MOTM

OK, I have some comments on this.

1.  I have a keyboard assembly that is brand new that was manufactured for
a MicroMoog that has the resistor assemblies already installed and ready to
go.  I bought the thing for $25. No, I am not selling it.  However, I can
tell you that the accuracy is not very good.  I have compared my MicroMoog
CV output to the Kenton pro-2000 and the Kenton wins, hands down.

2.  I don't see what the big deal would be to make a CV keyboard with each
note tunable.  I think if I were doing it, I would use BOTH fixed and
variable resistance.  As I see it (and please jump in there if you
disagree) the problem with fixed resistors is exact accuracy.  The problem
with variable resistors is stability and cost.  And, you would not want to
connect variable resistors so that tuning one, changes the total resistance
of the string.

So, I would make my voltage divider with the a fixed resistor and trimmer
in parallel.  Then, this parallel combination would be connected in series
with as many as I needed for the number of keys I was planning (and maybe
trimmers on the ends for range).  I would plan the voltage at the resistor
junctions to be about 1/2 way between the voltages I wanted on the keys so
that the wipers of the trimmers at 50% would be very close.  Then each key
could be individually tuned without effecting the others.  I think I would
make the trimmers multi-turn and of a higher value than the fixed
resistors.

What I haven't thought out yet is how the divider would connect to the keys
so that you could have a switch between lowest note or highest note
priority.  Or how to make sure that two notes pressed at the same time
don't short out part of the divider network.  I'll have to look at some
schematics.

Decent trimmers can be purchased in the ~$2 range.  So, I don't see why it
has to be that expensive.

Stooge Larry (who is probably missing the obvious)


----------
> From: ivancu@...
> To: motm@egroups.com
> Subject: [motm] CV Keyboards
> Date: Tuesday, May 30, 2000 11:10 AM
> 
> I know this is somewhat silly, but is anyone out there still making a 
> control-voltage keyboard?  No, I don't want to use a MIDI keyboard with a

> MIDI-to-CV converter.
> 
> Ivan
> 
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