Stereo/Mono

Hey everybody, I have to start saying that I 've always found it to be extremely annoying to sample certain drums from records cuz there are so many breaks that just sound like shit when you chop them. The thing that drives me nuts is the noise between the hits and even a good cutoff or decay setting will not get rid of noise or allow the sound to come out properly. I'm pretty sure I'm not the only one that thinks this way .So Lately I'e been trying to bring things back to basics cuz I noticed that I've been doing certain things wrong .Like for example I always thought that If I panned my mixer out to the left channel that the master for given channel would be coming out on given channel exclusively but apparently I'm just cutting out one of the chanels .
The question is, how do you get your stereo signal recorded directly to mono(integrating both chanels) on your MPC with the regular (2x)RCA to (2x)1 1/4 jacks??This is on some rookie type shit and I can't believe I was doing shit like this ....