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-   -   Looking for tech specs to SACD's equivilant of SPDIF. (http://www.diyaudio.com/forums/digital-source/21886-looking-tech-specs-sacds-equivilant-spdif.html)

Brian Guralnick 23rd October 2003 09:27 PM

Looking for tech specs to SACD's equivilant of SPDIF.
 
I'm looking for tech specs to SACD's equivilant of SPDIF. In other words, how do they transmit the DSD disc info, or, 6 x 192KHz, 24 bit channels multiplexed on 1 coax, or optical signal.

Is there some sort of "red-book" for SACD?

OliverD 23rd October 2003 09:41 PM

As far as I know all interfaces between separate SACD transports and DACs are proprietary.

The music industry doesn't like high resolution digital copies.

Gridstop 23rd October 2003 11:22 PM

SACD can be transmitted over firewire using the IEC61883-6 standard.

I've heard that some upcoming transports & DACs will support this but no specifics.

If you are not a corporation you probably will not have access to this. It seems unlikely there will be any SACD IEC61883-6 integrated device chips.

rfbrw 23rd October 2003 11:27 PM

The Scarlet book is to SACD what the Red Book is to CD

OliverD 23rd October 2003 11:57 PM

BTW, can anyone explain to me why SACD, or more specifically the DSD format, is supposed to be superior to the CD system? Never understood why people are so mad about it. Ok, there are more channels, but...
:confused:

Even when you get the DSD out of your box, all you can do is connect some DSD DACs to it. There are not many on the market, and one or more of them is in your SACD player anyway. Some SACD players even convert to PCM before doing the D/A conversion. Kind of defeats the argument that DSD is superior to PCM, doesn't it? Modding seems the better approach here.
:bulb:

Or you can go through the hassle of getting DSD out of your box, build a receiver on the other end, convert it to PCM and connect some of the many I2S input DACs to it. That way, you have as much digital processing between the original sound event and the reproduction in your room as possible:

A/D-conversion through delta sigma converters, 6.14MHz ->
Converting to 96kHz/24 bit PCM for storage, mixing, DSP and mastering ->
Converting to DSD 2.8MHz for SACD ->
Converting back to 96kHz/24bit PCM for your DAC.
It's music that's put through these number crunchers.
:bawling:

Elso Kwak 24th October 2003 07:19 AM

SACD
 
Hi AMT-freak.
You are right aout the production process of SACD's. The ones made directly to DSD sound the best. Old PCM recordings or analog recordings immediately make a clean breast of it.
The masterclock in a SACD player like the Sony SCD-1 is even more critical than in a CD-player. I am lucky I got mines working.
To get an idea of the signals used by SACD have a look at the datasheet of the DSD1700 from www.ti.com)
;)

Holger Barske 24th October 2003 08:46 AM

AFAIK there are only two SACD products out there with seperated drive and converter units. First ist dcS Verdi (drive) / Purcell (converter) which use IEEE 1394 (Fire Wire). Second is from Accuphase (DP-100 / DC-101) and uses a proprietary format on a, if I recall it correctly, LVDS based system.

Brian Guralnick 24th October 2003 05:25 PM

Re: SACD
 
Wow, a lot to go through. My requests to Analog devices specs on the DSD port of their AD1955 have yet to be answered.

Quote:

Originally posted by AMT-freak
As far as I know all interfaces between separate SACD transports and DACs are proprietary.

The music industry doesn't like high resolution digital copies.

Considering most of the public is happy with MP3 (yuk,blech,cough) I donít think they need to worry about people pirating the extra minimal available DSD format discs. These discs are only a minor % of the available SACD format discs, which are also a minor % of normal compact discs.


Quote:

Originally posted by rfbrw
The Scarlet book is to SACD what the Red Book is to CD
Great, is there an available online copy? Do you have a link?

Quote:

Originally posted by Elso Kwak
Hi AMT-freak.
You are right about the production process of SACD's. The ones made directly to DSD sound the best.
;)

I believe that DSD is not a 192KHz 24bit data/channel, it's the raw pulsing from the comparator in the AD converter running at 2.xxx Mhz. This is then fed to the dac running at the same rate. I guess, in theory, you can sample and recreate over 500Khz bandwidth signals with these recordings, as per the DSD bandwidth charts within the AD1955 documentation.


Quote:

Originally posted by HBarske
AFAIK there are only two SACD products out there with seperated drive and converter units. First ist dcS Verdi (drive) / Purcell (converter) which use IEEE 1394 (Fire Wire). Second is from Accuphase (DP-100 / DC-101) and uses a proprietary format on a, if I recall it correctly, LVDS based system.
This is pretty sad. I believe that the day compact discs were released to the consumer market, the SPDIF format was already standardized.

OliverD 24th October 2003 06:01 PM

Quote:

Originally posted by Brian Guralnick
Considering most of the public is happy with MP3 (yuk,blech,cough) I donít think they need to worry about people pirating the extra minimal available DSD format discs.
Yep, but I know of no DVD-Audio capable player which would output more than 44.1KHz/16bit/stereo digitally via S/PDIF. There are some that output a 96kHz/24bit/stereo data stream or multi-channel formats, but only when playing back DVD-Video. So you have no possibility of making high resolution digital copies of DVD-A without tampering the I2S lines in the player.

My point was that the same is true for SACD players. No standard output for high resolution digital audio. And I think the only reason is avoiding high res copies.

Quote:

...I believe that DSD is not a 192KHz 24bit data/channel, it's the raw pulsing from the comparator in the AD converter running at 2.xxx Mhz...
True. I think you were misunderstood from your first post. Converting DSD to PCM is a lossy operation.

Quote:

...I guess, in theory, you can sample and recreate over 500Khz bandwidth signals with these recordings...
In theory, yes. But, unlike PCM, the dynamic range of DSD is dependent on the frequency of your signal. The higher the frequency, the worser the dynamic range and the closer the noise floor. CD beats SACD from about 5kHz upwards in that respect! Compare this to the constant 144dB dynamic range of DVD-Audio. High resolution in the human hearing frequency range is much more important than reproducing frequencies of up to 500kHz (with -20dB noise floor).

Brian Guralnick 24th October 2003 06:28 PM

Quote:

Originally posted by AMT-freak

In theory, yes. But, unlike PCM, the dynamic range of DSD is dependent on the frequency of your signal. The higher the frequency, the worser the dynamic range and the closer the noise floor. CD beats SACD from about 5kHz upwards in that respect! Compare this to the constant 144dB dynamic range of DVD-Audio. High resolution in the human hearing frequency range is much more important than reproducing frequencies of up to 500kHz (with -20dB noise floor).

I know the human ear alone can't handle these high frequencies, but, the phase of these high frequency signals, above 5Khz, on a 2 channel system defines far superior imagery with instruments like cymbals & even helps reproduce far more accurate lower frequency complex rattle noises, like the springs underneath a snare drum.

This DSD format reminds me of the great audio potential of my old Sony SLV-757UC VHS Hi-Fi's audio. Though it's 1.8 & 1.2 MHz FM, 500Khz bandwidth for the sound. Even on EP, I've measured a good flat response from 5hz to over 30Khz for full amplitude signals, for half amplitude, over 50Khz, for 1/8th amplitude, over 80Khz.


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