Can I lay down a loop and then apply delay to the loop on playback?
Because you have to select between delay OR looper function with the delay type selector on the pedal, this is simply not possible. In contrast, it is possible to do that with the Alter Ego X4. And even more!
Using the Alter Ego X4, if you put the mini toggle switch to "LOOPER" position you can chose any delay effect you want with the delay type selector knob. Setup the delay parameters the way you want using the knobs on the pedal:
The delay you have chosen will be recorded with the loop (this cannot be applied later). You can modify the settings during recording, it will be recorded with the loop as well. Because the delay effect has been recorded with the loops, once the loops are in playback mode, you can choose a completely different delay to use while playing live over top of the loop.
The only limitation is that you cannot select a preset because in looper mode, the footswitches are used for looper functions.
You can setup the mix of both loops and direct delay effect with the Looper Level knob on one side and the Delay level knob to the other side.
This is possible also with the Flashback X4.