Looping for rehearsal, record/listen/record/ ...

[Michael Ellis <michael.f.ellis@gmail.com>]

I'm looking for a software or inexpensive hardware solution for the
following seemingly simple task:

Record a bar or two of playing (fiddle, fwiw)
Listen to what I've just played
Record another try,  listen,  etc.

The catch is that I'd like it to be hands-free and, optimally,
foot-free and and in continuous rhythm.  In other words I'm looking
for a setup that will allow me to specify a fixed duration and then
begin alternating automatically between recording and playing back.

I currently own a Boss RC-20XL.  It can do a great many things, but
not this.  I also have the very cute Everyday Looper app on my iPhone.
 Again no luck with this particular task.

This is for rehearsal only, so audio quality is less important than
convenience.  Anyone know of a (preferably cheap) solution?

Thanks,
Mike