[net.audio] LP easier to listen to at concert levels

don@umd5.UUCP (06/05/85)

> 
> I like the fact that my CDs will sound
> the same (no scratches etc) 5 years from now.
> Nor do I need to replace a stylus, belt, or whatever.
> 
> 						Tom Molnar

[]
Not true !! In 5 years your laser diode will have surpassed its useful
lifetime, and then you WILL have something to replace ...
$$$ An expen$ive laser assembly $$$

-- 
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What ?!!?     ^  No more ?!?
But it's a frontier of frontiers !!
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crandell@ut-sally.UUCP (Jim Crandell) (06/05/85)

> > Nor do I need to replace a stylus, belt, or whatever.
> > 
> 
> Not true !! In 5 years your laser diode will have surpassed its useful
> lifetime, and then you WILL have something to replace ...
> $$$ An expen$ive laser assembly $$$

Well yes, laser diodes do crap out eventually.  But the cost problem here,
if there really is one, is probably in the nature of what the CD equipment
makers force you to buy if you get replacement parts from them.  Laser
diodes per se, from the original sources (e.g., RCA) are not particularly
expensive until you get up into the 100-watt range.  Of course, the next
problem may be that RCA doesn't have one with the same dimensions as the
Quasimoto Electric Industrial Co., Ltd. model that's in your player,
and that's probably no accident.

Still, I wish you could get a high-quality cartridge for what common,
medium-power laser diodes cost.
-- 

    Jim Crandell, C. S. Dept., The University of Texas at Austin
               {ihnp4,seismo,ctvax}!ut-sally!crandell

mwm@ucbvax.ARPA (Mike (I'll be mellow when I'm dead) Meyer) (06/07/85)

In article <555@umd5.UUCP> don@umd5.UUCP writes:
>Not true !! In 5 years your laser diode will have surpassed its useful
>lifetime, and then you WILL have something to replace ...
>$$$ An expen$ive laser assembly $$$

From the June 85 Digital Audio:

	Phillips/Sony system standards call for a minimum of 5000 hours
	of playback time before failure. A phono stylus has a useful life
	of about 500 hours [This sounds low - mwm.] ... Sony estimates the
	current cost of a laser replacement to be under $100, including
	labor.

[Any errors were induced by the analog portion of the copy :-]

While 500 sounds low for the stylus life, 5000 is certainly longer than
you can get from a stylus. And the $100 price tag is a win compared to
stylus prices. And yes, I'm going to wait five years and see how things
wear out.

	<mike

man@bocar.UUCP (M Nevar) (06/07/85)

>From the June 85 Digital Audio:

>	Phillips/Sony system standards call for a minimum of 5000 hours
>	of playback time before failure. A phono stylus has a useful life
>	of about 500 hours [This sounds low - mwm.] ... Sony estimates the
>	current cost of a laser replacement to be under $100, including
>	labor.
>
>[Any errors were induced by the analog portion of the copy :-]
>
>While 500 sounds low for the stylus life, 5000 is certainly longer than
>you can get from a stylus. And the $100 price tag is a win compared to
>stylus prices. And yes, I'm going to wait five years and see how things
>wear out.


I seem to remember that the laser, when it goes bad, just stops
working.  There is no wearing out of it.  It works at 100%, one minute,
then not at all the next.  This is as opposed to a stylus which wears
out over time.  To me, the laser is better.  True, you are stuck without
a CD player for awhile, but I'll just use my PCM processor until it's
fixed.  By that time, the DAT (Digital Audio Tape) should be in mass
circulation.  Reports I have heard place it in availability in mid-1986.

							Mark Nevar

ron@brl-tgr.ARPA (Ron Natalie <ron>) (06/09/85)

> I seem to remember that the laser, when it goes bad, just stops
> working.  There is no wearing out of it.  It works at 100%, one minute,
> then not at all the next.  This is as opposed to a stylus which wears

Not so.  As those around here can attest to, it goes unreliable.  Sometimes
it will play a disk, sometimes not.  Usually, there are certain disks that
it won't play, while others it will.

-Ron

phil@amdcad.UUCP (Phil Ngai) (06/11/85)

In article <11256@brl-tgr.ARPA> ron@brl-tgr.ARPA (Ron Natalie <ron>) writes:
>
>> I seem to remember that the laser, when it goes bad, just stops
>> working.  There is no wearing out of it.  It works at 100%, one minute,
>> then not at all the next.  This is as opposed to a stylus which wears
>
>Not so.  As those around here can attest to, it goes unreliable.  Sometimes
>it will play a disk, sometimes not.  Usually, there are certain disks that
>it won't play, while others it will.

A recent issue of "The Bell Labs Technical Journal" was on the proposed
new fiber optic transatlantic cable (TAT-8) and among other things they
discussed failure modes in optical electronic devices. I don't recall exactly
which was which but I believe laser diodes degraded while photo-detectors
failed suddenly. Their goal was to have to repair the cable only three times
in twenty years.

The owner of a CD player, of course, doesn't care if it is the laser or the
photo-detector that has failed.
-- 
 A man could get elected President by promising to put
 the phone company back together.

 Phil Ngai (408) 749-5720
 UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil
 ARPA: amdcad!phil@decwrl.ARPA