Re: Digital audio coax - maximum length

["mark_harrison_uk2" <mph@xxxxxxx>]

--- In ukha_d@xxxxxxx, "Kevin Hawkins" <lists@u...> wrote:
> I have some digital (audio) coax switching (Nirvis DXS) in my=20
> house and I have runs of over 50m in total length - so I don't=20
> think you will have a problem - I originally wanted to use=20
> optical but went this way because the cables were easy to make=20
> and the consensus was optical might not go the distance. I
>  understand that 'jitter' can become an issue and I did try some
> jitter compensation but tbh I couldn't tell the difference=20
> although the kit in use is probably of insufficient quality to=20
> reveal this.

Oh yes :-)

Seriously, though. Digital signals tend to be less affected than=20
analogue ones by cables, and there's a lot of rubbish put out by the=20
high-end cable manufacturers.

Mr. Harris once conducted an interesting experiment by implying to=20
Mary and I that the cable he was lending us had a four-figure price=20
tag, and that we should try it for a couple of weeks. When, a couple=20
of weeks later, I admitted that I couldn't tell the difference=20
between it and an el-cheapo =A315 cable, he smiled and said that it=20
_was_ an el-cheapo =A315 cable, and he'd been seeing if I would be=20
taken in by his sales patter :-)

Jitter is an issue, but actually, coax (SP/DIF) is so much better=20
than optical (TOSLINK) anyway that adding 50m of cable won't be=20
hideous. Jitter is far more a chipset and connection boundary problem=20
than a cable problem.

As you say, it all depends on the quality of the kit in question, and=20
how much you care (want to spend).=20

I _do_ use a jitter corrector, and it made a noticable difference in=20
my setup.

The good thing about them is that they're sufficiently specialised=20
that people who DO stock them tend to be BADA members, and BADA=20
members are used to people taking stuff, seeing if it makes a=20
difference in their setup, and bringing it back the following week=20
for a refund if it doesn't (it's part of the BADA charter.)

Of course, if you TELL your local hifi dealer that this is the plan,=20
it's a bit more polite. What's a reasonable plan in these=20
circumstances is to pay for the item, but borrow their demonstrator=20
for a week. If you decide you want it, they'll swap it for a new=20
boxed one. If you decide you don't, they haven't lost money on the=20
deal by turning a new boxed item into a second-hand one.

Regards,

Mark