In article , Roger McDodger wrote:
To the original poster - if you're going to upgrade your Arcam, don't
mess about.. get one with a RingDAC processor. This is technology
licensed from dCS and is *truly* about as good as it gets. In
ascending order of value, the models are CD9, CD92, CD92T and FMJ CD23
- and they're all discontinued. Expect to pay from about £300 for the
CD9, to £500 for the CD23.

The dCS RingDAC was a good step forward. If I understand the technical
papers on it correctly, is a particular implementation of "Dynamic Element
Matching" (DEM). Its success is due to the DEM technique spreading uneven
output level errors much more evenly through the DAC's dynamic range.

However, if you look at the specsheets for the Wolfson single-chip DACs
used in Arcam kit from the CD82T onwards you will see that they too
use DEM, and it appears to be used in the same way as the dCS RingDAC
(but in a much less expensive implementation).

There are detailed differences such as the greater number of bits in
the core of the Wolfson DACs around which the noise shaping is operated,
so there are no guarantees of complete identicality. Nevertheless the
dynamic range of all good recent DACs (e.g. Crystal's line as well as
Wolfson's) has been significantly improved by using DEM.

So it is no longer clear (to me) from a technical point of view whether
the older Arcams are better than the newer ones but maybe it's up to
the OP's ears to decide.

BTW, a year ago I auditioned Arcam 72T and 93T in the same session and
small differences were there but not prominent (to me). Players like
the Sugden CD21 and the then brand new Cyrus CD8 were noticeabley
different: the top end seemed "glazed" and over-prominent. So I think
small differences do remain - probably in the filtering arrangements
rather than the DAC itself.

I decided "no" to the Sugden after moments of listening and "no" to
the CD8 after a much longer comparison with a Meridian 507. I preferred
the Meridian 507 and the Quad 99CD-P, as they were very similar or maybe
slightly better sounding than the Arcams but better packaged for my needs.
I finally bought the Quad - it tracked my "decayed" test CD better than
everything else.

--
John Phillips