Request 'Gyan' On Digital Interface Formats

Autor

Beitrag

Amp_Nut
Inventar

#1 erstellt: 06. Mrz 2008, 12:17

I am keen to know more on the Various Digital Interface Formats used for transferring Digital Data between different components of a Hi Fi System... (usually Transport To DAC)

The ones that come to mind are :

SPDIF

AES/EBU

Optical ( Glass and Toslink)

I2S

I am primarily looking for the following info :

1. An overview of the advantages / disadvantages of one vs the other . ( w.r.t. Subjective sound and / or technical)

2. Technical info on each ... Links to informative articles welcome.

3. Personal experiences in comparisions, w.r.t the sound.

Also, is I2S ever used for External ( Transport to DAC ) links ? Any example / listing of equipment that uses this format externally ?

The ( VERY Little) that I know seems to indicate that SPDIF is most prone to jitter.... yet seems to be the most widely deployed ..

Any pointers, experiences, Info & noteworthy links, most welcome.

Thanks

SNV
Stammgast

#2 erstellt: 06. Mrz 2008, 14:26

Dear Amp_Nut,

The I2S interface is generally found on USB Convertors/Dacs. This interface is supposedly the best. Although I have no personal experience.

http://www.empiricalaudio.com/frComputer_Audio.html

dCS recommends the firewire interface from their transport to the dac, as the cd is upsampled to a dsd signal only via the firewire.

Next best option is ofcourse the AES/EBU then the dig coax and the least preferred is the optical.

Regards
SNV

Amp_Nut
Inventar

#3 erstellt: 06. Mrz 2008, 17:31

Thanks, SNV.

Would love to know some more on the the AES/EBU ..

SNV
Stammgast

#4 erstellt: 07. Mrz 2008, 08:46

Whatever little bit I know :

AES/EBU - American Engineering Society/Erupean Broadcasting Union (Im sure you already know this)

Not a consumer, but a professional serial interface.
Terminated generally with XLR connectors.
Dedicated 110 ohm cable.
Carries digital audio signals only - pcm and maybe even dd 5.1
Also known as AES3. Uses shielded twisted pair cables.
Found mostly on high end gear.

Regards
SNV

Amp_Nut
Inventar

#5 erstellt: 07. Mrz 2008, 09:31

Hmmm... informative.

Many thanks

Guys... some feedback please on the practical aspects, such as popularity of one vs the other ( I guess SPDIF is the most widespread used ) and sound quality ?

sivat
Stammgast

#6 erstellt: 10. Mrz 2008, 03:29

Simple explanations.....from what i've understood

I2S - The "native" interface. Generally this signal cannot be transmitted over long cables (not even 1 feet).

Since I2S cannot be transmitted over to an external DAC, the signal is converted into SPDIF. For even better transmission (especially over long length of cables), u use AES/EBU. Again u arrive at AES/EBU from either I2S or SPDIF (depending on the design of the transport). Some folks use only a transformer to covert SPDIF into AES/EBU (impedance !!)...but i do not think it is the correct approach.

Once the SPDIF/AES-EBU arrives at the DAC, the receive chip (like the CS8414) converts the SPDIF/AES-EBU back into I2S....so that the DAC can process the signal.

Between the Receiver and DAC, the digital filters (like DF1704) are used (typically!!).

Hope that helps.

Regards
Siva.

[Beitrag von sivat am 10. Mrz 2008, 03:32 bearbeitet]

sivat
Stammgast

#7 erstellt: 10. Mrz 2008, 03:37

I use I2S between the transport module and the DAC. Both connected to each other through a 10cm wire. The DAC is placed right below the CDPRO2M.

There are lot of people who argue that SPDIF is better than I2S....and vice versa. I have not seen any convincing argument from either camp (no easy answers for you, Amp_Nut).

From my experience i will say that conversion of I2S to SPDIF or AES/EBU does not really affect the sound very much. But then again....its those very little things that finally matters

Regards
Siva.

Arj
Inventar

#8 erstellt: 10. Mrz 2008, 03:42

ok..my do paise gyan to add on to the above..

AEs/EBU aka XLR aka balanced is supposedly the superior one since being balanced can run over 30M without signal deterioration. also supposedly the best hold out against EMI. almost all high end digital equipment has this

SPDIF can have 2 possible terminations ie BNC (supposedly the more superior one) and standard RCA. PSDIF/RCA is more popular among mid fi+Hifi .

the next is Toslink..which is supposedly the worst performing but more popular in entry level and cheap dvpds..

there is an older version called the AT&T glass interface which was supposedly as good as the SPDIF, but not so popular now. only very few equipment have it these days..

these days the USB interface is catching on as well. this does direct USB to I2S conversion for use on PCs/Macs

[Beitrag von Arj am 10. Mrz 2008, 04:53 bearbeitet]

Amp_Nut
Inventar

#9 erstellt: 10. Mrz 2008, 06:42

Arj Said :

these days the USB interface is catching on as well. this does direct USB to I2S conversion for use on PCs/Macs

Interesting... can you tell me something more, or point me to a link that elaborates on the portion in bold ?

Thanks !

Amp_Nut
Inventar

#10 erstellt: 10. Mrz 2008, 06:45

Sivat said:

I use I2S between the transport module and the DAC. Both connected to each other through a 10cm wire. The DAC is placed right below the CDPRO2M.

Does the CDPRO2M output a I2S signal directly ?

Other drive mechs, do they also directly output I2S ?

Thanks for the gyan..

sivat
Stammgast

#11 erstellt: 10. Mrz 2008, 07:52

Amp_Nut schrieb:

Sivat said:

I use I2S between the transport module and the DAC. Both connected to each other through a 10cm wire. The DAC is placed right below the CDPRO2M.

Does the CDPRO2M output a I2S signal directly ?

Other drive mechs, do they also directly output I2S ?

Thanks for the gyan.. :)

Yes. CDPRO2M has both I2S and SPDIF out. It also has a inbuilt DAC...and has a very low level analgoue output (some folks i know have justed added a valve buffer using this analog output).

Most mech's should have an I2S o/p....probably not SPDIF.

Regards
Siva.