im trying to slave the 303 to the 500 so i can use the sp just for the effects. but cant seem to get it working. what do i need to do?

Read a book on midi. J/k but on the real the answer should be in the MPC 500 and SP-303 manual's midi section. Maybe run an audio cable out of the mpc and into the 303 and then a cable out from the 303 back into the mpc.

First your going to need a trs to rca cables. http://www.guitarcenter.com/Monster-Cab ... 1172757.gc
You can get one for 12 bucks. Connect that with from mpc outs to sp303 ins.

As far as the sp303 being slaved. i manage to only control one pattern at a time while a song is being played from the mp.

midi out from mpc to sp303, then go to your midi sync from mpc and set it to midi clock .

you cannot control the sp303 effects from the mpc. so the first suggestion might be what your looking for.

hi guys
i have an mpc 500 too, but i'm just a beginner with (1 week).
i've tried the midi connection for midi sync and it works fine. they start together. when i change bpm from mpc 500, sp-303 come on. like two friends .
but the friendship is no long as they don't commuicate by pads.
the mpc 500 got too many subparameters that at first you don't even see what. i put mpc 500 in "master"mode and after i check for midi channels...s**t, there are Track params to see for, Program too, and Midi/sync also just to find where were the midi channels to assign...i got lost after 5 minutes...after find those, i've also tried what is written in the sp-303 manual about midi connection in order to play pads, i've also change sp-303 midi channels, but nothing happened...

too much subparameters, but at the end it works!