A Glicol feedback bus with gain ≥ 1 explodes — keep loop gain below 1

In Glicol, a ~bus that references itself creates a feedback loop. If the gain around that loop is 1 or greater, the signal accumulates without bound and clips hard. This is the same contraction requirement as GLSL and Hydra feedback: the recurrence must scale down each pass. The fix is to insert a >> mul 0.6 (or any value < 1) inside the loop. The clipping is abrupt and can be very loud.

Examples

~fb: ~fb >> delayms 300 >> mul 0.6 // safe feedback echo ~fb: ~fb >> delayms 300 // gain=1 → explodes

Assessment

A student creates ~echo: ~echo >> delayms 200. Predict what happens and modify the chain to create a decaying echo instead.