In several of my MaxForLive effects, I have examined what happens if you modulate a parameter that is normally not associated with that type of control. So there's a Limiter with an LFO, an Echo effect where the modulation of time is derived from Random Noise, and my most recent effect, 'Missing Echo' allows the feedback inside a delay line to be altered by an LFO.
Dopplator' effect, but that was based on a rounded pulse as the LFO waveform, and didn't have any panning facilities. 'Missing Echo' is much more in the mainstream sequence of my effects, and so has dual syncable independent LFOs for panning, plus a Limiter to keep things under control if you require it, and dual syncable independent delay lines, as well as dual syncable independent LFOs to modulate the feedback. Yes, this is a lot of LFOs, but those always were the modules I ran out of first when I used to play with modular synths...
'Missing Echo' can be downloaded from MaxForLive.com
Because I have several different variations on the Echo effect available (from www.maxforlive.com) then I'm going to be adding a special easy selection page soon, so that it is easier to browse through the different variants on the echo effect that I have produced.