via this auction
"Michel Waisvisz designed and built the very first Crackle circuit in the late 60ties together with Geert Hamelberg. This was simply a wooden frame with some print boards mounted rear-side up to be touched by the fingers. The circuits were ‘malformed’ oscillators that were very unstable and highly sensitive for finger connections. The Crackle circuit, as well as the powered speaker box, were battery powered to avoid hum and repeated exposure to dangerous electrical shocks. In 1973 Michel Waisvisz joined STEIM and started working on more touchable electronic instruments together with Peter Beyls, Nico Bes and Johan den Biggelaar, and by the mid-seventies they had created both the ‘Crackle Synth’ and the ‘Crackle Box’.
The Magnetic Fields recently used one in their album Love at the Bottom of the Sea. Swedish percussionist Sven-Åke Johansson carries one often and uses it frequently in recordings and improvisation. Mazen Kerbaj tours with one of the original Crackle synthesizers.
I used this once and it's been in the box since 2012. I have the pin that keeps the box closed in a baggie in the box. Get it, it's a cool little device."
