The instruments could only come near a 303 with a Chip, a Filter and
two envelopes. The biquad filter does not saturate, every note strikes
anew, and there was no slide and no accent.
- Acid is a new instrument node that plays a saw or a square through a
four-pole ladder low-pass with tanh saturation, oversampled twice.
Knobs: cutoff, resonance, env mod, decay, accent, tuning and slide
time.
- An accent comes from the velocity, from 0.9 on. It is louder, opens
the filter further with a shorter decay, and accents close behind
each other build up.
- Two notes that touch or overlap slide. Each note stays a voice of
its own, so the scheduler is unchanged. The notes of a line share
one synth in the worklet, and the new voice takes it over from its
first sample on.
- The node sets its own volume, so it needs no envelope behind it.
- The graph shows it as a device with the filter curve at rest and at
the top of the sweep.
- A preset Acid Bass puts an Acid in front of a short echo.
Tests:
- tsc, eslint, Prettier clean
- Unit: 14 new tests in acid.test.ts for pitch, low-pass, resonance,
sweep, accent, slide and the handover between two voices.
- e2e 34 on melektaus-atx: ALL PASSED, 148 checks (3 new). The
handover sits on sample 4800 and jumps by 0.0012, of three notes
only the second slides.
- Without the handover, or with a slide that strikes anew, the unit
tests are red.
- Gate on melektaus-atx: tsc, eslint, Prettier clean, 4753 of 4754
tests green. The red one was sound-library.test.ts, which did not
know the new slid count in the stats. Fixed, and the file alone
is green again with 128 tests. No second full gate.
- Not checked: the sound by ear, slide at the keyboard, a bake with
Acid, the CPU load of many notes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
adminandClaude Opus 5.5
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