I'm an electronics technician, and I'm not sure :-)
I think for one thing it would depend on the type of pedal.
Boss pedals all use input buffers that I believe adjust to impedance coming in.
Boxes with volume controls I wouldn't think would have a problem you just make
sure you don't overload the input. I've got an An1x and as a guitarist...lots of
stomp boxes. I seem to recall a long time ago trying like a phase shifter off of
a line device keyboard.
I think you might just try it out and see?
Jim
====================================================
Check out my original music at
http://www.soundclick.com/bands/1/jackermusic.htm"In theory there is no difference between theory and practice,
but not in practice."
====================================================