Optical audio connections
 

"Phil Allison" wrote in message
...


** Stereo circuits that give near perfect audio quality would be.

That claim was in the context you just snipped out of sight - arsehole.

You'll have to point out the bit where Tony said that these circuits were
routed underground.


** Funny how phone circuits so often hum, buzz, hiss, crackle and sound
like absolute crap.

Because phone wires are not always in as good condition as they might be.
The overhead cable that carries my phone line must be 40 years old if it's a
day. There are numerous connection boxes along the way, not all of which are
well-sealed against the weather. So yes, it does buzz and crackle sometimes,
when the atmosphere is particularly moist and water gets into the connection
boxes. But when it's dry it's quiet even though for most of the route it
shares it's poles with power lines.


** Funny how domestic hi-fi audio uses co-axial type cables exclusively
and with great success then.

Yeah, because it's *cheap*. It works well enough connecting a few items
together which are physically close. But using unbalanced co-ax to connect
two systems in separate rooms is a different story, especially if both
systems have their own safety grounds. In those circumstances balanced
interconnects are the only satisfactory solution. Anyway, I thought you said
that *pro* audio was your field?

It's clear that you have no idea what you are doing or talking about.

Would I continue to get asked to install systems if I didn't?

****wit.

I really don't know why I bother with a foul-mouthed, ill-tempered imbecile
who thinks that swearing and using gratuitous insults somehow advances his
arguments. So you are going back into my kill-file.

David.

Optical audio connections
 

"tony sayer" wrote in message
...


A few years ago for an RSL broadcast the local cable company supplied us
with a few stereo circuits over 3 miles of normal copper phone cable and
apart from a slight HF loss .. no hum or other disturbance AT ALL!.


As far back as 1950 they were using ordinary telephone pairs to carry
television from OBs over that sort of distance (to get it as far as the
local telephone exchange, from where it could be connected to a wideband
circuit). The main problem was the loss of HF, so the terminal equipment
included an elaborate equaliser which had to be adjusted for each use as
telephone cables varied so much in their performance in the MHz region.
Microphony in the differential input amplifier was also a problem despite
using specially selected valves and the heaters were supplied with
stabilised DC, not a trivial thing in those days.

David.

Optical audio connections
 

"David Tosser the ****wit"


** Stereo circuits that give near perfect audio quality would be.

That claim was in the context you just snipped out of sight - arsehole.

You'll have to point out the bit where Tony said that these circuits were
routed underground.

** I made no such claim - you posturing smartarse.


The context you snipped here needs to go back:

I've used unscreened twisted pair to carry line-level audio in domestic
premises as well as cinemas. There are *far* fewer problems with
interference from such sources as there is when attempting to use
unbalanced co-ax.


** Funny how domestic hi-fi audio uses co-axial type cables exclusively and
with great success then.

It's clear that you have no idea what you are doing or talking about.


Yeah, because it's *cheap*.


** It does not work so very well because it is " cheap "

- you ridiculous, posturing smartarse prick.


It works well enough connecting a few items
together which are physically close. But using unbalanced co-ax to connect
two systems in separate rooms is a different story,

** No so - it works justs as well over hundreds of feet, with low
capacitance cable.


especially if both
systems have their own safety grounds. In those circumstances balanced
interconnects are the only satisfactory solution.


** Other, much simpler solutions exist for that issue - you know nothing
bull****ter.

Plus there is never any need to STOOP to using cheap and nasty cat 5 data
cable.

It's extremely clear that you have ZERO idea what you are doing or talking
about.


I really don't know why I bother with a foul-mouthed, ill-tempered
imbecile
who thinks that swearing and using gratuitous insults somehow advances his
arguments.


** You are a bull-****ting, lying arsehole - incapable of making sense.

So you are also incapable of coming up with a valid argument on any topic.

Cretins who dribble runny crap like you have over stinking cat 5 are all
****ing cable installers.

Congenital anencephalics the lot.

You are one of them too.




..... Phil

Optical audio connections
 

In article ,
Phil Allison wrote:
What makes you think all phone lines are run underground?.


** Stereo circuits that give near perfect audio quality would be.

FFS. Most are fibre optics these days. Older ones co-ax carrying
multiplexed digital. I doubt you'd find many analogue twisted pair music
circuits in use now.

--
*If we weren't meant to eat animals, why are they made of meat?

Dave Plowman London SW
To e-mail, change noise into sound.

Optical audio connections
 

"Dave Plowman (****ing Nut Case Dunny Cleaner )

What makes you think all phone lines are run underground?.

** Stereo circuits that give near perfect audio quality would be.

FFS. Most are fibre optics these days. Older ones co-ax carrying
multiplexed digital. I doubt you'd find many analogue twisted pair music
circuits in use now.


** Then go Sayer that one

you CONTEXT SHIFTING, ****ING ARSEWIPE !!!






....... Phil

Optical audio connections
 

In article , tony sayer

wrote:
In article , Phil Allison
scribeth thus

Due to its symmetry.


symmetry ??..


** Cannot be explained without diagrams and math.


FWIW I assumed the "symmetry" PA was referring to is the physical symmetry
that co-ax has as a coaxial circular arrangement.

This means that the internal (fundamental) TEM(00) mode conveyed has it
E-field vectors radially symmetric about the center of the cable, and
circumferential H-field vectors also symmetric (rotational symmetry about
axis of cable). To 1st order this would tend to reject external fields as
their effect tends to cancel on when you sum the coupling to the TEM mode
inside the waveguide (co-ax). However this makes assumptions about the
coupling field as well as the ideal symmetry of the cable. So field
profiles not uniform across the guide space would not be perfectly rejected
in general by symmetry.

No need for any 'math' to follow the above, although you might need some to
work out the coupling co-efficient to/from any given perturbation field
profiles. If puzzled, a diagram might help, though. :-)

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Optical audio connections
 

"Dave Plowman (News)" wrote in message
...
In article ,
Phil Allison wrote:
What makes you think all phone lines are run underground?.


** Stereo circuits that give near perfect audio quality would be.

FFS. Most are fibre optics these days. Older ones co-ax carrying
multiplexed digital. I doubt you'd find many analogue twisted pair music
circuits in use now.


Apart from the "local loop" the entire telephone network is digital and has
been for some years now. Broadcasters had to weaned off analogue music
circuits as the line plant simply didn't exist any more. (of course there is
still a good deal of copper in use, but these days it carries digital,
rather than analogue).

David.

Optical audio connections
 

Phil Allison wrote something or other as a reply to "Arny Krueger"
in a thread in which a bunch of big girls blouses have done themselves
no favours:

Are there advantages to be gained in using optical vice
coax?
Absence of grounding problems,

** The OP thinks optical = analogue.

You must learn to read all of a thread for CONTEXT before butting in.


Proper parts for interfacing quality audio over CAT-5 are readily
available.


** Are they ? Bet they are not cheap.

Hardly economic for short runs around a house.

Silly to risk RF and impulse noise injection when shielded cable is readily
available.

Even shielded cat 5.



So-called audio baluns for running audio over structured wiring exploit
the benefits of balanced audio signals.


** Arny always loves to ALLUDE to his store of secret knowledge.

It allows him to PONTIFICATE endlessly and nauseatingly.

But if you ever get to see his " store " - you'll find the cupboard is
bare.




...... Phil


Yeah Yeah Yeah, there is a whole google archive of Arny's obnoxious
pomposity, but he was slapped down so many times he has taken the hint
and calmed down in recent times. But you Phil Allison have taken insane
****** usenet ranting to a new level of lunacy, it must be an Australian
trait, - grown adults losing all control online in usenet groups.
So you don't expect any future employment or work thrown your way ever
again, you do know a quick search on your name reveals not only are you
demented and evil, but you are short and overweight too! Your family
proud of you are they, your neighbours brag that they live in same
street as you do they? What an unemployable ****** you are.

Optical audio connections
 

In article , Phil Allison
scribeth thus

"Dave Plowman (****ing Nut Case Dunny Cleaner )

What makes you think all phone lines are run underground?.

** Stereo circuits that give near perfect audio quality would be.

FFS. Most are fibre optics these days. Older ones co-ax carrying
multiplexed digital. I doubt you'd find many analogue twisted pair music
circuits in use now.


In cities they use fibre but out in other parts of the country BT
aren't going to run fibre where copper exists and will suffice!..


** Then go Sayer that one

you CONTEXT SHIFTING, ****ING ARSEWIPE !!!

Speak for yourself Bluey:!..

--
Tony Sayer

Optical audio connections
 

****wit.

I really don't know why I bother with a foul-mouthed, ill-tempered imbecile
who thinks that swearing and using gratuitous insults somehow advances his
arguments. So you are going back into my kill-file.

David.



We get quite a few intelligent Aussies here in Cambridge, it being a
University city and they do mutter about some of their brethren out in
the wilder parts of Oz .. and from what they say he seems quite polite
on the scale of things;-!....


--
Tony Sayer