Sick Puppy Usage Notes

These notes will help you get the most out of Sick Puppy, the seriously twisted wave-peak analysis distortion generator. DirectX and VST versions are available.

Sick Puppy generates distortion by analysing the incoming waveform, using a variety of techniques to identify the peaks that define each cycle. The output waveform consists of the value of each identified peak, held until the next one is detected.

Originally this analysis was not intended as an effect, rather it was reseach into methods of partitioning an incoming signal to process each wave cycle separately. However, while listening to the output I discovered that it was capable of producing some extreme and unique distortion effects, particularly when filtered before and after the peak-stepper algorithm.

The wave peak analysis works best (the way I originally intented it) on periodic waveforms. That means monophonic pitches - solo lines, basslines. However for destructive sound design there are no rules...

Controls

The Mode switch lets you select four variations of the peak analysis algorithm.
Mode A is a simple sample-and-hold on the peaks and troughs, I originally intended this for signal conditioning.
Mode B adjusts the value of each peak so that it is the difference between it and the previous trough. This "normalisation" was originally intended to make it useful for pitch tracking.
Mode C weights the value of each peak by the area of the surrounding triangle formed by the adjacent troughs.
Mode D weights the value of each peak by the absolute value (ie, how var the value is above or below the zero line).
These are pretty esoteric differences, and if you observe the waveform graphically you might understand what is going on better. The important thing is that they create different distortion effects, particularly if you filter the signal before and after.

The Pre Filter knob controls a simple low-pass filter to remove some of the higher harmonics before the wave peak distortion is performed. Lots of filtering (a low cutoff frequency) can reduce glitching and make the fundamental pitch stand out.

The Drive knob adjusts the gain as the output from the distortion engine can be very unpredictable.

The Post Filter knob controls a low-pass filter after the distortion is generated. The wave peak stepping algorithm generates a "stepped" waveform, with quite a lot of high-frequency harmonics and artifacts present. The Post Filter can smooth these out a little if you like.