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 (+3^dB/_oct spectrum)
• white noise (0^dB/_oct spectrum)
• pink noise (-3^dB/_oct spectrum)
• red noise, a.k.a. brown or brownian (-6^dB/_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 1^V/_oct scale;
• quantized random voltage with n+1 stages tuned in octaves referred to 1^V/_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.