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

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