Standalone HDCD decoder

Is there a standalone HDCD decoder available with SPDIF HDCD in and 24bit SPDIF out?

 

If you are asking if there is something that does only that and nothing else, no.

 

I think all the HDCD hardware decoders oversample. As I remember, the original HDCD literature (maybe even the patent) postulated 88.2 KHz 20-bit digital output. Never seen a such a beast, however. Microsoft owns all the Intellectual Property now; I think there's little chance we'll see such a device.

 

A PC with a 24 bit sound card using Windows Media Player.

 

Bad luck then.
According to these datasheets it is possible.
http://www.vt52.com/ftp/semi/pmd100.pdf
http://www.fine21.net/hdcd/Data/pmd/pmd200.pdf

 

Why don't yo just decode the CD or the files to 24-bit?

There are several converters which have HDCD detection and conversion inbuilt. dBPoweramp for example, you can just say that it should convert HDCD encoded discs to 24-bit PCM files also CUEools will do this for you.

You can then play them as 44.1/24 bit files.

-
aleg

 

I know, but they will not do it 100% perfect as it should.
The chip decoders will do it 100%.

 

I don't know what makes it 100% perfect and if PC is an option, but Foobar 2000 has recently got an HDCD plug-in.

 

Never knew the software decoders were not doing it right.
Do you have any links to read somewhat more about that?

 

Here you have it:
http://www.audioasylum.com/cgi/t.mpl?f=dvda&m=20504
http://boardreader.com/thread/HDCD_Decoder_99b8X1pab.html

 

HDCD is actually incompatible with upsampling or oversampling. I have actually done some experimenting:

1)decode HDCD to 24/44.1 with dbPoweramp
2)dither to 16/44.1 with Izotope mbit+
3)playback on CD player with oversampling DAC or using my DACMagic

there appears to be very little difference between the CD made this way played back through an oversampling DAC and the original HDCD played through an HDCD (Denon DVD2910) player.

BTW, the links provided don't really address whether or not dbPoweramp correctly decodes the HDCD processing.

 

There's something strange with dbPoweramp.
The noisefloor of a non-decoded HDCD stream only is at -138dB (approx. 23bit).
The noisefloor of a decoded HDCD stream only is at -120dB (approx. 20bit).
So isn't it better to play a HDCD non-decoded with a 24 bit dac?

 

See: http://members.quicknet.nl/arnold.van.heyst/Test.zip

 

Foobar2000 and dBpoweramp HDCD detection & decoding are based on HDCD.exe, which was created by emulating Windows Media Player. What WMP does not do (and consequently, neither does HDCD.exe) is decode the transient filter function. Although, it can detect it.

 

Not with SPDIF, but you can always get SPDIF<-->AES/EBU converters:

http://connect.euphonix.com/documents/HDCD_Model_Two_4p_0102.pdf

Not cheap, and you may as well use its DACs if you go this route!

 

??? What, how can the noise floor of a CD be -138 dBFS? This is number is highly suspicious and way too low...

 

Funny ...

Just use a bitscope and recognize that your "24 Bit" example is only 14 bit ...

There must have something gone completely wrong at the decoding.

If you want to get the best out of HDCD coded CDs, the only software whioch is available and should do it quite right is Windows Mediaplayer (maybe only older versions, ... ?), and a plugin to capture the output in 44,1/24 *.wav (search Robotron MPWAVout).

AFAIK, the mentioned filter-switching wasn't part of the decoding engine.
It was only used on encoding the material (into 16 bits). But I#m not 100% sure of this ..., and, to be honest, I don't care anymore ;-)

And to the point of -136dbfs noisefloor:
"Noisefloor (FFT derived) doen't mean "dynamic range"!
The "noisefloor" of an unditherd 16 bit signal is indeed at around 130 dbfs.

Cheers
Harald

P.S.:
There are some (multi-)players out there which are able to decode HDCD CDs, and which are transmitting the decoded (24bit) signal via HDMI.
If one uses a HDMI to S/PDIF splitter ...

 

The "noise floor" is infinitely low if you're counting "digital zero", which is also known as "muted", regardless of the bit depth. Even a 1-bit signal has an infinite noise floor by this definition, which INHO, is not correct. Usually, when one refers to the noise floor of a transmission channel, he is talking about an unmuted channel, which on a CD, would be the dither signal. HDCD must be dithered, the dither contains the HDCD control channel.

Dynamic range is the difference between the maximum allowable signal level and the noise floor. With digital audio, maximum allowable level is 0 dBFS, so if the noise floor is, for example, -90 dBFS, the dynamic range is 0 - (-90) = 90 dB. With souce noise taken into account, the noise floor is usually much higher and the dynamic range correspondingly lower.

 

I have a DAC that allows me to select (with a toggle switch) between HDCD decoding and upsampling. Can't do both simultaneously because of the incompatibility.

 

And sell my new Benchmark DAC1?
No thanks

 

Like this one:
http://www.gefen.eu/lshop,showdetai...showrub--homecinema.converter_and_scaler,.htm
and there are more.

 

A high quality, used, inexpensive DAC is what I would recommend.

I know because I have one, and will use it when I have purchased a NON hdcd decoding redbook player. (So far, I haven't needed to use it.)

The "it" is the PS Audio DL Three (not the current DL 3). Actually designed and built by the guy who left PS Audio to start Threshold.

Built like a tank. I'm not fond of the DAC's redbook performance - but that may be system/cable dependant.

HDCD, however, is just as good as my NAD players' decoding - which is to say stellar.
Absolutely wonderful.

The last unit I saw on Audiogon.com was going for $75.00 - a steal. And it has unbalanced and balanced out, SPDIF, Optical in and a detachable power cord. Heavy piece of machinery.

Pic coming...

 

Detecting and doing nothing with it?
Why?

 

Here's a pic of the PS Audio DL-Three (ca. 1997)

 

And a decoded HDCD as 24bit on the spdif?