Upsampling is a marketing term and the mathematical manipulation of the music signal is the same as standard oversampling techniques. The purpose of these resampling techniques is to allow the designer to use a gentler low-pass filter for attenuating the high band digital "mirror image" signal. There is also a process called word lenght interpolation which is usually done in conjunction with up/oversampling that changes the Red Book output 16 bit word up to a 24 bit format. It is important to note that no new musical information is added in this process, yet it does seem to slightly improve sound quality. There is no generally accepted explanation that explains this phonomena. The dCS website is a good reference on these issues.
As a practical matter, don't worry whether you equipment up, over and even no samples the digital signal. Well designed implementations of each design all sound excellent.
BTW, the MSB Platinum is a marvelous sounding unit. I use the Sony 333ES as a transport. When playing SACDs I feed the analog output of the Sony directly to an integrated amp. SACDs sound better than the Sony/MSB combo.
As a practical matter, don't worry whether you equipment up, over and even no samples the digital signal. Well designed implementations of each design all sound excellent.
BTW, the MSB Platinum is a marvelous sounding unit. I use the Sony 333ES as a transport. When playing SACDs I feed the analog output of the Sony directly to an integrated amp. SACDs sound better than the Sony/MSB combo.