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Subject: Re: [motm] DIY keyboard

From: "J. Larry Hendry" <jlarryh@...>
Date: 2000-08-13

Your knowledge on the subject is so far ahead of mine on this Tony, that I
don't even feel like I can ask intelligent questions. My list of desires
and exclusions is nowhere near firm. It is just my initial thoughts. For
example, splits maybe out of the question. As far as velocity information,
I am totally in the dark as to how. Just thinking out loud, it would seem
that some kind of timer between two contacts could be used. When I said
avoid DAC, I guess I was thinking about the pitch CV. Obviously, something
like this would be most certainly be required to converting timing into
voltage for the velocity thing. My ignorance on the subject is certainly
showing, and I am just looking for a starting place from guys well versed in
the subject like yourself. Any, and all input (including telling me I need
to re-examine my wants and exclusions) is MOST welcome.
Larry Hendry

----- Original Message -----
From: Tony Karavidas <tony@...>
To: <>
Sent: Sunday, August 13, 2000 2:29 PM
Subject: RE: [motm] DIY keyboard

Good luck. If you exclude all the things in your list, what were you
thinking would be able to generate velocity information?? How are you
planning on getting a keyboard split with a single chain of precision

There are several ways to accomplish your goals, but your list of exclusions
have made your task much more difficult.


> -----Original Message-----
> From: J. Larry Hendry [mailto:jlarryh@...]
> Sent: Sunday, August 13, 2000 12:06 PM
> To:; synth-diy
> Subject: [motm] DIY keyboard
> Despite the fact that I have more MIDI keyboards than I need and
> a perfectly
> good Kenton pro-2000, I decided to take the DIY plunge and construct a CV
> keyboard for contolling my modular. As luck would have it, I found a very
> nice 5 octave keyboard mechanism built into a very nice walnut
> case that has
> 3 contacts per key. In addition, the precision resistors for the CV are
> already installed. And, in the appropriate place is a great spot for a
> joystick or whatever.
> Now, I have the easy part of this down pat. The pitch CV with the
> resistors.
> I will probably stick in a nice DC op amp with a little summing
> network so I
> have pitch bend with the joystick, and maybe put in an aux CV input for
> other toys. Now, the rest is wide open and I am in the learning
> mode. The
> arrangement of the contacts is such that they do not all have to close at
> the same time. So, looks like a velocity CV is possible too.
> Under the generally accepted principal that "many heads are
> better than one"
> I ask, "what would you include in such a controller?" I am thinking pitch
> CV out, joystick X and Y CV out with the ability to couple one axis of the
> joystick to pitch CV internally, gate AND trigger out, velocity CV, and
> maybe the ability to split the keyboard. And, when using gate only, it
> would be nice to be able to retrigger for the next keystroke (selectable).
> I am planning to avoid DACs, PICs, matrix and all that stuff. I have the
> DAC accuracy in the Kenton. What I want here is monophonic analog.
> So, I would appreciate anyone's opinion of what they would choose
> to include
> in the functionality. And, any pointers toward additional
> reading material
> or schematics that would help me become more familiar with the
> typical type
> of circuity used in CV keyboards would be appreciated too.
> Larry Hendry