Boards I bought from EPE (for the EPE June 2008 Theremin) had a fault on the circuit board, under the opto-coupler (VCA) .. This fault shorts the audio signal to ground.
This document shows how this section should be wired.. All that one needs to do to fix the problem is to cut the PCB with a sharp knife, to remove the short.
EPE Layout bug fix .pdf (381.6 K)
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