wha vox pedal

i want to plug my wha-wha pedal between my mpc and my computer.
I want the wha to affect sample as i play them on the mpc.
Any clue about the impedence problem?

There shouldn't be an impedance problem, the MPC has high level, low impedance outputs and won't have a problem. You might want to watch your level though, too hot and it could cause problems into the wah.