Practice Session
Page 6 of 11
Using Pachinko (Marbles clone) as a clock. Topic from a session with Matthew.
A collection of SVG album cover illustrations generated by Claude Code — abstract interpretations of iconic electronic/ambient albums.
The core concept is elegant: a gate signal has a sharp transient attack followed by a sustain and release. By driving the QPAS’s radiate/resonance into self-oscillation, you can treat the filter itself as a pitched sound source, and then use the gate (often via an envelope) to excite it — like physically striking a tuned resonator.
The QPAS has a pair of bandpass filters in a stereo configuration with its unique Radiate parameter controlling the interaction between them. When you push Radiate high and increase Q (resonance), the filters approach and eventually enter self-oscillation — they ring at their cutoff frequencies like tuning forks.
A short trigger or gate sent to the audio input (or used to modulate the input level via a VCA) causes the filters to “ping” — they ring out at their tuned frequency and naturally decay. This is the same physics as hitting a bell or a drum: an impulse excites a resonant body, which then decays at its natural frequency.
Basic patch:
Kick drum: Tune QPAS low (60–100 Hz range), hit it with a short impulse, then modulate the cutoff frequency downward with a fast envelope (pitch drop is key for a convincing kick). The Zadar is great here — use one channel as the audio envelope, another for cutoff CV with a sharp initial peak that falls fast.
Tom / resonant thud: Slightly higher tuning, slower pitch envelope decay, moderate Q. The QPAS’s stereo bandpass character gives toms a rich spatial quality that mono filters don’t.
Hi-hat / snare-adjacent texture: Mix noise into the input, tune QPAS higher, use very short gate/envelope. Adjust Radiate to spread the stereo image — high Radiate creates a nice wash. Adding both cutoffs spread apart creates a more complex, metallic texture.
Clap / transient crack: Very short ping, fast envelope, mid-high frequency, high Q but not quite self-oscillating. The transient becomes the sound rather than the sustain.
Cowbell / metallic perc: This is where QPAS really shines. Because it has two filters, you can tune them to non-harmonically related frequencies (say, a minor 7th or minor 9th interval apart). The two pitches beating against each other create that characteristic metallic inharmonicity. Push Radiate to control how separated vs. blended they are.
The QPAS has dedicated CV inputs that make this really playable:
Deep dive into Clicks & Cuts — a movement in experimental electronic music where artists deliberately embraced digital errors, glitches, and sonic artifacts as primary creative material. Named after the Mille Plateaux compilation series (2000).
Microscopic clicks & pops, digital buffer glitches, extreme frequency exploration, pointillist textures, dub-influenced bass and space, granular clouds, and silence as a compositional element.
The original C&C movement was largely laptop/software-based — the modular world inherited and evolved the aesthetic as Eurorack exploded. These artists bridge the two worlds:
Notable hardware: Møffenzeef Mødular built Eurorack modules specifically for clicks & cuts style glitch percussion.
See the full Clicks & Cuts mood board for the complete timeline, discography, labels, and visual language reference.