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:-

E-F-F#-G-G#-A-A#-B-C-C#-D-D#-E
(Normal chromatic scale)

If the [1/6 SELECT] scale is enabled, then the scale produced will be:-

E-F#-G#-A#-C-D-E
(whole tone scale)

If the [1/3 SELECT] scale is enabled, then the scale produced will be

E-G#-C-E
(scale of major third steps (augmented triad))

If both the [1/6 SELECT] and [1/3 SELECT] scales are enabled, then the scale produced will be:-

E-F-G#-A-C-C#-E
(Six-step major-minor (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 effects, 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.

Build Guide