The electronics chassis. Tube complement is one 6AV6, two 6C4, one 6BA6, and five 12AX7s. The trimpots control the resonance of the bandpass filters that make the drum tones. “SHIMMER GENERATOR” controls the decay time of the noise-based cymbal sounds. The inside of this chassis is quite impressive. Maybe later. (Does anyone out there have the schematic for the Sideman? Just curious. Repairing it is straightforward, but how this thing works is becoming interesting to me.)