HDCD -- playback options for hardware decoding and digital output
Aug 28, 2008 at 10:13 AM Thread Starter Post #1 of 15

emmodad

100+ Head-Fier
Joined
Apr 8, 2007
Posts
163
Likes
12
so there have been several threads on Head-Fi that in one way or another touch on options for HDCD decoding. Many of us unfortunately couldn't afford the USD 15,000.00 typical price for a used Pacific Microsonics Model 2 -- even if we could find one for sale (hint: rather rare). A Berkeley Alpha DAC would be a great option too, many thou$and$ less than a Model 2; however I am specifically interested in a system architecture which permits feeding decoded HDCD to whatever DAC (or DACs) I choose. And less expensive is indeed not to be dismissed... more money for music...

I've been exploring various options to send a hardware-decoded HDCD data stream to my DAC of choice. Currently the most cost-effective appears to be use of an Oppo HDMI output plus hardware providing legal means to access the HDCD-decoded 20/44.1 audio datastream.

One boundary condition for this investigation: although there are perhaps some older out-of-production items of consumer electronics which had HDCD decoding, I'm more interested in looking for solutions which use currently-available products.

---

After having ripped/decoded HDCD for some storage/server experiments, the desired use scenario is twofold:
1/ decode HDCD from spinning discs, output decoded datastream to DAC

2/ decode HDCD from an input 16/44.1 datastream (ie from a music server), output decoded datastream to DAC
---

Scenario 1 is supported by a CD / universal player which provides decoded HDCD on a digital output. To my knowledge, this is currently only available from:
Oppo 980 / 983 via HDMI (from which the 20/44.1 audio stream can be accessed)

Cary 306 SACD Pro (decoded HDCD appears as 2x/44.1 on digital outs; not sure if "2x" is 20- or 24-bit)

Oppo (and perhaps other such as Denon, Rotel, ...?) CD & Universal disc players which incorporate HDCD decoding and which are modded with aftermarket digital output boards that branch off audio (incl decoded HDCD at 20/44.1, and perhaps some at 24/44.1 or 24/88.2) at input to the player's DAC IC. This means the player must have an architecture where HDCD decoding takes place in a processor before (and outside of) the DAC IC which follows; architectures which use chips where the HDCD decode function is integrated into the DAC IC can't use digital output mods (unless of course that HDCD+DAC chip has output pins providing signal tapped just before input to the DAC section)

Question: are you aware of any other unmodded commercial players which are confirmed to natively output decoded HDCD on either HDMI, SPDIF (TOS or preferably coax) or AES/EBU XLR?
Scenario 1 could also be supported by a reasonably-priced receiver or pre/pro which accepts 16/44.1 digital input from a disc player, incorporates HDCD decoding AND will output the decoded HDCD signal to a digital output.
Question: are you aware of any receivers or pre/pro units which natively output decoded HDCD on either HDMI, SPDIF (TOS or preferably coax) or AES/EBU XLR?
---

Scenario 2 requires a unit which has digital input, incorporates HDCD decoding and will output the decoded HDCD signal to a digital output (ie, like the receiver or pre/pro possibility described above).

As some disc players are now incorporating extra digital inputs (allowing the product to act also as a digital source selector and "standalone DAC" for those digital inputs), this is becoming an option.

For example, Cambridge 840c has these I/O capabilities but no HDCD decoding.

Cary 306 SACD Pro is confirmed to decode 16/44.1 HDCD from digital inputs and provide that decoded HDCD on digital outputs when no upsampling is selected (ie user selects 44.1 output fs). As an aside, no confirmation yet from Cary whether this output would be 20/44.1 or 24/44.1 (not really an issue); also do not yet know if the Cary will accept and decode 24-bit HDCD signals (ie the new Reference Recordings HRx 24/176.4 files).
Question: are you aware of any other disc players with additional digital inputs which will decode HDCD streams on the digital inputs and output that decoded HDCD on either HDMI, SPDIF (TOS or preferably coax) or AES/EBU XLR? Do you know if the units will handle 24-bit HDCD?

Question: are you aware of any receivers or pre/pro units which natively output decoded HDCD on either HDMI, SPDIF (TOS or preferably coax) or AES/EBU XLR? Do you know if the units will handle 24-bit HDCD?
---

Overall, I'm looking at the moment for three functions as I evolve my 2-channel system:
i/ digital source selection of 1 disc player plus minimum 3 other digital inputs, all capable of 24/192.

ii/ HDCD decoding as described in scenarios above

iii/ excellent 2-channel SACD playback
To do /i/ correctly (ie 24/192 bit-perfect, reliable and durable) as a standalone function means spending somewhat more than an inexpensive selector -- generally USD 3-500 for a broadcast-quality digital source selector. And more cables.

As for /ii/, a modded player that will output decoded HDCD from spinning discs can be had for under USD 500. I haven't performed an exhaustive search wrt units that will decode and output HDCD streams, but the only obvious solution seen thus far is the Cary (retail price USD 8000).

(aside: I've checked with Oppo, but unfortunately the 98x series USB input does not support uncompressed or lossless audio formats -- only compressed files like mp3, aac, ogg. A shame, as that would have been a very low-cost solution.)

And of course /iii/ costs whatever one is willing to spend to meet your personal expectation wrt SACD playback.

---

Would very much appreciate the contribution of any information concerning other hardware which addresses the questions and scenarios above.

thanx!
emmodad
 
Aug 28, 2008 at 10:55 AM Post #2 of 15
Huh?

Before I got my Denon two-tray HDCD player/recorder, I used one of my CD players to feed digitally to my Marantz reference-series HDCD recorder/player, and it then plays the HDCD perfectly, same as the original HDCD disk I copied.

From what I remember technically about HDCD, is that one of the existing CD bits is coded with values that are expanded with an HDCD DAC to give the expanded analog output -- meaning that an HDCD disk can be copied by any digital stream into any CD recorder, and the HDCD is retained in any case -- it simply takes playing through an HDCD DAC in a player to expand it and hear the proper sound.

I've recorded lots of HDCD with no problems, and it always retains the HDCD format in the copies.
 
Aug 28, 2008 at 12:04 PM Post #3 of 15
Quote:

Originally Posted by silverrain /img/forum/go_quote.gif
Huh?

Before I got my Denon two-tray HDCD player/recorder, I used one of my CD players to feed digitally to my Marantz reference-series HDCD recorder/player, and it then plays the HDCD perfectly, same as the original HDCD disk I copied.

From what I remember technically about HDCD, is that one of the existing CD bits is coded with values that are expanded with an HDCD DAC to give the expanded analog output -- meaning that an HDCD disk can be copied by any digital stream into any CD recorder, and the HDCD is retained in any case -- it simply takes playing through an HDCD DAC in a player to expand it and hear the proper sound.

I've recorded lots of HDCD with no problems, and it always retains the HDCD format in the copies.




of course.


The topic of this thread is not "can one retain HDCD format compatability." That is obviously possible by copying CDs, or bit-perfect ripping HDCD-encoded tracks to Lossless Compression, reexpanding when burning new CDs, etc. Just as in your scenario.

However your CD player fed an encoded HDCD 16/44.1 stream to your Marantz reference-series HDCD recorder/player, which then either created a CD (directly at 16/44.1) which you played (as 16/44.1); or played the stream from your CD player directly in realtime (not sure from your wording).

In either event, HDCD decoding was performed inside your Marantz, and the decoded (ie expanded to 24/88.2 using whichever HDCD options selected by the mastering engineer; and possibly downconverted to 20/44.1 or 24/44.1 depending on the HDCD decoder functions) signal then went to the DAC IC (IC = integrated circuit aka "chip") inside your Marantz; analog output then came out of this IC, through the Marantz analog output stage and then out of your Marantz.

My goal is to bypass internal DACs and output stages, and deliver the decoded HDCD signal (20/44.1, 24/44.1, 24/88.2, 24/176.4, etc) directly to my external DAC(s) of choice:
HDCD-encoded digital input > HDCD decode > HDCD-encoded digital output > digital destination (ie external DAC)
In essence, what I am looking at are options to achieve hardware decoding of HDCD (ie realtime, full-compatibility as opposed to partial functionality in hdcd.exe or other software attempts); both for signals "streaming" off a CD and "streaming" from a music server.
The former (CD) requires only a disc player that can digitally output the decoded HDCD signal, which is sent to the external DAC.

The latter (server) requires a "box" that accepts 16/44.1 (or 24/176.4) HDCD-encoded digital input; decodes HDCD; and outputs decoded ("expanded") HDCD in the resulting expanded resolution and (perhaps) higher samplerate. Which is then sent to the external DAC.
hth
 
Aug 28, 2008 at 12:14 PM Post #4 of 15
Not sure what the heck you are driving at, BUT:

when I have copied an HDCD disk in a regular NON-HDCD Denon two-tray CD player/recorder, I can then play the recorded disk in any of my HDCD players, and gete HDCD playback.

Whatever else you are looking for, I have no idea, so over and out, for me.
Maybe someone else knows what you are looking for.
I tried.
 
Aug 28, 2008 at 12:29 PM Post #5 of 15
Quote:

Originally Posted by silverrain /img/forum/go_quote.gif
Not sure what the heck you are driving at, BUT:

when I have copied an HDCD disk in a regular NON-HDCD Denon two-tray CD player/recorder, I can then play the recorded disk in any of my HDCD players, and gete HDCD playback.

Whatever else you are looking for, I have no idea, so over and out, for me.
Maybe someone else knows what you are looking for.
I tried.



silverrain, here is your homework assignment, explain how you would set up hardware to achieve the following:

1/ rip HDCD-encoded CD, store files to server.

2/ stream files from server (which does no HDCD decoding, so files are still 16/44.1 HDCD-encoded) to a weiss DAC... or a Benchmark DAC-1 ... or a PS Audio DAC... or a Bryston DAC... or any other DAC you choose to use or test which does not have built-in HDCD decoding.

3/ have that target DAC be converting not the undecoded signal (16/44.1, HDCD techniques not used), but rather the HDCD-decoded digital data (at 20/44.1 or 20/88.2 or 24/176.4, with all dynamic range enhancement, filtering, and enhanced dither techniques utilized).

discuss.
 
Aug 28, 2008 at 1:24 PM Post #6 of 15
Last try:

Copy the HDCD disk, absolutely exactly the same way you would copy a normal CD.
If from external source to a recorder, use digital transfer cables (coax or optical).
That's all -- just normal CD copying techniques.

Only the DAC used for playback, will come into play for HDCD.

I even get HDCD playback on my Dell computer, with Windows Media DVD/CD player, and also from sample music files on Aamazon, when they contain HDCD music.

Your 3 questions specifically:
For 1) use above info I just typed
For 2) into a non-HDCD DAC, the HDCD coding will be lost after that, I think
For 3) into an HDCD DAC, output will be analog HDCD playback
 
Aug 28, 2008 at 2:26 PM Post #8 of 15
yes, you are unfortunately missing a few points:

1/ This is not about CD copying. Although the source for playback of 16/44.1 HDCD-encoded data could be from a spinning disk -- original or copied/cloned -- it could also be from ripped files stored on a server.

First, not all servers run Windows, so WMP is not even a cross-platform option to begin with. Further, the sytem requirements I am facing do not permit non-realtime or incomplete HDCD decode (hdcd.exe does not implement full HDCD decode functionality; WMP also has issues and may be phasing out HDCD compatibility (private communication)).

if the source is a CD, decode is done inside the CD player box, decoded signal passed to DAC inside the CD player box, and output analog.

If source is a server, complete HDCD decoding has to be done somewhere after the server and before the DAC being fed by the server. This means there has to be an HDCD decoder before the DAC. That's what I'm looking for input, concerning hardware options which take digital input, perform HDCD decode, and provide digital output.

2/ you said it yourself!: no HDCD decoding, then HDCD benefit is lost. Please re-read point 3 of my previous post: the objective is to have the target DAC of point 2 (a non-HDCD DAC) converting HDCD-decoded data.

The point of this entire exercise seems to have been stated clearly: how to implement full HDCD decoding between a source (server serving up 16/44.1 HDCD files, or a transport spitting 16/44.1 bits from an HDCD-encoded CD) and an outboard DAC which does not contain HDCD decode function (which, aside from a BADA alpha DAC and a few older out-of-production DACs, is pretty much all of them).
 
Aug 28, 2008 at 2:52 PM Post #9 of 15
*blinded by science*
 
Aug 29, 2008 at 10:18 PM Post #10 of 15
I think in a nutshell the OP wants a hardware appliance to decode the HDCD stream to feed to his DAC of choice (which doesn't support HDCD decoding).
You're better off investigating how to rip an HDCD track.
 
Aug 30, 2008 at 9:03 AM Post #11 of 15
Quote:

Originally Posted by nd4speed /img/forum/go_quote.gif
I think in a nutshell the OP wants a hardware appliance to decode the HDCD stream to feed to his DAC of choice (which doesn't support HDCD decoding).


indeed, spot on. simply looking for input about other "hardware appliances" not mentioned above.

Quote:

Originally Posted by nd4speed /img/forum/go_quote.gif
You're better off investigating how to rip an HDCD track.


and why is that? as noted above, already have ability to rip; can process correctly in HW (Oppo w/ output via HDMI) or SW (partial HDCD decode compatibility w/ limitations) for storage or playback; as stated, purpose of this thread is soliciting info about further hardware options.
 
Aug 31, 2008 at 7:53 AM Post #12 of 15
Well, it's just that I happen to be of the opinion that the current hi-resolution format offerings (especially those requiring special hardware), are destined to disappear. Even if you were able to find this HDCD decoding appliance that could output to UNENCRYPTED digital, your efforts to obtain support and the option to buy future hardware would eventually become impossible. If you could find a way to rip all of it's little bits at least you could enjoy your music in full res w/o ever having to worry about the state of hardware.

One of the big problems with these formats as I perceive it, is ironically exactly what you are facing; this "walled-garden" approach forces consumers like yourself to buy specified hardware for decoding and playback, or at the very least, prevents ripping. IMO, DVD-A held the most promise as a high res format; especially after discovering you could rip it, but alas it appears to be too little, too late.

Quote:

Originally Posted by emmodad /img/forum/go_quote.gif
and why is that? as noted above, already have ability to rip; can process correctly in HW (Oppo w/ output via HDMI) or SW (partial HDCD decode compatibility w/ limitations) for storage or playback; as stated, purpose of this thread is soliciting info about further hardware options.


 
Aug 31, 2008 at 11:41 AM Post #13 of 15
these are all very fair comments and in essence, we are in violent agreement.

there are many HDCD-encoded releases which I enjoy very much, would like to enjoy them through better D/A output chains than, ie what is built in to say an Oppo player. But having said that, thanks to Oppo that they include HDCD capability.

the search for available hardware decoding options is simply acknowledgment that there exist at this point very few options to output decoded HDCD onward to other hardware; and (until the author of hdcd.exe is able -- if possible -- to gather enough info to implement the varying reconstruction filters) no complete software decoding.

Cary 306 is actually the cleanest option I have yet seen; I am considering purchasing one for this project due to of the attributes mentioned in initial post. It would allow decoded playback through the Cary's DAC section; through any other DAC of choice; archiving decoded HDCD; or playing simply-ripped (and tagged, and managed) 16/44.1 files from a server.

then again, a solution could well be piggybacked onto the concept of archiving stereo SACD content for server use: yes it would be great to store directly from raw DSD, but one generation of good analog is certainly not end of the world. so, investing in a high-quality ADC, or one of the emerging DSD recorders (ie Korg) with ability to downsample files to DXD or 24/192, could be part of the solution.

I am very interested to hear from anyone who is aware of other products which accept digital in, decode HDCD, and provide the decoded HDCD on digital output.

thanks!
 
Aug 31, 2008 at 3:15 PM Post #14 of 15
Quote:

Originally Posted by emmodad /img/forum/go_quote.gif
WMP also has issues and may be phasing out HDCD compatibility


What are the issues with HDCD playback in WMP?

Thanks.
 
Sep 1, 2008 at 3:28 AM Post #15 of 15
apologies, perhaps I should have started that phrase with "IIRC..."

discussion in several threads of hydrogenaudio and doom9 fora during development of hdcd.exe revealed that WMP did not upsample audio from 44.1 to 88.2 and hence most probably could not be correctly implementing the switchable reconstruction filters as defined by HDCD requirements. (Also, WMP9 apparently detected HDCD flag but peformed no decoding). Some of these threads:

HDCD in Windows Media Player [Archive] - @forums

Extract HDCD - Hydrogenaudio Forums (see esp from post 65 onward)

HDCD waveforms - Hydrogenaudio Forums

HDCD Software Decoder - Doom9's Forum (ie post 20)


these are indeed a bit dated; but have seen no update in those or other fora to explain that any newer version of WMP does the reconstruction filtering correctly.
 

Users who are viewing this thread

Back
Top