Stewart Pinkerton wrote:

Given that you can buy 24/96 sound cards for your PC which demonstrate
more than 100dB dynamic range, that wouldn't seem to be much of an
issue for 16/44 CD.


Maybe those sound cards are pretty well shielded - I don't know. I know that
the Linn Tunboks uses a conventional PCI sound card (albeit a Linn
soundcard, as conventional as that makes it), so I appreciate that a PC
which doesn't interfere with it's analogue output isn't impossible.
However, my point is that there have been no assurances from Cambridge
Audio that this is the case.

4) change the CD transport

What possible difference would that make?

No difference to the actual product as regards electrical noise, or
whatever (though if there is, that wasn't what I was getting at). My only
problem with the transport is that CA appear to be pushing the 640H as a
640C with a hard disk ('...incorporates the high-quality CD player from
the Azur 640C...' - read that as you will), when it seems that the only
similarity between the two players is (essentially) the DAC. A number of
postings on the CA forums indicated that some people did think that this
was, basically, a replacement for the 640C.

But why do you think that the 640C actually does have a different
transport mechanism from the 640H?

Bear in mind that the ten grand Meridian 800 series uses a standard 20
quid CD-ROM drive...........


The drives are cosmetically different - the drive drawer on the 640H is
deeper than that of the 640C. Given that the Azur range has a distinctive
style, to deviate from this style implies that there is some other
restriction in place, ie, it's a different drive. Besides, the 640H has a
VIA mobo installed - the drive connecting to this will be a regular
IDE-interfaced jobbie (assuming CA haven't re-written the spec for a CD-ROM
interface and got VIA to implement it), which the transport in the 640C
isn't.

I suspect that the CD-ROM drive used by Meridian may have been a bit more
than a stock £20 special. However, Meridian did also re-write the CD-ROM
controller software (although the interface remains the same) to get better
control of the spin speeds of the drive. Maybe (just maybe) this is what
Cambridge Audio have done - but there's certainly no evidence of it (and
they're not saying). So what we've got is a CD-RW drive which spins right
up to 52x - or whatever - making it useless as a regular CD player as it'd
be too noisy, and certainly not comparable with the 640C as a straight CD
player.

5) build wireless in

What, you want *more* internal noise?

Ok - I meant build wireless into the basic spec of the product; I
envisaged the aerial on the outside. Although would a transmitter in close
proximity transmitting at 2.4GHz have an effect on an audio signal?

It's a powerful RF source - who knows what intermodulations might
occur? And what's the point, in a domestic installation?

Is there a reason for not using wireless in a domestic installation?

Granted, these are criticisms of a product which is yet to be released; the
point of this post was to raise issues (both actual and potential) with the
640H (and to make a point about their removal of their forums).