Buchla 112 Touch Controlled Voltage Source

Okay, first off the 112 does not sense preassure - it's contact surface area. Although pressing harder on the touch-pad DOES increase the contact area, the best result is had by transitioning between touching with the finger tip and transitioning to a flat finger (click on image above for a video).

A slightly moist finger helps increase the preassure output (same with Roman's 216r).

Many people Lacquer or varnish their Buchla touch keyboards, as did Buchla/CBS/BEMI over the years. I used polyeurathane on my Roman 216r's, but after playing with the 112 without, I realized it would work better without the coating (and moistening the fingers) so I scraped the varnish off my 216r's (a real pain in the butt, even though it was flaking off in spots). To be honest, I don't think it really matters much if you coat these things or not.