[sdiy] Touch switch and theremin chips

[Toby Paddock]

I saw these chips and was wondering if anyone had tried them.
QProx (tm) Charge-Transfer Capacitance Sensors
Quantum Research Group Ltd
http://qprox.com/

Touch switches:
QT60320 - 32 key matrix
QT110 family - single channel
Would this be useful to repair dead switches on synths?

Maybe for a theremin type controller:
QT9701B and QT9701B2 
This is what they told me...
Thank you for your interest in Quantum product. Currently, we 
have one device that would suit your purposes, the QT9701B(2). 
This is a continuous capacitive sensor that can very easily 
sense the presence of a hand from 4 to 8 inches with analog output. 
The cost of the entire circuit in small quantities is about $24.00.

 - -- -  Toby Paddock