Strangelight Audio

1.4.1. Lesson 1: A playable voice

A voice turns each MIDI note into a tone with a start and an end. You need five nodes: the note's pitch sets the oscillator, and its gate drives an envelope that opens and closes a VCA.

Starting checkpoint: build-a-synth-start.tlpatch

  1. Click the Add node button (the + at the top left), type MIDI Input and choose MIDI Input. Click the canvas to place it on the left.
  2. Add MIDI Decode, Oscillator, ADSR and VCA the same way, from left to right. Leave room above or below each node for cables.
  3. Make these six connections:
From To
MIDI Input · MIDI Out MIDI Decode · MIDI In
MIDI Decode · Pitch Oscillator · Pitch
MIDI Decode · Gate ADSR · Gate
Oscillator · Signal VCA · Signal
ADSR · Envelope VCA · Gain
VCA · Signal Audio Output · Audio In

Keep the default settings: a Saw waveform and ADSR Attack 10 ms, Decay 200 ms, Sustain 70% and Release 300 ms.

MIDI Input into MIDI Decode; Pitch goes to the Oscillator and Gate to the ADSR; the Oscillator runs through a VCA, whose Gain comes from the ADSR, into Audio Output.

A Playable Voice.

Result: each key plays its own pitch. The note starts as soon as you press the key and fades to silence over 0.3 s after you release it.

If a note never stops: either the Oscillator reaches Audio Output without passing through the VCA, or ADSR Envelope is not connected to VCA Gain. Check the last three rows of the table.

Checkpoint: build-a-synth-playable-voice.tlpatch