Quote Originally Posted by noddin0ff
I follow now. I can't imagine that there are HDCD's out there that were 'upconverted' from 16/44.1 sources. I assume they are all from higher res masters, maybe I'm wrong. I don't own any HDCD's that were re-releases.
Actually HDCD is of no benefit to 20 or 24bit bit depths. It takes 16bit signals and re-encodes them to approximate 20bit depth. This practice would be redundant on signals that are originally recorded in 20bits, and a degredation of 24bit signals.