Q: How long can I run a digital line?
 

"TCS" wrote in message

On Fri, 6 Feb 2004 13:06:49 +0000 (UTC), Jay wrote:
hello.

I'd like to run a digital out from my DVD player to a DAC. How long
can this cable be? I can use a coaxial or an optical. I was hoping
it could run six metres.

No problem. I've run 30' feet using rg58 with perfect results.

Ironically, that's the wrong impedance stuff. RG59 is the *proper* stuff for
digital audio. I don't doubt that the 58 worked fine at that length.

Q: How long can I run a digital line?
 

"Nutter" wrote in message

On Fri, 6 Feb 2004 13:06:49 +0000 (UTC), Jay wrote:

hello.

I'd like to run a digital out from my DVD player to a DAC. How long
can this cable be? I can use a coaxial or an optical. I was hoping
it could run six metres.

Is this way out or is this possible?

Thanks

J
First off, use Coax.
Second, any old piece of crap phono leed will do. As for length I'm
guessing 6m will not be a problem as the signal is digital. If you can
hear a sound with no skips or breaks, then the cable is working
perfectly.

Obviously, someone never had an audio system complex enough to have a ground
loop.

Q: How long can I run a digital line?
 

Laurence Payne wrote:

Practically-speaking, short lengths of damp string often work.
Longer lengths need the right cable. Why would YOU say this was?

I don't profess to be an expert, but...

Summink to do with reflections and/or attenuation when the characteristic
impedance of the transmission line doesn't match the impedances of the
devices being connected.

I would imagine that long lengths of "any old piece of crap phono leed"
might be poor for digital transmission since they are often used in LF
analogue applications where the input impedance is several K ohms - the
inductance and capacitance of the cable can afford to be higher.

The characteristic impedance of damp string is highly dependent on things
like the salinity of the water used to dampen the string, as well as
environmental factors, such as the rates of evaporation and replenishment.
I'd imagine that it would also require a fairly elaborate arrangment if
screening is required to minimise interference.


--
Wally
www.artbywally.com
www.wally.myby.co.uk/music

Q: How long can I run a digital line?
 

On Sat, 7 Feb 2004 22:34:13 -0500, "Arny Krueger"
wrote:

"Nutter" wrote in message

On Fri, 6 Feb 2004 13:06:49 +0000 (UTC), Jay wrote:

hello.

I'd like to run a digital out from my DVD player to a DAC. How long
can this cable be? I can use a coaxial or an optical. I was hoping
it could run six metres.

Is this way out or is this possible?

Thanks

J
First off, use Coax.
Second, any old piece of crap phono leed will do. As for length I'm
guessing 6m will not be a problem as the signal is digital. If you can
hear a sound with no skips or breaks, then the cable is working
perfectly.

Obviously, someone never had an audio system complex enough to have a ground
loop.


No, its just that I wrap all my cables with cooking foil, with ferris
(?) rings every 5cm. Each separate is encassed in steel, and has its
own feed direct to my main electrical box with a power purifer and
surge protector.

;8 )

Q: How long can I run a digital line?
 

On Sat, 7 Feb 2004 16:57:36 -0000, "Wally"
wrote:

Chris Morriss wrote:

True, I hadn't looked far enough back up the thread.

It was quoted in the post you replied to, as was the idiot's claim that
any-old-crap phono lead would do "For any length!". As soon as I read the
thick **** saying that, I immediately thought of a 100m drum of the stuff.
Then I remembered that BT used to have repeaters in their early PCM systems
and found myself wondering why. Then I realised that he was spouting total
****e.


Please please stop twisting multiple threads of mine to suit your own
needs.

First, any old crap phono lead will do for a digital signal, if you
bothered to read my post incontext you will note I was refering to the
free ones that come with all 'hi-fi' seperates.

Second, as for length, let use our brains here. When I said any length
I meant, any length that you might reasonable need for a home cinema
setup. We are talking 10's of meters here, not 100's. Next time I'll
be more precise.

Third (for Ian this one), it is cheaper to make your own leeds,
suitable cheap cable will set you back 20p p/meter, with plastic phono
plus cost 20p each.By my calcs thats £1.40 for 5m.

Summary (So as not to lose the point of this whole thread): The point
being the original poster asked what he should use and the answer is
Coax NOT Optical because the Coax route (if you follow my advice about
using free phono leeds that come with all hi-fi seperates) IS cheaper
than any Optical cable on the market. I challenge you to rebute this
statement with 'he's sputing total ****e'.

Ray.

Q: How long can I run a digital line?
 

Nutter wrote:

Please please stop twisting multiple threads of mine to suit your own
needs.

What are you talking about?


First, any old crap phono lead will do for a digital signal, if you
bothered to read my post incontext you will note I was refering to the
free ones that come with all 'hi-fi' seperates.

Second, as for length, let use our brains here. When I said any length
I meant, any length that you might reasonable need for a home cinema
setup. We are talking 10's of meters here, not 100's. Next time I'll
be more precise.

"Any" means "any", it doesn't mean a form of "any" qualified by some
unstated criteria. If you can manage something more precise than "any crap
of any length will work", that would be most welcome. If you can't manage
anything more precise, then expect to be called an idiot.


Third (for Ian this one), it is cheaper to make your own leeds,
suitable cheap cable will set you back 20p p/meter, with plastic phono
plus cost 20p each.By my calcs thats £1.40 for 5m.

Who gives a **** about that? There are people on this planet who aren't
interested in soldering up cables, or who lack the skills, the dexterity,
the tools, the time to acquire the bits and/or learn. There are people who
earn far more per hour than the money they'd save in the time it would take
to make a cable. Just because you happen to think making up a cable is the
way to do it, it doesn't follow that that's the right way for someone else
to do it.


Summary (So as not to lose the point of this whole thread): The point
being the original poster asked what he should use and the answer is
Coax NOT Optical because the Coax route (if you follow my advice about
using free phono leeds that come with all hi-fi seperates) IS cheaper
than any Optical cable on the market. I challenge you to rebute this
statement with 'he's sputing total ****e'.

Read the original post, dickhead. He asked how long the cable can be, not
what the cheapest method was.


--
Wally
www.artbywally.com
www.wally.myby.co.uk/music

Q: How long can I run a digital line?
 

On Sun, 08 Feb 2004 16:01:12 +0000
Nutter wrote:


Third (for Ian this one), it is cheaper to make your own leeds,
suitable cheap cable will set you back 20p p/meter, with plastic phono
plus cost 20p each.By my calcs thats £1.40 for 5m.

Prove it - you stated you could make a 3m lead for a quid from Maplins.
you're backtracking.

(and I know how much leads cost to make - I've made my own before now.
commercial ones cost about the same and theres no hassle.)

--
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.

Q: How long can I run a digital line?
 

On Sun, 08 Feb 2004 16:01:12 +0000
Nutter wrote:

The point
being the original poster asked what he should use and the answer is
Coax NOT Optical because the Coax route (if you follow my advice about
using free phono leeds that come with all hi-fi seperates) IS cheaper
than any Optical cable on the market.

Thats NOT *the* answer, its *AN* answer.

Another is to use optical because it eliminates another possibility for
introducing noise into the amplification chain.

Your argument about coax being free because everyone has it is invalid
not only because NOT everyone has it, but also because some equipment
comes with free optical leads in the 1/2 meter sort of range.

--
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.

Q: How long can I run a digital line?
 

Ian Molton wrote:

The point
being the original poster asked what he should use and the answer is
Coax NOT Optical because the Coax route (if you follow my advice
about using free phono leeds that come with all hi-fi seperates) IS
cheaper than any Optical cable on the market.

Thats NOT *the* answer, its *AN* answer.

Exactly. He answered a question that wasn't asked and is now whining like a
bairn as he tries to puke his dumb error back up after it was shoved down
his throat. ;-)


--
Wally
www.artbywally.com
www.wally.myby.co.uk/music

Q: How long can I run a digital line?
 

In article , Laurence Payne
wrote:


What a load of ****. Do you know what an "ohm" is?

I suspect you think it's a simple measurement of resistance. Not so,
with cables carrying high-frequency signals.

Erm, we may need to make a distinction here to avoid confusion.

The Ohm is the unit of resistance. Nominally comes from the definitions of
the Volt and the Ampere. You can then generalise by allowing the value to
be complex instead of real and specify values that way.

A cable that genuinely has a characteristic impedance of 'X Ohms' will - if
either 'very long' or attached to a load of the same resistance - act just
like a resistive load to the source. Thus if you had ten light years of 75
Ohm cable and fired signals into it, so far as the signal source would be
concerned it would (for 20 years, anyway!) look indistinguishable from a 75
Ohm resistor. Ditto for a shorter lead terminated in the matching
resistance.

However most cables that are called 'X Ohms' tend not to actually have this
value of impedance (resistance) at all frequencies, and hence may have an
impedance which is not always resistive, and varies with frequency. For
domestic digital links this matters very little, though. :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html