The SAPÈL is a random control voltages source for eurorack modular systems.

It is composed of two main sections, one that generates audio noises, in 4 different versions, and another which includes two specular random clock, random voltages and clock sources. Noise outputs are color coded, based on the noise colors, and include: blue (+3dB/oct spectrum) white noise (0dB/oct spectrum) pink noise (-3dB/oct spectrum) red noise, a.k.a. brown or brownian (-6dB/oct spectrum).

The random voltage and clock section features four uncorrelated random CV generation paths, divided in

• fluctuating random voltage
• quantized random voltage with 2n stages tuned in semitones referred to 1V/oct scale
• quantized random voltage with n+1 stages tuned in octaves referred to 1V/oct scale
• non quantized sample & hold. It is also possible to set a probability distribution with a potentiometer, and apply (or do not apply) the chosen distribution setting to each of the four paths independently.

Furthermore, each of the two random sources section features an independent built-in clock generator, with clock output and random clock output, which can be used in “more than” or “less than” mode. It is possible to use an external clock signal as a clock source, bypassing the built-in one. In addition to that, it is also possible to hand trigger the clock via a manual sample & hold button, which can be also modulated by gate signals.