MATHS Trigger Input makes a fixed 0-to-10V transient, while Signal Input makes a sustaining envelope that tracks gate level

MATHS Channels 1 and 4 have two separate inputs with different envelope behaviours. The Trigger Input generates a transient: any gate makes the output rise from 0V to 10V then immediately fall — there is NO sustain. The circuit re-triggers during the fall but ignores triggers during the rise (which is what enables clock division). The Signal Input is direct-coupled: a gate here creates an ASR (Attack-Sustain-Release) function that rises to the gate’s level, sustains while the gate is high, then falls when it goes low. Choosing the wrong input is a common patching error: a held-note sustain needs the Signal Input, not the Trigger Input.

Examples

A clock pulse to the Trigger Input = an AD envelope per hit. A held gate to the Signal Input = an ASR envelope that sustains for the duration of the note.

Assessment

You want an envelope that sustains while a key is held. Which MATHS input do you use, Trigger or Signal, and why does the other one not sustain?