BugBrand PRC2B Noise Crusher

The Noise Crusher is a versatile modular clocked sample and hold. Like many sample and holds (S&H) it offers a white noise source and a clock together with the S&H itself. But leave it to Mr. Tom Bugs to design a superior module.

One superlative feature is the wide range voltage controlled clock. It sports square and sawtooth wave outputs, both 0-10V in size. One CV input is attenuated, the other is 1V/octave. There is even a sync input. It has two ranges, Hi – 10Hz to 90kHz and Lo – 0.025 Hz (40sec cycle) to 90 Hz. And there’s a bi-color LED which pulses red to green at low rates and glows red at high rates. It’s a full-feature VCO/LFO, only missing the temperature stability of VCOs like the SYN2A or SYN2B.

A panel switch selects the internal clock or an external clock.  Another switch selects between the white noise as input to the S&H or an external signal to sample on the yellow jack.

The other superlative is the S&H itself, which is designed to operate in two modes, Lo and Hi, selected by the same range switch as the clock. The ‘crusher’ moniker refers to the notion of bit crushing or sample rate reduction. In Hi range, the Noise Crusher bit crushes any audio frequency signal at the input. At the sample rate maximum of 90kHz, the incoming signal is sampled so quickly that it’s virtually passed as is. However, as the clock rate falls into the audio range it begins to modulate the input in a way that is different from either frequency or amplitude modulation. The demo recording below gives some idea of what it sounds like. In Lo range the PRC2B works wonderfully as the classic sort of sample and hold we all know and love.

Side view of module

Side view

Rear view

Rear view

This recording demonstrates bit crushing a pure sine wave (supplied by the BugBrand SYN2B VCO). All sound is coming from the SYN2B or the PRC2B. I used two other LFOs to demonstrate modulation. Different effects are obtained by modulating the sine VCO, the crusher clock, or both. First you hear the pure sine wave, then the sawtooth output of the Noise Crusher, and then you hear the sine wave crushed at the frequency of the sawtooth. The next thing you hear is the sine wave modified by a slow triangle LFO and then the Crusher sawtooth modulated by a faster falling ramp LFO. Finally I play around with the CV attenuators and the initial sampling frequency to give some idea of sounds obtainable by voltage control.


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