SPDIF???

[RuffRyder1672]

What is SPDIF? It is a sound type jack on the back of my dvd drive? What is its purpose, and should I use it instead (or with) the regular sound cable?

Thanks for your time.

[Greebe]

It's a standard produced Sony/Philips for digital audio. Also known as S/PDIF, (Sony/Philips Digital InterFace. This uses a 75 ohm coax cable to connect other SPDIF compliant devices.

So if you don't have a SPDIF input on your soundcard then it's of no use.

[Bixler]

Hey Mike,

If the DVD Drive is actually sending the S/PDIF stream, could this not be routed directly to a home theatre type reciever rather than a sound card?

I've been nosing around for a compatible A/V reciever for my G200 Marvel/HW decoder/DVD setup, and had always assumed that a "Digital Input" on the back of one of these recievers would work.

Not So??

[Maggi]

The signal is a digital serial data stream that carries all the channels ...

[Greebe]

Tim, Some high end audio equipment have what is called a Toslink digital optical input(s). This is a variation on SPDIF design.

here's a schematic for a SPDIF (TTL) to Toslink optical

[Bixler]

Several of the recievers I've been looking at have a single RCA female jack labled "Digital In." This is not S/PDIF???

Most of these higher end recievers offer the option of "Optical" or "Coax."

Again, I've just assumed that the "Coax" version of this input would recieve the S/PDIF output of my Marvel G200 TV's BOB. I have the hardware decoder, and this is one of the reasons I bought it...looking to the future when I finally do buy one of these A/V recievers.

Is the S/PDIF stream different than the "Digital" stream that these inputs are labled for??

[nehalmistry]

hi, my sound card only has spdif output, what devices can i connect it to ???

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P5A-B AMD K6-266@300
Matrox Milleniumm G200 AGP (oh, lets party)
Creative SB Awe32 (a classic, superb card)
Realtek 8029A NIC Card
64meg Ram
Ali V agp chipset
ICQ UIN: 24730025

[xortam]

Same thing. Use an RCA/Coax adapter to run coax from your DVD or sound card to the Coax input of your decoder (receiver). The optical connection is equivalent to TOSLINK, which uses a fibre optic cable ... something your PC DVD doesn't have. S/PDIF is not necessary on the DVD. The digital stream is sent along the PC bus, via your device controller, to your CPU, back to the PC bus, and to the sound card (if S/PDIF equipped) for pass-through out to an external decoder (DD a.k.a. AC-3, and/or DTS).

[Greebe]

Tim, it depends on the equipment, so without additional info I can't say. Toslink & S/PDIF are based on the RS422 standard tho. Maybe this tidbit will help you in your quest for an answer.

[Bixler]

Xortam:

Marvels have a special S/PDIF output jack on the breakout box which sends an active stream if you have the Matrox Hardware DVD decoder addon.

This has been enough of a warning that I know I'll have to try before I buy.

Thanks for the info guys.

[xortam]

Bixler ... If its S/PDIF, then it supports the serial digital data stream. The only difference between the coax and optical connections on the receiver is the physical/electrical interface (Physical/MAC layer); the digital data stream is the same. That's why you see in Greebes diagram a transmitter which simply converts this electrical signal into light transmissions (no data translation).

The only thing I know about Marvels and the DVD add-on is what I read on the Matrox website. The DVD module is described as providing DD decoding so it would need to output the resultant analog signal along an RCA cable or something. The specs don't detail the connections very well. That signal would just be fed into an auxiliary analog input on your receiver. The Marvel specs look like its just delivering the normal analog a/v lines (3 RCA cables). Are you sure you've got S/PDIF connections in this mix? I don't see any details on the BOB. Perhaps your products differ from what I read on the website or the specs are just incomplete.

[MultimediaMan]

OK, for those not with the program:

The RCA "Digital In" on your Dolby Digital AC-3 home theater receiver will INTERCHANGABLY decode the 33/44/48 kHz 16 Bit S/PDIF output OR a 96 kHz 24 Bit PCM AC-3 source. It may or may not support DTS (Digital Theatre Sound - slightly better than Dolby Digital) decoding (Which the Marvel does not support to my knowledge)

There is also the somewhat esoteric AC-3RF input on some higher-end receivers, which is for Laserdisc players only. The AC-3RF source from a Laserdisc player needs to be demodulated before decoding can take place.

Hope this helps.

[SteveC]

You'll now get a load of questions asking how DTS is better than 5.1 digital surround. DTS uses a lower compression (i.e. higher bitrate), and is recorded at a higher volume, and so can sound subjectively better than dolby 5.1.

BTW: On their way is digital 7.1 which has a middle speaker to the left and the right, and also 6.1 which has a speaker for the centre of the room, and also there's a 5.2 surround which has a centre rear speaker.

The .1 in 5.1 is the sub and is only .1 because it doesn't produce all the available frequencies. The .2 in 5.2 surround is because the rear centre also doesn't produce all frequencies (i.e. a sub)

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Cheers,
Steve

"Life is what we make of it, yet most of us just fake"

[Ghydda]

Well well well, somehow RuffRyder1672 never got his answer, allthough a lot of other stuff has been mentioned.

The S/P-DIF connection on your DVD-drive is used ONLY to output the sound from an AUDIO-CD when played back from the DVD-drive. Nothing else.

The datastream can be piped into whatever S/P-DIF compatible equipment you might have. I have a portable MD and when I copy a CD to MD I always use the S/P-DIF output from my CD-ROM drive. This gives the best quality possible.

Ghydda

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2+2=5 - but only for extremly large values of 2.

[MultimediaMan]

Oops: was that the crux of the question?

If so, excuse my blathering.

I do have something useful to add to that: Not all CD/DVD drives that have the two pin digital connection present have the feature enabled.

There have also been reports of some digital outs signals not being strong enough and/or having too much jitter for some hone receivers to decode the bitstream. (For those of us whom have hacked up an external output from our CD/DVD-Roms)

I'll stop at jitter without going into THAT particular subject, for it can get heated.

Best to all.