[sdiy] Paia MV-8 MIDI CV Processor request for info

[Dave Kendall]

Hi.

I built a MIDI2CV8 a while back, and have been pleased with it. I can
recommend adding a few additional circuits on a bit of perfboard though.

The pitch wheel centres at +5V (+5.33V on my board), with 0V at the bottom
and just over 10V at the top. It's well worth fitting an offset /scaler
circuit on the PB output, so that 0V is the "off" or centre position.
All of the continuous controller outputs are stepped, or "zippery" if left
with 0  to  +10V range. There is a little diagram in the Paia construction
manual showing how to get the pitch bend range down to a more musically
useful range - doing this removes perceivable zipper noise. I wired my PB
output to one sub-circuit giving a fixed ±2 semitones, and to another one
with a pot for range, with a DPDT switch selecting between the two. Both had
the offset set with multiturn trimmers.

To get rid of zipper noise on the other CV outputs (e.g. in mode 1 you have
Mod Wheel and  Aftertouch CVs), use a simple lag circuit on the output of
each, with the rate set so that when controlling, say, VCF cutoff, there is
no audible zippering, but it has an acceptable control response. In
practice, the slight control lag hasn't been a problem.

It might be worth replacing the DAC trimmer with a multi-turn one, although
fitting it to the board might be tricky for space/footprint reasons.

cheers,

Dave




on 9/3/06 22:07, megaohm at megaohm1 at gmail.com wrote:

Hi,

I just picked up a Paia MV-8 and I'm looking for documentation, schematics,
any info, tips , and/or links. Any and all help will be greatly appreciated.


Thanks,
peng

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