bees@drux3.UUCP (Ray Davis) (10/11/83)
Last weekend, KBCO in Boulder, CO did an all compact disk format.
While listening to one selection, it suddenly sounded as if it
were skipping! You know... as with a vinyl album... it gets
stuck and keeps repeating itself. After a minute, the DJ cut
off the song and said that he guessed we witnessed the first
skipping on a CD! My question: How is this possible!
Isn't it likely this is a mechanical problem? What part of
a CD player is mechanical? Does this signify a questionable
player? (I may call KBCO to see what CD players they were using.)
Ray Davis AT&T Information Systems Labs @ Denver (303)538-3991
{ihnp4|hogpc}!druxy!beesjphalter@ihuxb.UUCP (10/11/83)
I have heard rumors that CD's have been tested with a 1/8" strip of electricians tape on the disc with no audible effect. I tried to reproduce this with my player and got a horrible mess. The sound would "drop-out" once per revolution of the disc, making it unlistenable. The tracking system also responded by "skipping" tracks, since it apparently could not sync across this kind of damage. Question: Has anybody else out there detected this? Is this normal or are some players capable of correcting a 1/8" gap? Related Issue: To date, I have purchased only one defective CD. (Exchanged by the record store after they verified the defect, of course) This CD was scratched pretty badly in an area about the size of a dime. My player responded with "drop-outs" once per revolution. Also, another player of different manufacture did the same thing. It sounds to me like CD's are not all that immune to scratches (gross scratches, that is) and dirty discs as the magazines claim. So what's the story here, are the magizines feeding us a bunch of lies or can some players really track through large disc defects. My experience says the players can't. Anyone know?
rhf@druxx.UUCP (Ondish) (10/11/83)
KBCO uses a Denon player. The CD "skip" is possible but it is the first time I've heard of it. The scanning laser is moved much in the same way as the read head on a computer disk drive. And you know what kinds of problems people have with them, right? E. Murphy
shauns@tekcad.UUCP (Shaun Simpkins4059) (10/12/83)
If you'll read the magazines carefully, several times over the last six months
statements to the effect that CDs aren't indestructible have appeared, nay,
have been emphasized. A 1/8" blackout cannot be tracked, and noone ever said
it could. The widest test glitch on Philips' test CD is, if I'm not mistaken,
900 MICRONS, or about 1/32". This is about 5-10 words worth of music.
CDs are indestructible as far as play-induced wear is concerned, but they are
sensitive to circumferential scratches. Claims that they can be tracked with
a layer of peanut butter on top are the product of fecund minds.
There ain't no such thing as a free lunch.
--
Shaun Simpkins
uucp: {ucbvax,decvax,chico,pur-ee,cbosg,ihnss}!teklabs!tekcad!shauns
CSnet: shauns@tek
ARPAnet:shauns.tek@rand-relayjeff@tesla.UUCP (Jeff Frey) (10/14/83)
I`ve got 32 CDs so far and have never heard a skip. I have heard, since
February, perhaps two soft (i.e., nonreproducible) dropouts lasting much
much less than a second each. I handle the discs as any sane person would,
by the edges to avoid fingerprints; don`t let them sit around gathering
dust outside of their {infernal} boxes, and never dust or otherwise
treat them before playing. I`ve also got perhaps 500 analogue discs
that it almost doesn`t seem worthwhile playing any more (preener, dust bug,
dust cover, play). Out of all the discussion of CD`s so far, plus my
own experience, plus the imminent appearance of the $300-400 CD player,
two facts emerge:
1. the analogue record is dead.
2. there is nothing audible to criticize in the technology.
The only valid criticisms that can be made are of the masters. So let`s
stop wasting time on the technology and start seeing some CD software
critiques on the net!
Jeffbees@drux3.UUCP (Ray Davis) (10/15/83)
I don't have those audio magazines to read.
KBCO claims that the CD in question was free of debris and
they could find no scratch or blemish on the disc. Assuming
this is correct, what else could cause the CD skipping?
Ray Davis AT&T Information Systems Labs @ Denver (303)538-3991
{ihnp4|hogpc}!druxy!beesjsf007@trsvax.UUCP (10/21/83)
#R:drux3:-80100:trsvax:55100017:000:28 trsvax!jsf007 Oct 17 07:51:00 1983 A poorly manufactured disk!