PIONEER PD-91 CD Player (1987/1990), how to dial in for optimal CD-R playback

thought i'd start a dedicated thread on how to enable the vintage classic PIONEER ELITE series
PD-91, PIONEER's very first ELITE series CDP, to more reliably read CD-Rs.

((NOTE; the PD-91 is a notoriously finicky CDP in regards to CD-Rs, and, even after this adjustment, it can be rather crotchety about them, apparently due to CD-R brand/reflectivity/CD Burner/ETC. as such, while this adjustment IS absolutely beneficial to the PD-91's CD-R read tolerances, it IS NOT, unfortunately, a cure-all that will enable the player to read everything you throw at it. in fact, the player will often take 30secs./1min. to read the TOC, and/or sync to a track and begin play,
on many CD-Rs. others, it will read just fine, usually taking just a wee bit longer to sync up than it would reading a garden variety Redbook factory CD. in fact, this adjustment speeds up the players
handling of factory CDs, to the degree where the player will nominally read TOC and/or begin playback in less than a 1/2 second. just remember that this is a fussy machine, for whatever reason, with homegrown CD-Rs, and that your personal mileage will most likely vary with your copy
of this magnificent, yet temperamental machine...))


- PD-91, with top aluminum panel removed -

((NOTE, unless you have modded this player as i have, and bummed the alum top plate from
from either the Japanese market PD-3000, or -5000, or from the U.S. PD-93,
then your U.S. and/or EURO/WORLD version PD-91 will require removal
of 16 screws, both rosewood panels, and the pressed sheet metal top bonnet
in order to gain access to the player interior))





now then. there is a series of Variable Potentiometers on the section of PCB directly aft
of the disc transport cage/assy;






there are only TWO of these that you want to mess around with.
VR-3 and VR-4, FOCUS GAIN and TRACKING GAIN, respectively.

BOTH are located at the far right, right beside the black-anodized heatsink
vertically mounted on the central stay/DIGITAL section shield;



you will want to adjust these, counter-clockwise, to the positions shown
in that photo directly above.

do this, while attempting to play a CD-R. it should sync/read the disc at those positions
illustrated above. if not, then load another CD-R until it is successfully read.

further adjustment MAY be necessary, if your 91's laser pick-up is tiring out.
in fact, if it is too heavily worn, it may not read ANY CD-R, even if it still spins
factory discs just fine. as always, your personal mileage may vary.


also, please bear in mind that i am NOT a skilled Technician.
i have no electronic service education whatsoever, and this advice is wholly based
on my limited personal self-taught experience.

that said, someone reading this out there just might know how to dial this player
in for smooth CD-R operation better then i do, and may have had better success with it than
me. if that person is out there, then, please, by all means, contribute to this thread...

 

Personally why mess with it. It wasn't designed for CDR playback, right. You might cause it to malfunction. Just my personal opinion. Nice unit (and pictures) by the way.

 

Thanks for sharing your experience!

 

I used my old PD-91 for CD-R playback early on, around 1994 or 1995, and it worked fine. My opinion is that the problem you have is that the pickups go bad over time in terms of alignment and mechanical performance. I'm not convinced that they can be easily fixed; this is like an car transmission going bad. The engine may be fine, and the brakes work, but if the transmission is bad, the car ain't gonna move.

This is a problem with tons of 20-year-old CD players, not just this one.

 

the LD pickup must be far better built in the DENON DCD-1500,
as my personal copy is of 1987 manufacture, and all throughout the two/three years i used it before acquiring the PD-91, it read and played damned near every CD-R i ever loaded into it.

AFAIK, my PD-91 is still equipped with it's factory LD pickup.
PIONEER has this player's pickups (PWY1004) still available, $144.00 per copy,
and they seem to be no older than late 1990's vintage,
as i have seen copies available on EBAY that were factory sealed
with labels with the 1998/present PIONEER logo on them.

so, are you asserting that if i was to purchase one of these
relatively brand-spanking-new production LD pickups,
that it would likely solve my PD-91's CD-R issues?


bear in mind, that my -91's current, presumably original LDP reads every factory pressing i load it with
as if the player was made yesterday...

 

I love that CD player, but it's pictures are in almost 40% of the Audio threads.

Beautiful piece of equipment and understand your pride.

 

I would buy the laser pick up while there's still some NOS around, you won't find a nice player for $150, I bet the mechanisms work incredible and will continue to work like that for a long time, add that to a new laser (perhaps check some capacitors), maybe a dac upgrade in the future and you have playback for a few more decades

 

I think your laser is getting marginal (reading CD-R is a sign of laser health). Your player has a decent laser but it's life will not be horribly long. Some old players will do a better job than others on CD-R. My 1984 Magnavox FD 1010 SL will still read CD-R well but I'm limiting how many I play on it, even though I have spare CDM-1 mechanisms for mine. Do get a NOS laser for your player while you can since you love your Pioneer.

 

i'll put that on the short list.

hopefully i'll be able to get at least two spares, within the next year,
in addition to a replacement for my 91's current, original LDP,
before they are all said and done.

fortunately, this is a VERY common pick-up,
that PIONEER kept in production for a VERY long time.

as far as i have been able to tell, in fact, -and i've done plenty of research on the subject-
is that PIONEER developed the PWY-1004 series LDP in 1987, with the PD-3000/91 series TOTL CDPs being it's inaugural first application,
and PIONEER continued to use variations of the same exact basic design
in most of the mid to TOTL CDPs they made, both single and changer,
AT LEAST well into the 1990's.

as such, i figure, in the worst case scenario, at least, that i can have a professional
retrofit one of this PWY-1004 LDP's many sister models (many of which are still quite available NOS themselves)
into a 1004 series-compatible pick-up, as, the ONLY difference i am aware of,
between all of these variations on the same basic LDP chassis,
is the flexi-ribbon lead cable that couples the LDP to the main PCB.

the LDP chassis, as i said, is IDENTICAL in all sister models,
so i do not see why a pro would not be able to retrofit
a 1004 flexi-ribbon lead onto any of the 1004 sister models,
as the connections from lead to LDP body are all EASILY accessible
to a properly grounded, fine-tipped, and heat-controlled soldering iron...

 

well, i'm QUITE happy now...

just last night, i opened her up again, and decided to take a careful inspection of the transport assembly.

i removed the stabilizer cage, and ejected the disc tray, before POWER OFF.
i went to inspect the LD pickup on it's floating electromagnetic linear motor mount, and... SOMETHING just did not look right about it.

so, i went and undid the small PHILLIPS head screw and HEX-head bolt
that holds the short shaft in place, that slides through a hole in the
pickup body, and mounts into lugs on the linear motor's pickup mounting cradle, and removed the pickup from the player chassis.

after inspecting it some, i carefully reinstalled it, making sure
that it was firmly and correctly in place, and tightly locked it down
with the copper retaining plate held in place by that PHILLIPS and HEX.

i test it out, and, lo-and-behold, IT READS CD-Rs... every bit as fast (1/2 sec. or less) as it does factory discs!!

in fact, i go into an orgy of CD-R pulling right on the spot,
AND IT READS/PLAYS EVERY ONE OF THEM... in a 1/2sec. or less!!


i think i just solved the problem.

that copper retaining plate i mentioned, that secures the pickup
retaining shaft in place, was not secured tightly when i first got to it, (the PHILLIPS screw was fine, but the HEX-bolt was loose)
and, if the LDP, as a result, wasn't thrown out of place at some time in it's past,
then it evidently amost certainly was, during shipment to my OREGON home, from the original seller, down in TEXAS.

evidently, i can only assume,
the pick-up was poorly installed in the factory, or, much more likely,
a replacement was sloppily installed by a careless service tech
at some time in this player's history.

apparently, that threw off the alignment of the pick-up
to where it had tre greatest difficulty handling CD-Rs...
though it did not seem to affect the handling of factory discs,
i suppose since they are so much easier for any optical drive to read.


at any rate, it does not seem that the seller of this player, the self-proclaimed original owner, lied to me after all,
and that this player WAS seldom used... at least since it's last LD pick-up replacement... if it actually ever had one, that is...

 

Good for you. Enjoy your vintage machine.

 

just to update; i'm quitye convinced now that tightening the LD pickup down
in it's mounting cradle in my PD-91 totally did the trick.

it spins up just about anything i load into it now,
including certain CD-Rs that it once refused to even read the TOC on...