Smith is not always possible or practical.  (although Motifs seem to be in no short supply……)  Tour managers like it when you cut down on costs. :)  The only drawback of this gem is it’s 4 voice limit, which is just under the 5 (Prophet 5) or 6 (Juno-60) voices that would make it the perfect polyphonic analog synth IMO.  SO after getting some preliminary blessings from DSI, my solder-worthy friend Luke Fackler and I set out to make a Mopho x8, hiding a stripped down Tetra inside.

We have finished a preliminary build, with the Tetra bolted down inside, midi internally hardwired to the x4’s Poly-chain out, and daisy chained power, but haven’t solved an audio summing issue.  Passive summing attempts so far have caused imbalances between the two synths, so we’re exploring some active options.  The two usually have to be mixed externally to poly-chain, but the whole purpose of the project is to make a quick and easy Mopho x8, with zero extra setup.  Until we solve the stereo summing issue, Luke made a mono out jack for the tetra.  Eventually we plan to have it all summed to the Mopho x4’s original stereo outs, as well as the headphone jack, making for a fantastic road synth.

I’ll be taking it on the road with me next week as I embark with Quadron around the US and Europe.  I’m running the Mopho through an analog chorus pedal with a mono in/stereo out anyways, so the lack of stereo at the moment doesn’t bother me.   I’ve only sacrificing the internal Mopho panning, but a Strymon Mobius is in the mail, for stunning stereo in/out mod fxs.  Until the next break!

UPDATE:  After 2 weeks with Quadron, 6 raised TSA eyebrows, 6 overhead compartments, and 8 shows, the x8 is still running quite smoothly!

But I’m already quite happy with where it’s at.  I don’t have to carry around a midi cable, an extra PSU, and a Tetra anymore.  Abe Gearig, another friend, and a skilled drummer, assisted with the process.  I mostly watched, as I’m useless with a soldering iron.  Thanks guys!  *There were several surprise complications as usual, so don’t assume you can just strip a Tetra and plop it inside, lest you be inspired to follow suit.  Feel free to send questions on the build.  It’s a continuing saga, and hopefully someday it will be completely finished.

Lucas Fackler is an audio engineer, guitarist and vocalist for his band The Will, video editor, and fierce friend.  I encourage you to explore his work and art at www.lucasfackler.com

Abe Gearig is a drummer for The Will, Lido Beach, and also a fierce friend.  Check them out at http://www.reverbnation.com/artist_94641/bio

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One Response to DSI Mopho x8 project

  1. Marcelo says:

    Hi Peter,

    So in the end could you sort the audio summing issue?

    I was thinking about making the same mod.


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