Upsampling seems to be all the rage these days, but few people realize that upsampling was another one of those dCS "firsts" – and it was discovered by accident. dCS made a professional digital converter, the 972. It was never intended to "improve" performance. It simply facilitated the conversion of one data format to another, something recording studios need to do all the time. When customers began reporting back to dCS that a conversion from 16bit/44.1k to 24/96 actually improved performance, dCS began to investigate.
Whether it was the extra stage of jitter removal, the ability to use
gentler filters at the higher sample rates, or the interpolation, there did seem to be a
significant increase in performance. Images were more stable, soundstages more defined,
and the sound was… well… just less "digital."
dCS then designed the Purcell, a product based on the professional 972, but tailored to the needs of the music enthusiast. Then, in typical dCS fashion, they began to push the limits. dCS became the first to upsample to 192k, and today they are the first (and so far only) to "upsample" to DSD, the format used for SACD.
Today, in most systems, we find that conversion from 16/44.1 to DSD provides the best overall result, providing near SACD performance from your entire CD collection.