Audio Damage - Proton

Although the Proton makes for a pretty nice delay its main focus of attention is a type of physical modeling called Karplus-Strong synthesis. It creates percussive sounds which resemple a plucked nylon strong but Proton is able to twist them in a strong way by filtering and by adding noise impulses.

The sound is fired by a trigger or by pressing the button, making the module resonate. The pitch is tuned with "Pitch" as well as "Fine Tune", it can be played tonally via the 1V/octave input and modulated by the FineTune CV input.

"Damping" and "Decay" work together, being responsible for the release time, or in other words the duration of the sound. "Damping" sets the cutoff frequency of a low pass filter in the feedback path, "Decay" dials in the feedback amount.

IMP stands for the noise burst impulse which excites the delay core. "IMP Filter" filters this impulse, being a low pass filter left of the 12h position and a high pass filter to the right of it. "IMP Decay" determines the decay time of the envelope which shapes the noise burst. Especially when combined with open damping it produces interesting noisy, metallic sounds

Karplus-Strong loses amplitude in the low range for which reason Proton features SUB, a sine wave tuned to the fundamental which can be mixed with the physical modeling sound.

A trigger or a gate at the "Choke" socket supresses the delay, just like a hihat pedal.

"MIX" is connected directly to the "input" socket which allows for exciting the Proton by external audio signals and to mix them to the Karplus-Strong sound.
But the audio input also makes it possible to use the module as a digital delay. In this case "Pitch" and "Fine Tune" control the delay time, "Decay" the feedback amount and "Decay" the harmonic content of the feedback.