Is it the transport or DAC that enables HDCD/Red?

Add the Esoteric P-70 and I believe the D-05 to the list of DACs that support HDCD. The Classe SACD-1, SACD-2, and several Cary players also support it.

Kijanski - there's much more going on with HDCD than dynamic range switching. The recording is made at 88.2 khz/18 bits. It is then analyzed by the HDCD encoder which decimates the signal to 44.1 khz and applies on a moment by moment basis the selection from a suite of encode processes (compression, filtering,etc) that best preserves the characteristics of the original signal. The encoder also modulates the low order bit to tell the decoder which inverse process to apply at any moment. The result is a 44.1 khz/16 bit data stream that can be played by any CD playback system.

On playback the HDCD decoder reads the low order bit modulation pattern and applies the appropriate inverse process on a moment by moment basis to create 44.1 khz/18 bit data stream from the 16 bit data stream off the disk.

One other important feature - the filter in the decoder is a perfect conjugate of the filter used in the encoder, which by itself improves fidelity.

The intent was to do most of the number crunching on the encode side while the decoder remained simple.

The only responsibility the transport has is to provide an exact copy of the bitstream encoded on the CD (another argument against those who whine about CD data errors - none of this would work without perfect recovery)

Look up other threads on this.

As to the original poster's question about small footprint dacs that decode HDCD, the only brand I'm aware of are the Assemblage 2 series. They were in a half width chassis like PS Audio uses for their current small component series. I've got one of their last ones manufactured, a 2.7 Platinum and it still sounds very fine. With an HDCD disc (and some redbooks,) I still prefer it's sound to the sound of the internal dac in my Marantz Sa11S1. As to Kijanki's question about non-hdcd vs redbook cds of less than stellar quality, the Doors are available in some HDCD issues. You could compare Rhino's redbook remasters to the English HDCD remasters to make a comparison, although not an exact one.

Ghostrider45 - All CDs are made from higher number of bits from master tapes thru decimation to 16bit/44.1kHz. Bit nr 16 (LSB) switches dynamic range of the other bits but it cannot play well on redbook CD player since it has no way of knowing what is playing and will play with weird dynamics.

Whole scheme assumes that in loud passages you can't hear resolution of quiet instruments. Theoretically it supposed to work but I read opinion of recording engineer that it sounds a little strange.

Photon46 - I don't have HDCD player and asked if anybody listen on the same unit to exactly same issue of, for instance, Doors that you mentioned, in CD and HDCD.
When it says that older disk was remastered for HDCD sound in general could be improved. It's like comparing regular and remastered Doors album.

Bob - do you have ability to play HDCD in non-HDCD mode (redbook)? How does it sound?

You can probably guess my intentions - I'm trying to find what killed the standard (it's dead - isn't it?).