Do you have the MPC Editor Program? $30, converts Wav to SND and you can create programs lay out the samples on the pads how you want, edit envelopes, filter, tuning etc right on the screen. Then export the PGM and SND's to a zip and load it into your MPC3000!!!
It is for PC, if you are on mac, you can use the PGM maker, which I think is free, but not as extensive (from what I hear)
I do it all the time on my 60, which I have to export the Editor PGM's as 3000 files, which the 3.10 OS reads and converts to 60 format.