Buchla 285e Frequency Shifter / Balanced Modulator

The top section of the dual-function 285e performs frequency
shifting; up and down outputs are simultaneously available. The
reference frequency can be externally applied or internally generated;
the latter can be voltage-controlled and modulated using FM.

The bottom section is independent, and functions as a balanced
modulator of the applied signals. The degree of modulation is
voltage-controlled, and the reference frequency can be internally
generated or externally applied, as with the frequency shifter. A
separate audio output is dedicated to classic ring modulation, a subset
of balanced modulation.

All settings of the 285e can be stored and recalled as part of a preset using the 225e or the 206e Preset Manager.