[Re: S&H]

[Harry Bissell]

This might be ok, but the inrush current to the cap will depend on the
resistor matrix on the keyboard. The charging time might depend on which key
you press, and the cap will try to draw INFINITE current when confronted with
a step voltage change. This might fry the gold off the contacts.... Otherwise,
the switch is a good idea. Air is an excellent insulator.  :-) Harry


Mike I <mirwin1 at istar.ca> wrote:
Hello,
Why not disconnect the keyboard CV bus from everything else, connect a 
0.1 - 0.2  microfarad polystyrene cap between ground and the CV bus, and 
buffer the cap voltage with a BIFET op amp voltage follower. The op amp 
output  becomes the keyboard CV output. The keyswitches act as the S/H 
switches now, and leakage is kept at a minimum, plus the CV is 
continuously measured for as long as the key is held down, helping to 
reduce the effects of external noise. Just make sure the cap is not too 
large in order to avoid an unwanted CV "glide" between notes.


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