Meng Qi Rollz-5 | Peter Blasser circuit design

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Saint Louis, MO, United States
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"Ancestor of the Plumbutter" and it definitely shows. Great unpredictable and experimental "drum machine" (as much as you can call anything Ciat Lonbarde that). The one issue I've had is the left ultrasound section is very low output. The case shows wear and debris hence the "good" quality.

Also, not built or modified by me. Comes with power supply.


Rollz-5 is , it is the ancestor of Plumbutter. It is can be understood as a Drum Machine, but not quite.

Instead of sequencer on most drum machines, Rollz-5 implies geometric rolls that outputs pulses in different paces, set by component values while building. Even rolls would produce rhythmical signals while odd rolls would yield high frequency oscillations. The rolls can be connected together to form complex rhythms and audible signals.

Then the signals from rolls will be connected to 3 different sound modules, following descriptions are taken from Peter's website :

  • AVDOG : which uses the same resonant filter as Gongs, but at a very low frequency, to transform pulses into a slow undulation. This undulation controls the amplitude of a simple drone tone, to make a ghostly complement to the pulse material. I created this translator to balance with the plucked and pulsed sounds. It’s like sending pulses through a watery wave-tank which speaks a simple tone, a complement to the more abrupt rhythms of the other translators, yet it relates periodically because it is based on the same raw material.

  • ULTRASOUND : knob sets the cutoff frequency around which ultrasounds are reflected down to audible range. It uses a switched capacitor filter, which has a (happy) side-effect of heterodyning high frequency sound by its reference tone. It sounds like an old-time radio as it sweeps through stations; there are audible difference tones swooping up and down. This translator also filters the timbre of the even pulses.

  • GONGS : It works with even pulse material, waiting a period set by the control knob, then pulsing a resonant filter preset to a certain pitch and damping. Normally I would desire moveable pitches, but I reconciled with set pitches because this is a drum machine- The tones mark phrases around which melodies develop externally, and I would rather control the phrase length than the tone of the gong. Anyhow, a creative hacker could easily mod these circuits to make the pitches moveable.  The sonic effect is anything from a short woodblock tone to a long deep resonant gong, synchronized at short or long periods.

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