Turning a reverb's diffusion fully down converts it into a delay, usable as a dry-free parallel effect

A reverb algorithm with a diffusion parameter can be made to behave like a delay by turning diffusion all the way down: without diffusion the reflections stay discrete rather than smearing into a wash, so distinct echoes emerge. Feeding it a copy of a source (rather than inserting it in the main path) makes it a parallel effect; because the dry signal is already present in the mix, the effect’s own dry level is taken to zero so only the processed tails return. Trimming low frequencies out of the return keeps the effect from muddying the mix.

Examples

VCV Rack: send a copy of the hi-hat to a VCA into Plateau (Valley); turn diffusion fully down so Plateau acts as a delay, take the dry signal to zero, roll off lows, raise size, and return it to the mixer. Trigger it sparsely (e.g. via a clock ÷64) so it does not clutter.

Assessment

Explain why lowering a reverb’s diffusion parameter makes it sound more like a delay, and why you set the effect’s dry level to zero when using it as a parallel send.