References
Distortion Quick Reference
Distortion 
MOD 
BIAS 
Description 

Disto 
• 
• 
It has a nice analog feel. The brightness of the distortion is controllable. 
SftClp 
• 
• 
Waveshaper, symmetrical and soft. MOD will make it asymmetric. 
HardClp 
• 
• 
Waveshaper, symmetrical and harder. MOD will make it asymmetric. 
StrgrC 
• 
• 
Waveshaper, symmetrical and stronger. MOD will make it asymmetric. 
Crest 
• 
• 
Waveshaper, symmetrical, and not bijective. MOD will make it asymmetric. 
Fezz 
• 
• 
Waveshaper asymmetrical. 
Fuss 
• 
• 
Waveshaper asymmetrical. 
Attrac 
• 
• 
Multiple states distortion. 
SmartE 
• 
• 
Varying waveshape. Use MOD to change the waveshape. 
Sstrgi 
• 
• 
Waveshaper with ripples. 
WavFld 
• 
• 
Wavefolding Cyclic waveshaper. High gain will produce ”tuned” noise. 
NoizE 
• 
Cyclic distortion. High gain will produce white noise. 

Antipol 
• 
• 
Crest mangler. MOD to 50% will be similar to a HardClp. More than 50% will reverse the crest. 
Anti+ 
• 
• 
Same as antipole, with an additional waveshaper on the crests. 
Cross 
• 
• 
Waveshaper that affects the low portion of the signal. 
Cubic 
• 
Waveshaper. Will ‘dry’ the signal. 

Vshpe 
• 
• 
Will tend to produce a higher pitched sound. 
Square 
• 
Waveshaped rectifier. Will tend to dry the signal much more than Vshpe. 

Lowfi 
• 
Slew rate limiter. This is an extreme version of a physical limitation that exists on any amplifier. MOD will change the slew rate limit, raising it will give more highs. 

Lowrfi 
• 
• 
Waveshaped slew rate distortion. 
BrwnNz 
• 
Random walk on a waveshaper. MOD at 0 will create noise. 

Filter 
• 
• 
Waveshaper followed by a resonator low pass filter. The higher the distortion gain, the higher the resonance. MOD will change the cutoff frequency. 
DwnSpl 
• 
• 
Emulates an analogue sample & hold. MOD will change the hold time. 
Bitcrsh 
• 
• 
Crushes the bit resolution of the signal. May oscillate when used in the Xxx mode. 
Jelly 
• 
• 
Envelope follower driven Distortion. 
Fractl 
• 
• 
Uses a chaotic feedback equation to distort the sound. A bit experimental, pretty weird and analogue sounding. MOD will change the recursive depth. Use some BIAS to make it unstable. 
Accum 
• 
A distortion that can add low frequencies! It behaves a bit like a modulator, but it’s not. Experimental, nice on drums particularly. 

TimeFr 
• 
• 
Freezes portions of the audio signal depending on the BIAS, MOD and GAIN. 
Clicks 
• 
• 
Adds Vinyl clicks, with a click density depending on the MOD parameter. 
ChastB 
• 
• 
A floating point mantissa distortion. 
SuspB 
• 
A floating point exponent distortion. 

VariWS 
• 
• 
Variable asymmetrical waveshaper. 
Vinyl 
Features RIAA filters, used in vinyl signal encoding/decoding, and an emulation of stylus degradation. 

Vynil 
• 
Based on the same principles as Vinyl. 

Bounce 
• 
• 
Emulate the behavior of a ball in a cylinder where the top and bottom move accordingly to the sound. The MOD varies the ball inertia. 
Zippy 
• 
• 
Distortion using a chaotic oscillator. The MOD varies the oscillator frequency. 
Valve 
• 
• 
Asymmetrical soft distortion. Produces even order harmonics which reduce when MOD rises, resulting in a brighter sound. 
Distortion Reference
FAM
When FAM is on S or X, after the band processing stage (XOVER and LPF IN), and except where otherwise noted, the signal is offset by BIAS and then GAIN (pregain) is applied before the signal enters the distortion. The DC offset introduced by the BIAS offset is then compensated.
When FAM is on O, BIAS is used instead to expand or shrink the relation between harmonics generated by the distortion.
There is one exception though for Fractl, when FAM is on O: BIAS will control the DC offset (instead of the relation between harmonics), and MOD is used instead to control the relation between harmonics generated by the distortion.
Disto
Disto is a limiter where the MOD parameter controls the attack and release time, giving an analog feeling. Increasing MOD will reduce the attack and release time from a few milliseconds to a few hundreds of microseconds.
SftClp
SftClp is a soft logshaped waveshaper symmetric curve. Increasing the MOD parameter control will make it asymmetric, bringing even harmonic and a warmer, richer sound.
Even though the asymmetry of the waveshaper when using MOD implicitly creates a DC offset, the DC offset is compensated later in the algorithm. This is also the case for all the following waveshapers.
The diagram below shows SftClp shapes. The plain line is for MOD turned fully left, and the shaded lines are examples as MOD is turned right.
Crest
Crest is a nonbijective waveshaper symmetric curve behaving a bit like a wavefolder around the clipping region. Increasing the MOD parameter control will make it asymmetric, bringing even harmonic and a warmer, richer sound.
Fezz
Fezz is a waveshaper but with an asymmetric curve. Increasing the MOD parameter control will push further the asymmetry for a richer sound.
Fuss
Same as Fuss, but with a different asymmetric curve, with a “folding” similar to Crest in the positive values of the input signal.
Attrac
Attrac is a multiple states distortion: at low GAIN settings, the current signal voltage is “attracted” to either 5V or 5V, like an electron steered by the two deflection plates of a cathoderay tube. As the GAIN parameter is raised, the attractor enters a more chaotic behavior.
The MOD parameter controls the attack and release time of an envelope follower of the input signal, which in turn restrain the chaotic response.
Note
As a consequence, if the input signal doesn’t have fast enough variations of volume (such as a plain VCO output), MOD will have no effect.
SmartE
SmartE is a waveshaper with a varying shape. The MOD parameter controls the shape of the waveshaper.
Sstrgi
Sstrgi is a nonbijective waveshaper symmetric curve with multiple wave folds. Increasing the MOD parameter control will make it asymmetric, bringing even harmonic and a warmer, richer sound.
WavFld
WavFld is a textbook implementation of a puncher (sinusbased) wavefolder. Increasing the MOD parameter control will give a new take of this classic.
NoizE
NoizE is an implementation of a cyclic triangular wavefolder. Increasing the GAIN parameter control will make the output signal more and more noisy. The MOD parameter is inactive.
Antipol
Antipol is an implementation of a hard clipper. Increasing the GAIN and MOD parameters controls can make the output signal fold on itself.
Anti+
Same as Antipol, but the output signal will fold quicker when hard clipping and increasing the MOD parameter control.
Cross
Cross is a soft nonbijective waveshaper symmetric curve behaving a bit like a wavefolder around the clipping region. Increasing the MOD parameter control will make it asymmetric, bringing even harmonic and a warmer, richer sound.
Cubic
Cubic is a nonstandard symmetric waveshaper curve crushing the low part of the signal. The MOD parameter is inactive.
Vshpe
Vshpe is a nonstandard antisymmetric waveshaper curve with a Vshape. Increasing the MOD parameter control will make it asymmetric, bringing even harmonic and a warmer, richer sound.
Lowfi
Lowfi simulates an operational amplifier integrated circuit with a nonHiFi slew rate, bringing a LoFi type of sound. The lowest MOD is, the lowest the slew rate, and the more LoFi it sounds.
Lowrfi
Same as Lowfi, but the operational amplifier integrated circuit also shows strong nonlinear properties.
BrwnNz
BrwnNz is a Brownian noise or “Random Walk” applied on the input signal. The MOD parameter controls the sampling rate of the input signal. The lowest it is, the most it appears as a pure brown noise.
Filter
Filter is a waveshaper followed by a lowpass resonant filter. Increasing the GAIN parameter control will make the resonance higher, and the MOD parameter controls the lowpass cutoff frequency.
DwnSpl
DwnSpl emulates an analog sample & hold filter with an integrated polynomial bandlimited step function combined with a waveshaper. The MOD parameter controls the sampling frequency rate. This distortions allows to replicate the effect of vintage digital synthesizers with low sampling rates.
Bitcrsh
Bitcrsh is a typical bitcrusher. Increasing the MOD parameter control makes the effect more intense, and so lower the number of bits used to represent the input signal.
When MOD is high (a few bits), and GAIN is low, the input signal can be lower than the level of the least significant bit, and the output will be silent.
Conversely (for the same MOD) when BIAS is far from its center position, the input signal will clip, so that the signal might sit between two consecutive bits, and the output will be silent.
Jelly
Jelly is a distortion that can’t be described with human words. The algorithm is also a total nonsense and yet, here it is.
Fractl
Fractl is a fractalbased distortion model. Increasing the MOD parameter control sets the number of passes of its recursive algorithm.
Note
However when FAM type is O, BIAS will control the DC offset (instead of the harmonics tuning) and MOD will control the harmonics tuning (instead of the number of passes of the algorithm).
Accum
Accum is an experimental distortion that acts like a modulator somehow, but not really.
TimeFr
TimeFr is a delay line that “timefreezes” the input signal, based on an envelope follower. The MOD parameter controls the analysis time of that envelope follower.
Clicks
Clicks adds Vinyl clicks. Increasing the MOD parameter control will increase the click density.
ChastB
ChastB is an experimental bitfiddling floating point mantissa digital distortion.
SuspB
SuspB is a experimental bitfiddling floating point exponent digital distortion.
VariWS
VariWS is an asymmetrical waveshaper with a varying shape. The MOD parameter controls the shape of the waveshaper.
Vinyl
Vinyl uses the preemphasis and complement deemphasis RIAA equalization curves with soft asymmetrical waveshapers to model nonlinearities of the stylus. The MOD parameter emulates the stylus degradation over time.
Vynil
Vynil is a variation of Vinyl with a different topology for handling the DC offset implicitly generated by the RIAA equalization curves.
Bounce
Bounce emulates the behavior of a ball in a cylinder where the top and bottom move accordingly to the signal input. The MOD parameter controls the gravity of the system and the air friction to limit the ball speed for stability.
Zippy
Zippy is an original distortion based on Lorenz attractors with a 1dimensional projection. Increasing the MOD parameter control will make the output signal more chaotic, and so more bright.
Valve
Valve is a soft hyperbolictangentshaped waveshaper symmetric curve. Increasing the MOD parameter control will make it asymmetric, bringing even harmonic and a warmer, richer sound.