Grant Richter grichter at
Mon Nov 15 20:43:50 CET 1999

E-mail honcho at and ask John Simonton
directly. John is a very nice man and he will help you
figure it out (if he can).

> From: Mark Smart <smart at>
> To: synth-diy at
> Subject: PAIA MCVI card
> Date: Monday, November 15, 1999 11:43 AM
> Hi.
> I recently got out my old PAIA MCVI and Mux Master cards (this is the
> MIDI to CV converter card set PAIA had before they came out with the
> MIDI2CV8 they have now) and installed it into my ARP Axxe. I am having
> problems with it and could use advice from someone who has built these
> cards before. The cards were dying pretty regularly until I got rid of
> cheesy on-board regulators to turn +15V into %v for the logic supply.
> I hooked things up to a real 5V power supply, it stopped dying. The
> I'm having now is that the 6522 VIA chip on the Mux Master board dies and
> makes the Trigger output stay high all the time. Resetting the boards
> it work ok for a while, then it dies again. When I first hooked the card
> to the Axxe, I didn't put any interface circuitry between the TTL trigger
> outputs on the card and the Gate input on the Axxe, which expects 15
> I'm thinking I might have toasted the 6522 in the process of doing this,
> I ordered replacements from PAIA. I also assembled these boards a long
> ago before I knew about water-soluble-flux solder, so maybe the flux
> residue on the boards is messing things up. My next thing to try is
> the flux off with isopropyl alcohol. 
> Other than this problem, the boards work great now. I have been using it
> play the Axxe from my Yamaha WX-7 wind controller. I added patch point to
> the Axxe so you can use your breath to control the VCF cutoff and VCA
> What an expressive instrument!! I'm amazed at what realistic wind
> instrument sounds you can get out of this very primitive one-oscillator
> synth just by controlling it with a wind controller. WOW. 
> Anyway, if anyone has built an MCVI setup and has had similar problems, I
> would appreciate their advice. Thanks!
> ************************************************
> *     Mark Smart                               *
> *     Electronics Engineer                     *
> *     And Musician                             *
> *     smart at                      *
> ************************************************

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