And Moxie Scores!

[Johan Gustavsson]

No, that subject line has nothing to do with the recent AH "Hang around
in bars" thread...Rather, I've scored a VZ-1 for around $25 from the
local music chain store! *much rejoicing* Only problem is, it's
completely fried, some of the circuit boards are missing and it's
got smatterings of weird black grime all over itself *crowd goes
"AAAaawwww"* Only it doesn't matter, 'cuz I'm goint to build a CV
keyboard out of it anyway! *wild cheering* I went into the store
asking whether they had any broken keyboards to spare, and they said
"Oh, yes, we've got this victim of a roof leak. You can have it for,
oh, 25 bucks perhaps?". They probably thought I was quite mad :-)

So to start off my "build a Maxx" project, I've gotten myself a five
octave, full sized keys keyboard (useful) with very accessible key
contacts and stuff (good), three wheels (pitch, mod and sprung mod)
and two sliders just waiting to be brought into action as CV or LFO
sources (nice) and a bunch of buttons that I'll find out something
good to do with. On top, the PS part of the keyboard was in prime
condition, consisting of IEC three-prong socket, fuse, and a
voltage-adjustable transformer that gives me +-16v and +8v - Just the
thing for nicely regulating down to +-12, +5...Now, that's nice :-)

Now, looking at Toms keyboard circuits, there's one for one switch per
key and one for two switches per key, the last one being the preferred
one. Now, this keyboard ends up at something like 1 1/2 switches per
key, in that it does indeed have two switches, but they are obviously
triggered by shorting to ground or something, since they share a
common bus line. So, where Toms circuit demands something like this:

   --- (resistor chain) 
    |
      /
     /
    |
   --- (CV bus)

   --- (V+)
    |
      /
     /
    |
   --- (gate bus)  ...on every key, I've got something like:




   ---
    |
      /
     /
    |
   ---
      |
      | ---
      |  |
      |    /
      |   /
      \  |
        ---

...on every key. Now, the question is of course: Is it possible to
build something to utilise the two switches, even though they have one
connection in common? My limited electronics knowledge and I have been
poring over the schematics and haven't found a solution, but then
again we're not very good at this, my brain and I :-) Of course, I
could go with the single-switch solution and just not care about the
second switch, but it seems a slight waste somehow ;-).

Then again, I suppose one could do something with the existing diode
net and a bunch of D/As, but I've got absolutely *no* idea on how to
do that...

Anyway, I'm going to spraypaint the shell of the keyboard some garish
colour (Green, probably) whilst keeping the wheels and sliders
black. Ought to look quite good, methinks. Still, it won't have quite
the portability I'd envisioned (My idea is to build a Maxx inside a
big suitcase, to make a portable modular system), but then again, it's
still time to find a small keyboard to convert, too.

And today I've also found a good room to put up my studio in, and I've
finished the work on a MIDI thru box cum MIDI switch that someone is
buying from me...Today, life is OK :-)
/Moxie (Happy)