High Definition CD or HDCD - What is it exactly?


I have an Audio Aero Capitole MKII and always thought it had the ability to read HDCD's. I thought this until recently playing an HDCD on a friend's CEC CD player which has a small light that appears that tells you that it is reading the disc as an HDCD. The improvement and realism in the sound was awesome. The realism in sound reminded me of SACD in many ways, although I don't have much listening experience with either HDCD or SACD.

What exactly is HDCD and why can't the Aero Aero (at this price point) play/read these types of CD's?

One more thing...I burned a copy of the HDCD, but the CEC player did not recognize the copy as an HDCD.

Your comments are appreciated. Thanks,
128x128gerryn
I think Dusty Vawter of Channel Islands Audio eschews HDCD decoding in his DACS because the HDCD D-A chips don't sound as good as he wants them too.
I don't think I'm mis-paraphrasing him - Just another side of the coin to consider.
My HDCDs are the best sounding ones I have, on my compatable player.
Tobias, that's the clearest explanation I've read.
I've been a big fan of HDCD for sometime. My first experience was with Joni Mitchell's "Blue," amazing depth and deail. I have noticed many unmarked cds are HDCD encoded with no indication on either the label or cd. There is a thread listing favorite HDCDs here and a rather lengty one at audiocircle.
One of my favorites is Stepen Stills "Manassas."
Alpass -- this site has the most extensive HDCD catalog I've run across. It's a Swedish site (I think) but has an English language option:

http://www.hifimusic.se/hdcd/?p=home&lang=en

.
BTW, the HDCD license that the manufacturer needs in order to sell a player with an HDCD decoder requires that the player have an indicator for HDCD disks. It also requires that the level of non HDCD disks be 6db lower than HDCD disks. Some manufacturers put a defeat switch inside the player for this gain reduction - it doesn't violate the license if the end user disables the gain reduction.

For a long time Pacific Microsonics would not grant a license for a software implementation of HDCD (I.e. Wadia, Theta, Krell, etc) - you had to buy their decoder chip (PMD-100 or PMD-200). I think that stance has shifted since Microsoft bought them.