depends... if they are drums.. sample it mono... if its a vocal hook or something that has reverb on it ,stereo. It really all depends on how much memory you have. but like I said for drums (I) always do it in mono but you can do it however you need to also you save on memory if you do everything in mono.
i sample both stereo and mono the only diffenece i can tell is in my mixer,my mpc runs into , some times i need to switch wires,(not often)but that cuz i'may have my mixer wires all jacked up.
dont matter thou cause all i want to do is f#ck with the mpc.
you kno i just noticed your not going directly into the mpc are you, you need a mixer to go in between the turntable and the mpc your samples wont sound good going directly in to the mpc,
the difference in sound between the two stereo you hear wider sound(both speakers)
mono you hear a duller sound out of both speakers (mono meaning one speaker)
Do you understand the basics of PANNING your sounds to place them with in a stereo (2 channel) fild AKA between your left and right ears. This is key inorder to create and define sounds within a liseners precived lisening space. If you listen to most old records certin sounds are paned to the left and others centered or to the right. This is key in sampling because if you hear a funky GT riff panned to the right you can isolate that and use it without all the other instuments full volumes bleeding in from the left. This can be done if you sample in stereo or have a mixer with a pan pot. If you sample in mono all the sound from the left & right channels (stereo) will be combined into one channel (mono) and you will not be able to isolate any sound.