Eisen Audio was hired to design and build a rackmount submixer, which is patched into the tape loop of a vintage (and primitive) Bozak DJ mixer, providing effects integration and monitoring capabilities as part of the Despacio Sound System.

Discrete transistor circuitry was employed exclusively, with extensive “tuning” by-ear, in order to blend in with the construction and tonality of the aforementioned vintage Bozak mixer. All of the signal routing and switching is done using photo resistors so that it’s always safe to make daring on-the-fly mix moves without fear of “pops”, “clicks”, or “bad edits”. All of the rotary faders are high quality conductive plastic, selected over a dozen competing offerings for minimum noise.

Two different mixer prototypes have been constructed thus far, based on end-user requests and feedback, and are touring the world. We hope at some point to revisit this project – down time and budget permitting – in order to develop a special-order product from it that could be useful to many other DJs who are committed to the vintage rotary mixers.