RPD wrote:Audacity.
Why buy an mpc if you aren't going to use it for it's full potential?
It's not like he's chopping with a buttery scroll cursor like an XL. I wouldn't hold it against anybody that doesn't want to chop on a 500. At the same time I get that some people like to chop in the machine even when it's straight old school by ear with only numbers/frames to guide you. Also the upside to letting your ears guide you rather than a graphic. But many times you want to chop on a dime and do it quick so I feel where the OP is coming from.
Audacity is definitely a good call but here's an even more specific tool.
http://sourceforge.net/projects/mpcmaid/files/It lets you drag and drop samples to make 500 and 1000 PGM's. It also will let you load a loop/break and chop it and auto assign it to the pads. You have to toggle a switch so it knows you want a 12 pad 500 PGM. It's free, on Windows you need Java Runtime Environment on your system (likely already there), not necessary on OS X.