A three-voice chip synth emulating the MOS SID, the home computer sound chip, through the reSID core.
Inlets
MIDI
1
Outlets
Audio
2
Both the original 6581 and the cleaner 8580 revision are emulated cycle by cycle, analog filter included. Three voices share one filter as the hardware did; a fourth note steals the oldest voice. Every voice plays the same wave, pulse width and the chip's own four-stage envelope in its native sixteen steps. Pitch comes from the patch tuning to the resolution of the chip's frequency registers, so a microtonal scale plays. Twin mode adds a second chip, as the modded boards did, doubling every note with the pair detuned across the stereo image. Play it over a MIDI cord from a PianoRoll, DNA or MidiIn, or with the keyboard while its editor is focused.
Parameters
Model
Which chip: 6581 with the warm, wayward filter, or 8580 with the corrected one. Switching fades the level in briefly to soften the step between the two chips' resting voltages.
Wave
TRI, SAW, PLS or NSE, the chip's four waveforms.
PulseWidth
The pulse wave's duty cycle. Only audible on PLS.
Attack
Envelope attack in the chip's sixteen steps. 0 is instant.
Decay
Envelope decay to the sustain level, in sixteen steps.
Sustain
The level held while the note is down, in sixteen steps.
Release
Envelope release after note-off, in sixteen steps. 15 rings for seconds.
Cutoff
Where the filter closes, across the register range of the hardware.
Resonance
How hard the filter sings at the cutoff, in sixteen steps.
FilterMode
LOW, BAND or HIGH pass.
Filter
Takes the filter out entirely for the raw voices, brighter and louder.
Ring
Each voice ring-modulates with its neighbour, metallic and clangorous. It speaks through the TRI wave.
Sync
Each voice hard-syncs to its neighbour.
Chips
ONE chip, or TWIN: every note on both chips, one leading each side with a little of the other blended in.
TwinDetune
How far apart the twin pair is detuned, in cents, straddling the note. Shown as Spread.
Chain
Wires the first chip's output through the second chip's filter, so the left side arrives dry and the right side through a second analog filter. TWIN only.
ModelB
Which chip the second one is, B 6581 or B 8580. Mixing a warm original with the clean revision is half the point of two.
Level
Output level.
BendRange
How far the pitch wheel reaches at full travel, in semitones. Two is the common default; zero ignores the wheel.
Recipe
Chip bass
Model 6581, Wave PLS, PulseWidth 0.25, Attack 0, Decay 9, Sustain 6, Release 5, FilterMode LOW, Cutoff 0.45, Resonance 8. Cord a Riff to the MIDI inlet and add an LFO onto PulseWidth at a quarter of a bar for the classic pulse sweep. Switch to TWIN with TwinDetune 8 to widen it.
