funkycoldmedina wrote:Lots of audio pops during playback, certain pads are now tuned differently, pads aren't cutting each other off when they're in the same mute groups...
What exact Mac OS version are you running? These are not common bugs in the MPC Software itself, most people are running 1.9.4 in a Mac without any such problems. If you are on Mavericks or newer, I'd be tempted to consider trying a fresh Mac OS installation and see if the problems persist.
By that I mean take a USB3 drive, install a fresh copy of OSX on that (Mavericks or newer), boot up from that USB3 drive (hold down the option key during boot up), install the MPC Software (1.9.4) and nothing else on that drive, do not attach any other peripherals, and see if all runs smoothly. If it does work fine, then you know it's a conflict with something on your older OS set up, so reintroduce other hardware and software apps & plugins one at a time and monitor any adverse changes.