Bastl Grandpa & Spa Repanel mxmxmx One is the vactrol which

One is the vactrol which is a light controlled resistor

and by the contact microphone and phonograph cartridge experiments of John Cage

special circuit elements between the four integrators provide the nonlinearities required to produce chaotic oscillations

entitled "Book"

the resonance control makes the circuit self oscillate

Bastl Grandpa & Spa Repanel mxmxmx One is the vactrol whichThis is the first release in our Bastl Repanel series which attempts to be true to the original aesthetic There are a few things to note with this panel 1) The red acrylic window does not fit into our repanel I sanded the top of mine down to fit. We will be address this in later revisions, but I kind of like it better without the window anyways. 2) The spa expander will not be sold separately. 3) Because of the thickness of the original wood panel