jm@tekadg.UUCP (Jeff Mizener) (11/19/84)
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Two friends of mine have purchased tiny Sony CD Players. They cost
a mere $300 here in Portland, and seem to be readily available.
I am not one to be easily overwhelmed by technological innovations
(being a technological innovator in a technologically innovative company
and all), but let me say that the Space Shuttle positively Pales In Comparison
to this tiny techno-wonder from Sony. I'll be damned. The thing
just got lost on top of my stereo last night. It looks cheap. Sounds Great.
Plays Upside Down. Not really resistant to vibration, but jeez,
whatthehelldoyawant?
Before I go off the deep end here, let me say that all of my previous
reservations about the CD standard still apply. It ain't perfect. But
it's pretty good, and for $300 NOW, it's a steal. I mean it's a steal
just to OWN that kind of sophistication for only $300. But I digress.
One of the interesting things about this little guy is that Sony seems
to be saying "Hey, it's no big deal. We just crammed all this stuff in here
one afternoon to see if it'd work. LSI Digital Signal Processing? No
Problem. We do that in our sleep here." It looks about the same
level of sophistication as an early walkperson. It allows you to
go fast-foreward (semi-muted) and skip to the next track. It will
tell you playing time of the disk and time remaining on the current
track. What other possible functions could you need?
Anyway, I'm not a CD true believer, and I'm impressed. You got to remember,
if it costs $300 to buy at Stereo-Stupid-Stores, then it costs $150
wholesale. It it costs $150 wholesale, then it can't cost more than $75
to manufacture. The Japanese Did It Again.
On Other Topics:
1) Ron Natalie says that oversampling and interpolation is done by repeating
the a single sample four times and then averaging. Close, but no Banana.
The method is to insert 3 zeros between each sample so that the data
rate is multiplied by four. This stream is then run thru a digital lowpass
filter to interpolate. After the D/A it is lowpassed by an analog filter.
The reason this is done is to loosen the requirements on the analog filter.
If the
sampling rate is 176.4khz (4 x 44.1khz), then the filter has a longer
transition band to roll off over (0dB at 20khz, -80db by 22.05khz for
the un-oversampled system versus 88.2khz for the oversampled system.)
2) Someone recently said on the net that he was sorry (I think) that people
were buying all this CD stuff that was going to be obsolete in 2 years.
It would be obsolete, he said, when the new standard came out that had
more bits and higher sampling rate. Well, I'd be willing to put money
on the fact that this guy is wrong. This is The Standard. There
won't be another with more bits and higher sampling rates along anytime
soon. It took a LOT of kicking and screaming to get the recording industry
to fall for this standard. They had to be convinced, neigh guaranteed
that the standard would not change in the forseeable future. So There.
Yours for Cost Effective Audio Enjoyment,
Jeff Mizener / Tektronix Portables ADG / Beaverton OR
{ucbvax,decvax,purdue,uw-beaver,hplabs,allegra,ihnp4,ogcvax}!tektronix!tekadg!jm
ARPA: tekadg!jm.tek@udel-relay CSnet: tekadg!jm@tekherbie@watdcsu.UUCP (Herb Chong, Computing Services) (11/21/84)
The consumer standard may be fixed, but I am of the opinion, and some
other netters also, that a different and better professional standard
should be established. Building a few conversion boxes for major record
producers to go "down to" the consumer standard isn't a problem. Many
people are not convinced of the need for such a thing. See some of the
discussions in the last month or so on digital audio. This is a very hot
topic among audiophiles, bordering upon religion, but then highend
audio has always been that way.
Herb Chong...
I'm user-friendly -- I don't byte, I nybble....
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