Ok…D has made THE point!
I have used Eventide Reverse delay and shifter for the last 15 years, thru H3000/Orville/Eclipse/H8000 and all other units. There are basically 2 ways you want to use a reverse fx:
-playing IN TIME
-playing FREE…NO TIME
Playing in time involves the use of TapTempo/MIDI Clock
pretty much as any delay type, Reverse delay requires a buffer memory to be filled with datas (= what YOU play) and sending it out exactly after the choosen buffer length (delay time you set). So, for example, if your song has a 120 BPM beat and you want a reverse delay of a quarter note, set TTempo on 1/4 note and the dsp will automagically set delay time to 500 ms. Now you need to play *in time* with the song beat.
when playing without TIME, which is what I love the best, set your reverse delay to long settings, from 1500 ms on and just play. No dry sound! Your playing will be back after the set delay time…just keep on playing and things will sound right.
A "hybrid" approach is to set the delay time as long as possibl, in relation to the song beat. A whole bar or more bars….. that is another amazing way to use this cool fx.
Be aware that reverse fx will NOT instantly play what you play. It is not reversing your lines in real time. It always require a memory (=delay time) to be used/filled/released.