Paia MIDI2CV mods

[Bob Zimmer]

At 07:10 PM 7/11/97 -0500, you wrote:
>I built two of the PAiA MIDI2CV kits (one V/Hz and one V/Oct) and put them
>in the single space rack kit.  It is a nice way to house two of these units
>for rack mount and use with various synths instead of dedicated to one
>machine.  I have made a copuple of simple mods to mine and am about to make
>another major one.  I was wondering if anyone else had moded theirs and
>how.

My works quite well, but I'm only using it in the single voice mode to get
access to all of the control voltages associated with it.  I've heard
problems (should be in the DIY archive) with the multi-voice modes!

>My first mods were simple.  1 - power jack instead of the
>"cord-through-the-grommet" connection.  2. grommets in the 1/4 holes in the
>back and cables out to 1/4 jacks on a separate single space panel below. (
>I used terminal strip in the vacant space between the boards so I could
>hook up both the 1/4 jacks and still retain the 1/8 front panel jacks.) 
>
>BTW, I fould a decet source for 1/4 stereo jacks that seem to hold up and
>make good contact.  And all three contacts (T-R-S) have a switch on them. 
>Looked like they were designed for a patchbay. PC mount (however, soldering
>wires directly works fine too)  20 cent each by the hundred at all
>electronics.  PLastic housing requires no isolation from panel ( if needed)

For quality 1/4" jacks, I personally would only consider Switchcraft!  I
have some of theirs that I installed 20+ years ago and they still function
perfectly after thousands of inserts over the years!  Yes, they do cost
more, but I think you get what you pay for on them.

>The mod I have just ordered the parts for is a tuning mod.  I got some 20
>turn 1K pots from mouser and plan to sacrifice one of the 1/8 jack
>patchbays (8) to have 6 tuning pots available at the front. (1 for each DAC
>and 4 for the octaves on the V/Hz board.  Then when tuning varies from
>different synths I use it with, tuning will be easy and acurate.

I'm doing a similar thing by putting in the CV Range & Scale circuit from
Electronotes and adding Gene Stopp's Portamento circuit (switchable
linear/exponential).  The portamento works great and there is quite a
difference between the two modes.  The CV Range circuit works flawlessly,
but I'm still having some problems with the scale circuit.  Seems to only
operate over the first octave of the keyboard!!!  The PC board mounts in
the space reserved for the V/Hz daughterboard.  When I get the Scale
circuit working, I'll put the PC Layout on my homepage.

Bob


  >=== Bob Zimmer -- Phila, PA     bzimmer at voicenet.com ===<
  >===         http://www.voicenet.com/~bzimmer/        ===<
  >=== "Oat-bran noise is more likely to be an issue in ===<
  >=== situations where cereal data ia concerned [:-)]" ===<
  >===         Analog Dialogue - Analog Devices         ===<