Noise gate on delay tails triggered by dry signal?

[Chris S]

I'm looking for a way to put a noise gate on the wet signal of a delay, but I want it to be triggered by the dry signal so as soon as I stop playing guitar the wet signal gets muted. Is there a delay that does this or a way to split up a noise gate? Thanks!

[BluffChill]

You'd need something like an envelope going into basically a VCA. Maybe envelope follower hooked up to a BJT-based VCA, with the delay path going through that?