"chung" wrote in message
news:2DfSb.139589$5V2.729911@attbi_s53...
Steven Sullivan wrote:
Fran??ois Yves Le Gal wrote:
On 29 Jan 2004 01:20:57 GMT, chung wrote:

there is a possibility that such noise may cause problems in
amplifiers
and speakers, which result in intermodulation and other effects that
are
audible.

It's more than a possibility, particularly with improperly designed and
marginally stable "audiophile" electronics. Hence the variable low pass
filter fitted to a number of SA-CD players...

What's the highest frequency such filters allow to pass?

More importantly, what is the attenuation of such filters at 20KHz? And
if such filters are used, there goes the advantage of higher bandwidth
of SACD.


IIRC, the mildest Sony filter (and they only use them on their top of the
line machines) has a -3db point of 36khz. The others I believe are 58khz
and 76khz. Perhaps somebody with the SCD-1 machine can correct me. The
Sony filters are very mild first order filters, I believe.

Krell's machine also has filters...I don't know their design.

My own C333ES has a playing frequency range of 2hz to 100khz, with a -3db
point of 50khz, which is what I believe Sony now specs for most of their
machines.

Just for comparison, the 96/24 on my Toshiba 4700 which is the comparable
surround performance to the SACD, is 4 to 44khz stated range*, with no -3db
point published. However, a test by Sound & Vision of the later 4900
updated model shows response down -0.6db @ 42khz (for 96/24) which would
make it roughly comparable to the Sony, but with what must obviously be a
sharp filter at that point.

* I know, I know...it seems like it should be to 48khz, but 44khz is what
Toshiba quotes for 96/24. It also quotes an upper limit of 88khz for
182/24. Perhaps these are 3db points, but they are not stated as such.