MOTM

On Fri, 17 Aug 2001 mate_stubb@... wrote:

> 2. The single most important useability feature would be to adopt the
> Yamaha convention of having the zero point be where you first put
> your finger down. That way you can touch down anywhere on the ribbon
> and do finger vibrato, or smooth sweeps away from the current control
> voltage. You could have another mode switch that allows it to operate
> the other way as well.

  For those interested, here is how Yamaha did this:

http://www.cs80.com/csribbon.gif

  They just detect when the ribbon is touched and store the initial ribbon
contact voltage on an S/H cap.  Part of this circuit shows the coarse/fine
tuning knobs used on a CS.  The output drives the top end of the DAC
'octave' resistor ladder in the CS.  Modular use would just need the
output scaled for +/-5V or whatever.  I am unsure what the ribbon
resistance is, but that should not be too critical.  I'll measure it the
next time I have the CS-80 open.

  Oh, the 'down' and 'up' gates can be picked off those comparators and
buffered for gate/trig use.

Crow

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