MATRIXSYNTH: Plan B Model 15 Rev.2 with 15A Expander

Thursday, May 03, 2007

Plan B Model 15 Rev.2 with 15A Expander

"The Plan B Model 15 Rev.2 will begin shipping on May 6, 2007. The circuit is identical to previous releases with the addition of a new connector to support the 15A Expander. This is the only circuit change. To facilitate this the PCB had to be redesigned and while we were at it we reconfigured that assembly to mount parallel to the faceplate, taking the overall depth of the module from 4.25 inches to just over 1 inch thick (see photo).

The new 15A Expander adds functionality to the M15 and is a direct result of customer requests. It connects to the Rev.2 VCO via a dedicated I/O connector located on the back of the PCB. It can however be retrofitted to any Model 15's regardless of revision, although earlier releases (rev 1 - 1.6) will require point-to point connections. the 15A is only 4 HP wide and adds a PWN attenuation pot, a Soft/Hard Sync crossfade pot (which amplifies the M15 sync function up to x4 it's previous intensity), 3 three way transposition switch (configured octave up/none/octave down) and two additional 1V/oct VC inputs. The 15A will begin shipping at the end of May with a retail price of $70."

Plan b


  1. Ha, all synths should have a PWN attenuation pot.

  2. "it can however be retrofitted to any Model 15's regardless of revision"

    What would the retrofit entail? Is there any soldering/desoldering needed to retrofit it?

  3. What would the retrofit entail? Is there any soldering/desoldering needed to retrofit it?

    Cutting a couple of parts out, soldering about six wires between the two modules. It's not bad. But they can be sent back to the dealers if nessesary and they can handle it (we do it).

  4. It's interesting to see that Plan B have adopted Wowa Cwejman's unique approach of mounting the PCB and components parallel to the front panel. Well, for this module at least.

  5. Similarities to Cwejman were coincidental (I think Wowa's are among the most elegant execution sof that concept out there). This to me seems more likened to Livewire's scheme - but the reasons we did it were purely practical. Parallel mounting is not something we're going to across the board unless it makes sense and in this case, it did.

    The VCO before was at the Deopfer-allowed maximum height and depth. We had to add a connector, and there was no room to do that. The reason for this was it the board was originally laid out as single sided - meaning traces on one line of the PCB only. Over the coming months we went with double sided fab, and were adding traces on both sides of the assembly, originally for cost reduction to remove all the jumpers required before. But still there were some traces that were wrapping all over the place due to it once being single sided. There were also considerations for packaging - it required a big box.

    Parallel mounting is difficult for us to engineer due to the jacks we use. Clfif jacks mount from the side, not the bottom.

    - P

  6. Thanks for the explanation, Peter. Very keen on Plan B and hoping to get some modules soon.

  7. Yeah.,..I typed "PWN" instead of "PWM" ....let's all get the cuckle over with so we can go on...




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