variable quality cd's

[pde2000]

https://www.stereophile.com/features/827/index.html

My oldest cd player really struggles with some discs but sounds sublime when it can.  The last track will skip if it's a long recording as if the linear tracking mechanism has run out of track.  The worst discs will not even be recognised, and many will distort (uncorrected error once per revolution), especially on the first few tracks.   The newest player will play anything up to a limit (scratches and dirt).

There are now two categories in my collection; ones for the old dcd1500, and the others.  It's probably an age thing.  Looking for an explanation resulted in the above link.

[paulfromcamden]

Very interesting - thanks for the link, after a quick scan I'm going to read properly this evening.

I encountered what I think is my first off-centre CD last week - the silvered part is off-centre by a mm or so exactly like a mis-pressed LP. It plays fine but I can hear the CD mech constantly run back and forth trying to track properly.

[flood2]

https://www.stereophile.com/features/827/index.html

My oldest cd player really struggles with some discs but sounds sublime when it can.  The last track will skip if it's a long recording as if the linear tracking mechanism has run out of track.  The worst discs will not even be recognised, and many will distort (uncorrected error once per revolution), especially on the first few tracks.   The newest player will play anything up to a limit (scratches and dirt).

There are now two categories in my collection; ones for the old dcd1500, and the others.  It's probably an age thing.  Looking for an explanation resulted in the above link.

The laser needs replacing - the laser power is probably below the minimum threshold for a reliable signal. The disc is read from the inside to the outside and wobbles are common at the outer edge.  If the laser power is weak, the positioning and focus servo performance will be affected thus increasing the error rate.

[pde2000]

That's unfortunate Anthony; no replacements available.  Still it's interesting to find that many discs play perfectly and sound so good on the old machine.  I also have a dcd 1500II that is less fussy and sounds pretty good.  Before that I had another dcd 1500II that wore out, just plain stopped reading discs completely.

[Marek]

The laser needs replacing - the laser power is probably below the minimum threshold for a reliable signal. The disc is read from the inside to the outside and wobbles are common at the outer edge.  If the laser power is weak, the positioning and focus servo performance will be affected thus increasing the error rate.

This is exactly the same what I would like to mention. I had the same with my Denon (20 years old) DCD-735. Some CDs were ignored some played some with laser jumping across paths. Replacement helped for some years now I see more often the same specially when CDs are a bit dusty. Currently CD cleaning is a good solution. Strange is that 1500 is much much younger design than my 735. SO laser has to be available somewhere eg here if still valid  https://www.ebay.pl/itm/170854283494?mkevt=1&mkcid=1&mkrid=4908-226936-19255-0&campid=5338391704&customid=170854283494_293&toolid=11000 ouups sorry this is for AE version not for pure 1500

[timelog]

Usually when laser problem (laser dying):

   - track list not found at all
   - first tracks not played/jumps usually next track to try it
   - random jumps at first tracks/inner "grooves" (..disc inner tracks are firsts and last outer)
   - starts to read same short track part over and over again..can't go ahead if not externally controlled.
   - random jumps with any dependence disc used.

   - problems in dics are  rare ..try in another player.

In later CD players adjusting is made by internal automation..older versions have some adjusting points on printed circuit.

When trying to find new player, test it with worst condition dics that you have and self burned CD and CD-RW discs ...that expose quality of player/laser.

[flood2]

The "enemy" of the laser mechanism is temperature - apart from heavy continuous usage and temperature buildup in the case, impurities etc in the laser diode result in increased temperature buildup which accelerates ageing. The issue with impurities became more pronounced once the laser became a commodity item in cheap CD-ROM drives and portables - this is why CD writer drives would fail just outside the warranty period (or quite often within as I experienced!). These lasers are not the same quality as the originals in players from the 80s. I have a Philips 471 that still works to this day even though it hasn't seen particularly heavy use for about 20 years...One normally doesn't notice the laser failing until the servo is no longer able to consistently maintain tracking - it relies on accurate positioning to be able to read the data so if the optical signal is marginal, the servo lock is lost and the data is no longer able to be consistently read. Hence the skipping and dropouts.
The expected life of a laser would be around 2000 to 5000 hours or so which would give an average service life of up to 10 years or so assuming an hour or 2 a day.

I fear CD lasers will go the way of the tape head replacement.... No way I will find a new combination head for my DR-M44HX or DR-M24HX!
Perhaps future kids will resurrect CDs in a future revival as a quaint "vintage" playback medium ..... yeah nah!

[fetteler]

That's unfortunate Anthony; no replacements available.

These folk have then for about $100....

https://www.eeshops.net/laser-lens-diode-c-704/buy-genuine-optical-laser-lens-pickup-assy-for-vintage-denon-dcd1000-dcd1100-dcd1300-dcd1500-dcd1700-dcd300-cd-player-replacement-part-p-72718.html


Also available on Ali Express for arounf $70:

https://m.id.aliexpress.com/i/1005002112290148.html
Steve.

[pde2000]

Thanks Steve, that's a possibility then.  Not sure about spending that much on an old machine that may have other faults.  I turned it off last night and then this morning it would not read good discs so left it on.  Came back from work and its working ok again.  So yes it's wearing out but it was cheap second hand to start with.  As Anthony says, the lasers do age and the 3 beam pickups do need to be bright enough to make the tracking beams work (they use a diffraction grating to make the front and back beams apparently).

There's a thorough guide to fixing cd players with lots of explanations and links https://www.repairfaq.org/sam/cdfaq.htm

I had an old dcd1500ii die on me a few years ago and bought this and another dcd1500ii to replace when a new dcd720ae was like acid to my ears.  Funny thing is the 720ae plays mp3 via a usb socket really nicely.