On Wed, 3 Dec 2003 07:55:24 +0000 (UTC)
(Stewart Pinkerton) wrote:

no, actually hes right, its a one-way connection, no feedback - bits
WILL be dropped by it.

No actually he's not, since in domestic situations the noise immunity
and jitter level of the connection is sufficient to ensure that no
bits will ever be dropped - at least above a 1 in 10 million or so
level where we could actually measure it, let alone the one in ten
thousand or so where we might actually hear it!

I know that! thats why I wrote :-

I doubt anyone will actually care about the likelyhood though...

Quite so. And yes, I do know that trueGaussian noise implies that a
bit *will* be dropped at some point - but how many systems actually
contain a true Gaussian distribution?

Exactly

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

On Wed, 3 Dec 2003 03:58:18 -0500
"Arny Krueger" wrote:

no, actually hes right, its a one-way connection, no feedback - bits WILL
be dropped by it.

Not necessarily. The sink clocks itself to the source and they operate in
synchronization.

Yes necessarily. if you feed bits down a wire, sooner or later, a bit will get minced on the way down for what ever reason (try listening to a Spdif (copper) connetion in space, for example - I bet thats, er, fun ;-)

SPDIF has *no* feedback channel with which to re-request the data so its just GONE.

on *earth* with reasonable cabling, the odds of the bits getting minced are pretty minute though.

--
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Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

On Wed, 3 Dec 2003 03:58:18 -0500
"Arny Krueger" wrote:

no, actually hes right, its a one-way connection, no feedback - bits WILL
be dropped by it.

Not necessarily. The sink clocks itself to the source and they operate in
synchronization.

Yes necessarily. if you feed bits down a wire, sooner or later, a bit will get minced on the way down for what ever reason (try listening to a Spdif (copper) connetion in space, for example - I bet thats, er, fun ;-)

SPDIF has *no* feedback channel with which to re-request the data so its just GONE.

on *earth* with reasonable cabling, the odds of the bits getting minced are pretty minute though.

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

On Sat, 29 Nov 2003 23:33:24 -0000, Nath wrote:

"BWGames" wrote in message
...
Does this transmit over standard phono cable or need a special type?

Thanks...
--
BWGames
to email change de.news to de-news

Single 75Ohm coaxial cable. RCA to RCA.

any rca cable will work perfectly if your run is less than a fraction
of a wavelength (ie: less than 500')

On Sat, 29 Nov 2003 23:33:24 -0000, Nath wrote:

"BWGames" wrote in message
...
Does this transmit over standard phono cable or need a special type?

Thanks...
--
BWGames
to email change de.news to de-news

Single 75Ohm coaxial cable. RCA to RCA.

any rca cable will work perfectly if your run is less than a fraction
of a wavelength (ie: less than 500')

On Sun, 30 Nov 2003 20:48:34 GMT, Bedouin bedouin@yonderblue wrote:
"Jim Lesurf" wrote in message
...
Strictly speaking, the cable should have a 75 Ohm characteristic
impedance,
and many phono leads intended for analog interconnects won't have this
impedance. That said, provided the cable is short (metre or so) this is
unlikely to give a problem.

Strictly speaking the connectors should be 75 Ohm as well - which is a bit
of a problem since most use phono connections and there is no such thing as
a 75 Ohm phono plug.

it doesn't matter.

The connection hardly even has to be shielded.

On Sun, 30 Nov 2003 20:48:34 GMT, Bedouin bedouin@yonderblue wrote:
"Jim Lesurf" wrote in message
...
Strictly speaking, the cable should have a 75 Ohm characteristic
impedance,
and many phono leads intended for analog interconnects won't have this
impedance. That said, provided the cable is short (metre or so) this is
unlikely to give a problem.

Strictly speaking the connectors should be 75 Ohm as well - which is a bit
of a problem since most use phono connections and there is no such thing as
a 75 Ohm phono plug.

it doesn't matter.

The connection hardly even has to be shielded.

On Wed, 03 Dec 2003 08:53:02 +0000 (GMT)
Jim Lesurf wrote:

Unidirectional steady flow has the advantage of 'simplicity'

True, although (and I assume the reason why you used quotes) either solution is probably a single chip these days ;-)

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

On Wed, 03 Dec 2003 08:53:02 +0000 (GMT)
Jim Lesurf wrote:

Unidirectional steady flow has the advantage of 'simplicity'

True, although (and I assume the reason why you used quotes) either solution is probably a single chip these days ;-)

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

On Wed, 03 Dec 2003 10:30:56 +0000, Ian Bell
wrote:

Stewart Pinkerton wrote:

On Tue, 02 Dec 2003 19:36:53 +0000, Ian Bell
wrote:

Stewart Pinkerton wrote:

On Tue, 02 Dec 2003 10:40:52 +0000, Ian Bell
wrote:

Interesting but completely wrong. The SPDIF first has to be
deserialised. The data has the clock embedded in it which first has to
be recovered
before the data can be reclocked and fed into a shift register. A PLL
is used to recover clock and jitter in the SPDIF clock edges will have
little effect on this as the PLL time constant is much longer than the
jitter.

Interesting, but completely wrong....................

Any jitter which is present in the incoming datastream will be
attenuated very roughly by the ratio of the main jitter frequency
(commonly 50/100Hz from the power rails) to the PLL time constant
(commonly 10Hz or so to quickly achieve lock) . As you can see, this
isn't much in the way of attenuation! A few of the better DACs
incorporate double PLLs with a secondary loop having a time constant
of a second or so, allowing much better jitter suppression, but the
basic fact remains that jitter in the incoming datastream can only be
*reduced* by the PLL, not eliminated. For that, you require to reclock
the datastream from an independent free-running low-noise clock, and
this is *very* rare.

Rare it may be but that was precisely what i said.

No, you specifically mentioned PLLs, which do *not* reclock the data.

No, the PLL is there primarily to *recover* the enbedded clock and and i
specifically mentioned a separte clock.

No, you mentioned 'reclocked', but then mentioned nothing except PLLs.
True reclocking, as I pointed out, is mostly *not* the standard method
used in digital audio.
--

Stewart Pinkerton | Music is Art - Audio is Engineering