MATRIXSYNTH: Inside a DSI Tetra


Tuesday, August 18, 2009

Inside a DSI Tetra

via Nova Musik

Note the "Phour!" in the top right.

TETR4
TETRA

Update: image minus logo added

7 comments:

  1. Hmmm looks like ROMS are making the SSM clone. The chip marked DSI-120. (I wounder if it really is a clone)

    ROMS made all the custom synth chips for Roland back in the day. Would love to see a data sheet on the DSI-120 chip. (won't happen, but I can dream)

    ReplyDelete
  2. Quiet a crowded board. In the upper right you can see "Phour!" ... I guess that was the original name.

    ReplyDelete
  3. that a ROHS stamp (the EU mandated restriction of hazordous substances stamp, generally indicating lead free etc..).
    The chips are custom made for DSI.
    ROHM is the other manufacturer you're thinkning of.
    I think Alan is right, name was probably phour. Tetra sounds better I guess.

    ReplyDelete
  4. So, I can barely read them but it looks like there's two Microchip dsPIC parts on the board. I wonder if they are being used as DCOs? Supposedly the signal path is entirely analog though.

    ReplyDelete
  5. I guess its CEM not SSM ? Anyway these chips dont "drift" whether VCO or DCO construction, I take it as a good thing. The Pro 08 got some fire for the sloppy pots but certainly not for its phat sound. Same standard should apply here soundwise.

    ReplyDelete
  6. dsPICs might be used to generate a digital timebase for DCOs. The one on the left looks like it's a dsPIC33FJ128MC506, so I'm guessing the one on the right will be one more of the same.

    Also, it looks as though there's another circuit board underneath that one (look at the top right corner, where you can see the legs of a chip soldered to the board, but no chip). I'm guessing that's where the control / UI circuitry will be sat.

    ReplyDelete
  7. Actually, not just the timebases; I'd hazard a guess that they generate all the control voltages too, and also present a nice interface to the voice control stuff (I'd use CAN, myself).

    ReplyDelete

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