#waveform
- Pulse width modulation (PWM) techniqueA pulse wave's character depends on its duty cycle: 50 % is hollow and round, 25 % brassy, 12.5 % thin and nasal. Sweeping the width while a note plays makes a single channel sound alive — the classic C64/ sid shimmer …
- Ring modulation and oscillator sync techniqueTwo of the sid 's control-register bits couple a voice to its neighbour: sync ( $02 ) hard-syncs one oscillator to another, ring ( $04 ) replaces a voice's triangle output with a ring-modulated combination of the two. …