Dave Plowman wrote:

You wouldn't want the average CDROM drive in a CD player. Too noisy.

Only because they're doing 48x speed or whatever, there used to be ways
of fixing them to 1x speed by sending a SCSI/ATAPI command. Though
Windows changed from feeding the analogue audio from the drive into the
sound card's CD input to reading the audio track digitally and playing
it as a wav file a long time ago.

In article , Bob Latham
wrote:
The idea of needing a live reference is utter Bunkum, you don't. I've
been to many classical concerts and a few rock ones but it doesn't help
in the slightest.

You do push that boat rather too far. :-)

If you have no clue what a violin or any other instrument sounds like, how
would you decide if what you hear from a CD is 'fidelity'? Ditto for the
sound of a broadcast from a given hall?

If you don't give a damn for what the sound in the hall was, then, yes, you
can just pick a system, etc, for a Hi-Fi (sic) which acts as music box and
plays the noises you like. But that is a music box not a High *Fidelity*
system.

By repeatedly going to venues, hearing real instruments, etc, and
comparing, over some years, you can get at least a fair idea of what sounds
at home more like what you hear in the hall.

*If* you want to feel at home that what you hear sounds like what you heard
when at the venue, then that is a big help.

*If* you don't give a damn for that and just want a music box, fair enough.
But please don't assume that applies to *everyone* else. If your concern is
*fidelity* to real acoustic music being able to get some idea of what that
sounds like would matter..


IMHO, the dac, analogue electronics and the power supply are where any
audible differences are to be found.

This takes for granted that the disc was read with complete accuracy and
reliabilty. This isn't so in *every* case. And when it isn't, you may find
one player can get details which another may have misread. This should be a
rare problem, but in the real world rare events do still occur. How much
this matters is for the individual to decide.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics https://www.st-andrews.ac.uk/~www_pa...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article
,
D.M. Procida wrote:
Jim Lesurf wrote:

all you need to do is stream the data to a DAC, and as long as you
have a buffer (cheap) that can ensure the bits arrive without timing
irregularities (also cheap), you have something that's limited only
by the quality of the DAC.

You missed out a few points.

Firstly, that means you need a DAC. If someone chooses a CD Player
that comes in the box already, so saves the user from needing another
box, with yet more PSU, metalwork, etc.

I was asking about it from the point of view of the manufacturers, or at
least, as a viable technical solution, rather than from the point of
view of the consumer. Sorry, that wasn't very clear.

Clearly, the discerning hi-fi consumer will buy whatever seems to work
for them at the right price.

But, why do the manufacturers design and build CD players the way they
do?

I'd say it was because each will have their own ideas about the 'best' way
to get good results *and* to make a saelable product. Different engineers
will take different approaches just as different users will have different
priorities and preferences - cf Bob's comments about being able to compare
with a genuine original sound. What suits him may not suit someone else.
Doesn't make either view totally invalid, just personal.


From the point of view of creating a device from available componentry,
and then perhaps putting it on the market to compete against other
high-quality CD-playing devices, it's:

* very cheap to get all the data off a CD into RAM or another buffer *

Is it? On *every* occasion? I fear people may have become so used to Audio
CD, optical drives, etc, that they've forgotten how remarkable it is that
it works at all! :-)

When I first explained to another technician I knew many years ago how CD
Players worked to read the data optically he promptly told me it was
*impossible*. Because the raw data channel resolution seemed to be too high
for the available optical spot size/wavelength. Yet it works. :-)


It's still not clear to me whether I'm missing something about how CD
audio actually works, or whether the CD player as we've known it for the
last 30+ years is an anachronism.

Have you read the orginal Philips papers? They are pretty good. Sorry if
you know all this already, but if not, the Scots Guide does cover some of
the sheer mechanical/optical precision involved. It was made to work on a
mass market level by throwing a lot of money and engineering at the
problems. Now, it seems, taken for granted. Which in one way is telling us
just how successful those engineers were! :-)

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics https://www.st-andrews.ac.uk/~www_pa...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article ,
RJH wrote:
At least with a good quality CD it does sound a bit like the real
thing - but how many people go to live concerts (I'm thinking
classical in any form, jazz, big band or MoR here) these days to know
what real instruments actually sound like?


'A bit'? In my experience of mainly rock/pop, nothing like a live
performance. Even if a domestic hifi could achieve the volume levels,
it'd take a heck of system (and room) to reproduce the bass etc and
'venue' acoustics of live music.

You'd hardly ever set out to record a live gig as heard from the audience.
The trend is to make it as close to a studio session as possible.

--
*Be more or less specific *

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

In article ,
Jim Lesurf wrote:
If you have no clue what a violin or any other instrument sounds like,
how would you decide if what you hear from a CD is 'fidelity'? Ditto for
the sound of a broadcast from a given hall?

It's one reason why well recorded male speech is a very good test of a
speaker, etc. Especially if you can have the same person speaking live.
Everyone has heard a bloke speak for real. But not that many a solo Strad
close to in an average room. ;-)

--
*A bartender is just a pharmacist with a limited inventory.

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

In article , Bob Latham
wrote:
In article , Jim Lesurf
wrote:

In article , Bob Latham
wrote:
The idea of needing a live reference is utter Bunkum, you don't.
I've been to many classical concerts and a few rock ones but it
doesn't help in the slightest.

You do push that boat rather too far. :-)

If you have no clue what a violin or any other instrument sounds like,
how would you decide if what you hear from a CD is 'fidelity'? Ditto
for the sound of a broadcast from a given hall?

It just doesn't work like that for me and never has. Some people claim
you cannot decide on kit without listening to "real" music and not
studio created stuff, I don't agree with that either.


That's fine *FOR YOU*. But not a basis for telling *everyone* else they
will be exactly the same as you.


If you don't give a damn for what the sound in the hall was, then,
yes, you can just pick a system, etc, for a Hi-Fi (sic) which acts as
music box and plays the noises you like. But that is a music box not a
High *Fidelity* system.

I just totally disagree. By that token anyone who doesn't listen to jazz
or classical is not likely to end up with High Fidelity.

You fail to distinguish cases in the relevant way. Some recordings will be
in a venue or hall or similar and the acoustic will be a part of the sound
an *audience* would expect to hear. Others will be laid down in a studio
and be 'created' by recording engineers, etc.

[snip]

I have never and will never evaluate kit on classical music, for me it
does not push the system to the edges to see what disappoints or what is
clean.

That's fine for your individual value of "I", but not a basis of asserting
it applied to *everyone* else.

*If* you want to feel at home that what you hear sounds like what you
heard when at the venue, then that is a big help.

Whatever you buy you'll never get anywhere near a live performance in a
different room and hours later you will not be able to recall anyway.

Yet from experience you can get 'nearer' by taking comparisons into
account.

Your views and requirements are fine for you, but avoid taking for granted
they all apply to *everyone* else in *every* case.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics https://www.st-andrews.ac.uk/~www_pa...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On 13/11/2017 02:22, Trevor Wilson wrote:
On 13/11/2017 12:39 AM, D.M. Procida wrote:
Now that the contents of a CD can be held in RAM, never mind in other
cheaper and still very fast digital storage, what does an expensive CD
player offer that a cheap transport and a decent digital-to-analog
converter cannot?

If DAC products can buffer seconds' or even minutes' worth of data, and
can stream it out to the actual DAC circuitry with GHz precision, there
doesn't seem to be much need any more for costly CD players.

Am I missing something?

**A CD player, unlike a computer transport, interpolates errors. It does
not re-request information be re-read. An argument can be made that a
higher quality transport (more expensive) may read disks without issuing
as many errors. Are those errors audible? Unlikely, except under extreme
circumstances. Nonetheless, high quality transports add very
significantly to the cost of a CD player.

Yes, Trevor, you are missing something.

A CD player does not normally interpolate errors. Most don't even try.
What they do is use the multi-level error correction data that comes
with the data to work out what they should have played.

Andy

On 14/11/2017 13:46, Bob Latham wrote:
Over several years I have ripped 2400 CDs. Two I couldn't rip because
they were protected and not red book standard.

Just for once Linux _is_ the answer... it sees straight through the copy
protection schemes. Microsoft played ball, and deliberately did NOT
bypass the copy protection. Since the Sony rootkit scandal things may
have changed, so it may be worth giving them another go.

Andy

On 15/11/2017 7:56 AM, Vir Campestris wrote:
On 13/11/2017 02:22, Trevor Wilson wrote:
On 13/11/2017 12:39 AM, D.M. Procida wrote:
Now that the contents of a CD can be held in RAM, never mind in other
cheaper and still very fast digital storage, what does an expensive CD
player offer that a cheap transport and a decent digital-to-analog
converter cannot?

If DAC products can buffer seconds' or even minutes' worth of data, and
can stream it out to the actual DAC circuitry with GHz precision, there
doesn't seem to be much need any more for costly CD players.

Am I missing something?

**A CD player, unlike a computer transport, interpolates errors. It
does not re-request information be re-read. An argument can be made
that a higher quality transport (more expensive) may read disks
without issuing as many errors. Are those errors audible? Unlikely,
except under extreme circumstances. Nonetheless, high quality
transports add very significantly to the cost of a CD player.

Yes, Trevor, you are missing something.

**No, I'm not missing anything.


A CD player does not normally interpolate errors. Most don't even try.
What they do is use the multi-level error correction data that comes
with the data to work out what they should have played.

**Yes, they do and if error correction schemes fail, they resort to
interpolation. Computer drives do not use interpolation.


--
Trevor Wilson
www.rageaudio.com.au

Jim Lesurf wrote:

I was asking about it from the point of view of the manufacturers, or at
least, as a viable technical solution, rather than from the point of
view of the consumer. Sorry, that wasn't very clear.

Clearly, the discerning hi-fi consumer will buy whatever seems to work
for them at the right price.

But, why do the manufacturers design and build CD players the way they
do?

I'd say it was because each will have their own ideas about the 'best' way
to get good results *and* to make a saelable product. Different engineers
will take different approaches just as different users will have different
priorities and preferences - cf Bob's comments about being able to compare
with a genuine original sound. What suits him may not suit someone else.
Doesn't make either view totally invalid, just personal.


From the point of view of creating a device from available componentry,
and then perhaps putting it on the market to compete against other
high-quality CD-playing devices, it's:

* very cheap to get all the data off a CD into RAM or another buffer *

Is it? On *every* occasion? I fear people may have become so used to Audio
CD, optical drives, etc, that they've forgotten how remarkable it is that
it works at all! :-)

It is pretty remarkable. And it is remarkable, but also galling, that my
£20 USB optical drive can reliably read anything I put in it, while the
hi-fi CD players in the house that I spent considerably more on will
reliably refuse to play certain discs (and not all the same ones in each
case).

Have you read the orginal Philips papers? They are pretty good.

I haven't, no. I confess that my ambitions for technical reading rarely
extend beyond software documentation these days.

Daniele