Today, our find is another obscurity from the wide world of synthesis: a very rare Bode Frequency Shifter Model 735. This rackmount device was developed before the Moog Model 1630, which Harald Bode licensed to Moog.
Harald Bode was a pioneer in the early days of synthesis. Although he is less well-known than Robert Moog or Don Buchla, many of his designs were direct influences on both of those household-name engineers.
The Bode Frequency Shifter can process any audio signal with a type of part-ring mod, part-pitch-shifter sound effect, which results in odd and dissonant tones. The circuity in this model is still highly sought-after today and can be seen in various Eurorack clones. It's often reimagined in modern software as well.
According to seller Knobs Electronics, this unit was restored some years ago but is still fully operable. Be sure to check out the listing to make an offer on this unique piece of synth history.