remember that 50% of the end result is due to a good post-production (compression, harmonyzer, dynamizer, etc.. all the studio effects).
That's why you hear it so loud and clean, so edgy.
Pre-order a Yamaha RS7000 and you'll have basically what they use... I have a feeling that timbaland is simply using an old AKAI MPC3000, like most of these rap producers. The RS should even be better.
but again, after you produce, the way the master is done is when yoru sound is there or not there.