Wurlitzer 920 tone cabinet

The 920 tone cabinet was a tremolo unit designed as a companion to the Wurlitzer 112, 112A and 120 electronic pianos. The back of the cabinet could be used as a piano bench. The bench legs and pedal could be stored inside the cabinet.

Unlike organ tone cabinets, the 920 did not have a rotating speaker. Instead, it was a combo amplifier with tube tremolo and tone controls. The tremolo controls were mounted in a separate box that was intended to be attached to the left side of the piano, near the cheek block. The headphone output of the piano then connects to the input of the amplifier via a short cable on the control unit.

In addition to the piano input, the amplifier has unbalanced microphone and instrument inputs. The microphone input enters at the first gain stage, and is amplified by the entire circuit. The instrument input enters at the second gain stage. The piano input (which has already been amplified by the piano’s onboard amplifier, including its push-pull 6V6 output stage) enters the circuit at the third gain stage, so it receives the least amount of amplification.

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