The ES37 provides a simple means to turn any control voltages in to voltage steps corresponding to well tuned (equal-tempered) tones of musical scale. It is scaled to 1V/Octave so a 0V to +5V envelope at one of the inputs produces a staircase of voltages corresponding to a chromatic scale.
If patched to the 1V/Octave input of an oscillator tuned to 'E', a slope of 1V applied to the input will produce the following steps of musical scale:-
(Normal chromatic scale)
If the 1/6 Scale Select is enabled, then the scale produced will be:-
(whole tone scale)
If the 1/3 Scale Select is enabled, then the scale produced will be
(scale of major third steps)
If both the 1/6 and 1/3 Scale Selects are enabled, then the scale produced will be:-
(Alternating half-step/minor third step)
Since the Scale Select inputs can be activated very quickly, the ES37 can produce a wide variety of tonal effetcs, quickly moving between four different types of musical scales (chromatic, whole-tone, augmented triad, and a six-step major-minor scale often heard in certain oriental music).
Accuracy of the ES37 is 3-cents maximum deviation from the ideal equal-tempered semitone over a 5-octave range while the response time for all channels is about 8 milliseconds.