Various pictures of musical equipment
The YC-30 is just unique. Sun Ra used it, among many others.
Here's the owners manual.
A nice device but the manual is quite rare. Here is a copy:
Part of the Gratis Pack
Bertha 2 is a polyphonic additive synthesizer with a few extras. With its eight tone generators, and drawbar-style control, Bertha 2 excels at producing sounds reminiscent of vintage Farfisa or Vox transistor organs. The requisite vibrato, chorus and distortion effects, along with the Leslie speaker simulation, let you conjure up all manner of classic organ tones for the garage, the arena, and the church. Going beyond the earthly realm is simply a matter of engaging Bertha 2’s microtonal mode and taking advantage of the device’s full-featured ADSR envelope – fascinating, otherworldly textures await.
Available at Ableton