I recently wrote about Blue Cat Audio’s Axiom amp sim plugin for my column in Electronic Musician. Included in that software is their Late Replies plugin, to be used for delay effects with your amp models. It allows you to modify its delays with a variety of built-in effects (filters, pitch-shifting, etc), as well as any of your AU, VST, or VST3 plugins!. And that is just the beginning; Late Replies is one of those effects that is more like an instrument. Check out these videos or download the demo and prepare to lose a day playing with the almost infinite parameter permutations.
Blue Cat Audio Late Replies