You can check my emulated sp1200 sample set, I put some multiband ring modulation on the samples along with a multiband bit crush effect. I think it's the closest your gonna get, you might me able to emulate the ring modulation easily because it's a pretty straight forward ring mod with bit crush placed on top of it. But your never gonna emulate the frequency response exactly. or what i consider to be most of the great warm qualities the sp1200 gives. thats why I abandoned trying to emulate it exactly in my sample set and go for my own ring mod-bit crush effect dubbed to tape. Judge for yourself
http://www.mpc-forums.com/viewtopic.php?f=5&p=1502878I certainly don't think putting a ring modulator on your input would get even close to the entire sound though. When emulating the sp1200 in my sample set, I got the sense the sp1200 sound comes from a lot of different components and lots of minor things that come together to greatly effect the sound. Not 1 or 2 things that did most of the work, it's just such a unique sound.