While the Moog Etherwave Pro® is commonly known among thereminists as one of the best actual theremins, many players complain its non-optimal volume response which is often described as "snappy". That means that even delicate hand movements above the volume loop don't allow to play continuous crescendi/decrescendi from/to zero volume but silence is followed by a jump in volume from zero to a starting level of about -40dB. The consequences are not only a reduced dynamic range but also the impracticality of sophisticated expression at very low volume.
Based on a modification Dr. Robert Moog himself designed to solve this problem, Thierry Frenkel designed the EPVM1345 module.
The EPVM1345 module comprises 4 different circuits, each giving another volume response characteristic:
- The original circuit, snappy, giving a limited dynamic range of ~40dB
- The modified circuit developed by Dr. R. Moog, less snappy, giving a dynamic range of ~54dB
- A circuit developed by Thierry Frenkel, no perceptible snappiness, giving a dynamic range of ~61dB. The subjective impression which I had when testing the prototype was a volume response similar to that of my very well tuned and adjusted Etherwave Standard®.
- Another circuit developed by Thierry, with a still smoother response, giving a dynamic range of ~67dB. It allows a very sophisticated expression at extremely low volume but exceeds important left hand movement when using the whole dynamic range.