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PROBLEM: CD Player Digital Output

A

Arfa Daily

Jan 1, 1970
0
Chronic Philharmonic said:
The sending device might be coding the datastream as a mono feed, or the
receiving device is failing to decode the datastream as a stereo feed. It
might be something as simple as a configuration problem (one of the
devices is set to 'mono'). To diagnose a fault, use a protocol analyzer,
or a process of elimination by substituting components until you get
something that works.

Even if it were, that would not result in the loss of one physical channel's
reproduction from the amp. What you would have is both left and right
channels combined into one single mono channel, which would then be
identically coded onto both left and right channels, within the single
SP/dif data stream. So you would get two channels physically reproduced, but
each containing the same mono audio.

Arfa
 
C

Chronic Philharmonic

Jan 1, 1970
0
William Sommerwerck said:
There is no such thing, in consumer products, as a mono SPDIF feed.
Indeed,
one of the design errors of the Compact Disc is the failure to include a
mono mode that would double disk capacity for pre-stereo recordings.

Right, I was thinking AES3.
feed.

Which makes no sense, as it's hard-wired to divvy up the signal into left
and right.

Right, I was thinking AES3.
 
A

Arfa Daily

Jan 1, 1970
0
Richard Crowley said:
"Arfa Daily" wrote ...

But only a fantasy academic discussion as there is no monaural mode
defined for SPDIF.

Probably true enough, but the occasional flight into academic fantasy does
no harm, and keeps the old grey cells firing ... d;~}

Arfa
 
E

EADGBE

Jan 1, 1970
0
OK, I remembered that one of my other CD players--a Magnavox CDB650--
also has a digital output.

I patched it into the Yamaha preamp and got the same results--no right
channel sound.

I also tried another cable (dumb, I know--I'm still thinking
"analog"!) and got the same results.

I also tried using another one of the preamp's digital inputs and got
the same results.

So I can safely say that the fault lies somewhere inside the preamp.

Time to get out the hammer and duct tape......
 
G

Gareth Magennis

Jan 1, 1970
0
EADGBE said:
OK, I remembered that one of my other CD players--a Magnavox CDB650--
also has a digital output.

I patched it into the Yamaha preamp and got the same results--no right
channel sound.

I also tried another cable (dumb, I know--I'm still thinking
"analog"!) and got the same results.

I also tried using another one of the preamp's digital inputs and got
the same results.

So I can safely say that the fault lies somewhere inside the preamp.

Time to get out the hammer and duct tape......



Far be it from me to say I told you so, so I won't.


Actually your original instincts were right. Digital either works or it
doesn't.



Gareth.
 
A

Arfa Daily

Jan 1, 1970
0
Don Pearce said:
Ah, you don't have a DAB radio then? The background sound of boiling mud
in low signal conditions is a joy.

d

LOL !!

Arfa
 
E

EADGBE

Jan 1, 1970
0
Far be it from me to say I told you so, so I won't.

Actually your original instincts were right.  Digital either works or it
doesn't.

Gareth.

Gareth:

Oh, I never doubted your assessment.

I just wanted to do some more testing, in the interests of thoroughly
defining the problem.

I suspect that the problem is physical (broken solder connection,
etc.) rather than electronic...at least I hope this is the case.

It will be some time before I have time to sit down and see what the
problem is, but when I do, I will let everyone know what I find.

Many, many thanks for all of the kind assistance!
 
A

Arfa Daily

Jan 1, 1970
0
Far be it from me to say I told you so, so I won't.

Actually your original instincts were right. Digital either works or it
doesn't.

Gareth.

Oh, I never doubted your assessment.

<snip>

In reality, none of us did really. We wuz jus' messin' wiv ya and adding a
bit of interesting debate to the issue ... d;~}

Arfa
 
G

Gareth Magennis

Jan 1, 1970
0
Don Pearce said:
I don't mean that, I mean this - what happens when there isn't enough
signal strength.

http://81.174.169.10/odds/baddab.mp3

d


That sounds like John Humphrys pretending to be a Dalek.
I think its slightly less annoying than FM radio on the edge of reception,
where it would sound like he was pretending to be a force 9 gale in mono.



Gareth.
 
A

Arfa Daily

Jan 1, 1970
0
Don Pearce said:
Yes, but there is an important difference - the FM signal drops into noise
gracefully and slowly. That DAB signal is only 1dB or so bigger than one
that is not received at all, and 1dB bigger again would be received
cleanly.

d

I think that when push comes to shove, a lot of the 'digital revolution',
including DAB, is about money, not any advantage to the consumer. DTTV
clearly shows this where, despite the limited bandwidth available for
transmissions, government and the regulators, continue to sell licences to
every little tinpot Tom Dick and Harry station, which then get crammed into
yet another multiplex, until there's no longer enough space left there for
everyone to get in a decent bitrate, whereupon it's discretely downed, and
stations start to get on the edge of Dalekism. Likewise, TV stations start
to have objectionable motion artifacts to the point of area blocking on some
of the worst affected ones.

That's not to say that digital transmissions *can't* be good in terms of
viewability and listenability. A 'good' full bitrate DAB transmission, or
better yet a radio or full bitrate satellite channel, can be excellent and
at least up to, if not exceeding a comparable analogue transmission of full
quality. It's just a shame that no matter how good the starting point, a
coupla dB is the difference between reception and digital cliff. Personally,
I'm with Don on that one, and I'd rather see the picture or hear the sound,
gradually deteriorate, as the signal level falls off.

So, is Freesat going to knock Freeview on the head ? I can't see any reason
why not, and can see one very good reason why it might.

HD

And that brings us back to the bandwidth issue ...

Arfa
 
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