Buchla/Serge Keyboards

[J.D. McEachin]

At 10:35 PM 5/24/96 -0500, J P M wrote:
>Has any one built or tried to build touch plate keyboards like the ones 
>on the Buchla/ Serge Mods.If so what contact/conductive material did you 
>use for them,and does anyone have any (detailed) plans.I have a few 
>books , and electronotes that that contain theory , but no die hard 
>plans...

Sometimes listmember Ian Stokes built one, I believe from Buchla schematics.
I got a chance to play with it a little.  It's made of etched copper, and
seems to sample & hold the Voltage generated by placing your finger on it.
I'm not sure if it works on capacitive or resistive principals, but I'd
guess it's skin resistance, as your fingers need to be a little moist to use
it.  I doubt it would work for me, as I have the world's dryest skin (comes
in handy when playing with line Voltage).  I would think oxidation would
eventually be a problem w/ copper.  If memory serves me correctly, the Serge
TKB is built with aluminum (but it seems that oxidation would be a problem
with aluminum as well).  I believe schematics of it are also floating around.

JDM
Synthcom Systems, Inc.
http://www.synthcom.com/