Besides its quantizers, which are part of the random sections, Sapél is a completely analog module. The noise generator features four outputs, each of them emits a different kind of signal:
- Blue noise (Spectrum: +3 dB per octave)
- White noise (Spectrum: 0 dB per octave)
- Pink noise (Spectrum: -3 dB per octave)
- Red respectively brown noise (Spectrum: -6 dB per octave)
The random sections are composed of four channels each. One signal path produces fluctuating random voltages in the range of 0 V to +7.5 V. For influencing the channel's work, there is a frequency potentiometer plus a CV input.
Two other channels generate quantized random voltages with semitone and octave intervals. The number of stages used by the circuit (n) can be varied in the range of 1 to 6 via potentiometers and CV inputs. The signal paths use the given values as follows:
- 2n channel: Produces control voltages that are quantized to 1/12 V steps. (Results equate to semitones in the 1 V per octave scale.) The value range goes from 2 to 64 stages. (0 V to +5.25 V)
- N+1 channel: Produces control voltages that are quantized to 1 V steps. (Results equate to octaves in the 1 V per octave scale.) The value range goes from 2 to 7 stages. (0 V to +6 V)
The fourth signal path of each random section emits non-quantized sample and hold material in the range of 0 V to +7.5 V.
The Sapél’s clock source is composed of two pulse generators. Signals produced by the fluctuating random channels form the basis for their work. The clock frequencies can be set via potentiometers. Additionally, there are CV inputs for modulations. 2n, N+1 and S&H channels work in sync with the associated pulse generator. Furthermore, there are two connectors for normal and random clock signals. The chance output offers two modes of operation:
- More than mode: The connector emits random triggers plus the normal clock signal.
- Less than mode: The connector emits random triggers only.
Via switches, it is possible to combine both clock generators. This feature allows users to create very complex results with 2n, N+1 and S&H channels. Furthermore, the circuits can be manually triggered via buttons and gate signals. Alternatively to the built-in clock source(s), external sync signals can be fed to the module.
Thanks to its probability section, users are able to influence the amplitude of random voltages generated by the Sapél. In detail, it is possible to lower the probability that medium and high values are generated. Switches determine which channels of the random sections get affected by these settings.
Per random section:
Four CV inputs
Four signal outputs
Per clock generator:
Combined CV frequency and gate trigger input
(A switch decides, which mode of operation is active.)
Normal and random output
Outputs for white, blue, pink and red noise
3U Eurorack module, 18 HP wide, 38 mm in depth
Power consumption: 250 mA at +12 V and 170 mA at -12 V