You have misunderstood me completely, because you put out individual sentences of me as a quote from the overall context, and then you release your reply.
Please note: All statements in my post # 173 I've heard as the opinion from some other music lovers.
This means at the same time, that this statements are not my own opinions.
However - by reading your replies, each reader think, this would be my own opinion.
In the moment I know not enough about the technology of HDD player and thus I haven't my own statements concerning pros and cons.
That is the reason why I want to know the best threads here on diyaudio about the topic "HDD"
Unfortunately your comments here are not very helpful for me.
This is true by all me known optical pick up models except Sony's KSS series (especially KSS-210 and above, if inside the diode model SLD-104U) and Philips CDM12.xx series without genuine Sharp Hologram laser diodes
Concerning the spindle/disc motor I always note, that from the not brushless versions the brand "Mabuchi" has the highest reliability, although these are very inexpensive.
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Hi tiefbassuebertr,
My response addressed a number of posts you have made on the subject. The repetition of opinions from other people isn't going to help anyone either as it's easy to assume they are your opinion. Take the various weights you posted. An understanding of how a CD player works (or DVD or even HDD player) should make it obvious that any added rotating mass is detrimental to a low error read back of the information. It should also be noted that the frequency response of the servos has been tuned to the expected mass being rotated. Play with that and you end up with a servo system that has been detuned.
The later Philips laser heads are just awful. The quality is extremely variable, and even new ones are apt to be bad. However, experience with both Philips and Revox (and Studer) CD players has taught me to avoid the Philips transport. There can be other issues apart from just the laser diode assy. Aligning a laser diode is not for anyone who values their time.
-Chris
My response addressed a number of posts you have made on the subject. The repetition of opinions from other people isn't going to help anyone either as it's easy to assume they are your opinion. Take the various weights you posted. An understanding of how a CD player works (or DVD or even HDD player) should make it obvious that any added rotating mass is detrimental to a low error read back of the information. It should also be noted that the frequency response of the servos has been tuned to the expected mass being rotated. Play with that and you end up with a servo system that has been detuned.
I'm sorry, but I don't understand what you are trying to get across here. What is a "Hologram laser diode" for instance? I am not making fun of you, I honestly don't understand that sentence. A language issue.
There are some cheap and nasty motors out there for sure! However, even some brush-less motors can be unreliable. The Denon DCD-3300/DCD-1700 CD players come to mind.
The later Philips laser heads are just awful. The quality is extremely variable, and even new ones are apt to be bad. However, experience with both Philips and Revox (and Studer) CD players has taught me to avoid the Philips transport. There can be other issues apart from just the laser diode assy. Aligning a laser diode is not for anyone who values their time.
-Chris
Hi john dozier,
Don't bother replacing the RCA with a BNC. It will not buy you anything at all. There is nothing at all wrong with a half decent RCA connector. I deal with BNC cables every day. Want a better connector? Consider an "N" or "UHF" connector. Mind you, they are large. An SMA connector might be better, and there are other more expensive connectors you can try. I'd just leave that alone.
Teac and Tascam generally put out some really well built transports. However, they have also sold some real "dogs" in their high end units too. I'm not familiar with the newer machines at all, you could certainly do worse. But, you can not just assume they will be selling the best either.
I liked the machines that used a Sony head the best.
-Chris
Don't bother replacing the RCA with a BNC. It will not buy you anything at all. There is nothing at all wrong with a half decent RCA connector. I deal with BNC cables every day. Want a better connector? Consider an "N" or "UHF" connector. Mind you, they are large. An SMA connector might be better, and there are other more expensive connectors you can try. I'd just leave that alone.
Teac and Tascam generally put out some really well built transports. However, they have also sold some real "dogs" in their high end units too. I'm not familiar with the newer machines at all, you could certainly do worse. But, you can not just assume they will be selling the best either.
I liked the machines that used a Sony head the best.
-Chris
Changing to BNC is purely for convenience as my DAC has BNCs and I have a number of BNC to BNC cables. I also agree with the comments about Tascam, but it is a rack mount unit and is used in broadcasting. Having been the General Manager of a number of public radio stations, I know something about Tascam reliability-so at least it will work. I also see few used units for sale or questions about repair on the Tascam forums. And if it sounds like crap, I can always sell it and recover at least 3/4 of my SUBSTANTIAL INVESTMENT of $250. Regards
Hi John,
That's fair enough. It just sounded as if you were being guided by the audio press. This last comment puts the jack change in it's proper context and wouldn't be misunderstood by others who are at the mercy of what circulates as "knowledge" out there. Eliminating an adapter or special cable is always a reasonable idea.
I was "factory warranty" for Tascam for many years. Their better CD players for industrial use tend to be a good bet. For years, my favourite machine was the CD-401. Funny that, it was an old machine - ancient by now, and I wouldn't mind having one. However, sometimes their audiophile offerings have features guided by the sadly misguided. CD-701 comes to mind. While not a bad player, it wasn't any better than several less expensive models. More $$ often does not get you a better product once you are above a certain price point.
-Chris
That's fair enough. It just sounded as if you were being guided by the audio press. This last comment puts the jack change in it's proper context and wouldn't be misunderstood by others who are at the mercy of what circulates as "knowledge" out there. Eliminating an adapter or special cable is always a reasonable idea.
I was "factory warranty" for Tascam for many years. Their better CD players for industrial use tend to be a good bet. For years, my favourite machine was the CD-401. Funny that, it was an old machine - ancient by now, and I wouldn't mind having one. However, sometimes their audiophile offerings have features guided by the sadly misguided. CD-701 comes to mind. While not a bad player, it wasn't any better than several less expensive models. More $$ often does not get you a better product once you are above a certain price point.
-Chris
by post #8 about
http://www.diyaudio.com/forums/digital-source/118902-stripdown-clean-cdm12-4-a.html
you will find a picture of a Sharp Hologram Laserdiode
and about
http://www.datasheetcatalog.org/datasheet/Sharp/mXqxuqy.pdf
a datasheet.
And here various patents:
http://www.freepatentsonline.com/7173951.pdf semiconductor laser device with light receiving element 6. Feb 2007
http://www.freepatentsonline.com/6683897.pdf semiconductor laser device 27. Jan 2004
http://www.freepatentsonline.com/5557116.pdf semiconductor laser device and resin layer 17. September 1996
http://www.freepatentsonline.com/5511059.pdf grating beam splitter 23. April 1996
http://www.freepatentsonline.com/6388977.pdf optical Pick Up device 14. Mai 2002
for this reason I start this thread two years ago:
http://www.diyaudio.com/forums/digi...lt0h30pa-inside-philips-cdm12-vam12-mech.html
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I'm sorry for the misunderstanding. Reading the comment from post #181 would have to provide clarity
Don't rise your hopes getting a high quality drive. I had the Tascam CD-500 in my place for some dayes. It was not as good as my stable plater drive as transport and the sound quality of the analog out was not good too (if you are looking for high end quality). The slot in mechanism was just horrible (for me).
I wouldn't say it was completly bad. Maybe quite good indeed. Just not "high end" in terms of sound and mechanical quality.
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This is not slot load but drawer load with a newly designed mechanism. I have had excellent results using it with an Andedio D1. Of course, the Anedio has superb jitter reduction so your results may vary, but I am very pleased. I do not expect it to be as good as their Esoteric drives, but at one tenth the cost, I am pleased.
i cannot believe some of the things here written by techs and non techs. Sorry guys but most of the sony transports including many japanese made fail. However the early philips transport still rated the best ever and almost never fail. Still for sound if not known one of the early philips drive cd players that uses philips transport with 4 or 5 philips td chips blows away still all past and present cd players. Real shame these modern transports are put in the same class as the early philips. And its a shame that these so called high end multithousand dollar cd players are fitted with cheap crappy sony sanyo drives that will fail eventually. Now that is a rip off to the wealthy buying consumer. Why isnt that ever brought up?
Hi veeman,
They had a nasty failure mode. The x-port suspension would sag. Murder to troubleshoot, difficult to prove, repair by replacement. Service prices on transports were higher than a new unit. Go figure.
I serviced the Marantz CD-73, Philips and Mission, plus Revox and Studer CD players. I just might be familiar enough with the early and later Philips stuff to comment with some authority. I'm certainly not the only one either.
Good service techs post what their actual experience is. So I guess the question must be asked. What experience do you have, and does it give you the right to pass judgement on this group of people?
-Chris
Everything fails after some time in service. I would like to see where you are getting your information from. It is a fact that most repair technicians replace laser heads unnecessarily. Much like picture tubes were the #1 replacement part in the early TV days. The better Sony and NEC heads are very good, and they play for thousands of hours before the head becomes weak.
Hang on to that thought if it makes you feel better. It isn't even close to being true. I serviced those machines under and out of warranty. Believe it, the early Philips mechanisms failed all right! But the alignment procedure was so horrible that it was best left to the factory. Philips sold their stuff cheap, but service equipment was the most expensive. Test CD 5 and 5A were $450 if you had an account with Philips.
They had a nasty failure mode. The x-port suspension would sag. Murder to troubleshoot, difficult to prove, repair by replacement. Service prices on transports were higher than a new unit. Go figure.
Aaaaah ... no. Not even close. I still have some chip sets, and if you think a TDA1541A sounds better than the new product, you have never heard anything of note. These are non-oversampling chips! They do require the 7th order filters on the outputs to keep the 44.1 KHz out of your system. Every non-oversampling DAC still needs that 7th order filter. There is no way to be nice about it.
I serviced the Marantz CD-73, Philips and Mission, plus Revox and Studer CD players. I just might be familiar enough with the early and later Philips stuff to comment with some authority. I'm certainly not the only one either.
I agree completely, but this wasn't ever the focus of this thread. BTW, many of those will fail right out of the box.
Do me a favor and read the title of this thread. Do you think we want to talk about bottom of the barrel junk transports, or maybe we are looking at the better transports?
Good service techs post what their actual experience is. So I guess the question must be asked. What experience do you have, and does it give you the right to pass judgement on this group of people?
-Chris
Hello Chris, nice to have you here!
I started this thread: http://www.diyaudio.com/forums/digi...nting-swing-arm-mechanism-looking-allies.html
Maybe we can do it better than Philips.
But I can confirm veeman. I checked a player where the OEM manufacturer gives the choice of using pin compatible Sony or Sanyo transports. Sony is a plastic nightmare they saved the second steel rail and use the plastic frame for "guiding".
Sanyo is better with metal frame and two steel rails, standard Mabuchi Motors, but both transports do not use copper bearings any more. And both transports have mechanical play, because the gears are not tensioned with springs. My Sony from 1996 outperforms those "modern" players on
heavily scratched discs easily.
I started this thread: http://www.diyaudio.com/forums/digi...nting-swing-arm-mechanism-looking-allies.html
Maybe we can do it better than Philips.
But I can confirm veeman. I checked a player where the OEM manufacturer gives the choice of using pin compatible Sony or Sanyo transports. Sony is a plastic nightmare they saved the second steel rail and use the plastic frame for "guiding".
Sanyo is better with metal frame and two steel rails, standard Mabuchi Motors, but both transports do not use copper bearings any more. And both transports have mechanical play, because the gears are not tensioned with springs. My Sony from 1996 outperforms those "modern" players on
heavily scratched discs easily.
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Hi Salar,
Hey, always a pleasure!
I haven't seen the newer stuff yet, but since we were dealing with history here, my points are valid. We can only compare similar vintage products. If we want to talk newer transports, the Philips still hits the dirt first. However, I wouldn't want any cheapy CD transport. It seems like the best transports to have would be ones using the Sony KSS-210A, KSS-240A and KSS-151A (the linear motor one in case the model number is wrong). The Sony chip sets seem to be the better ones for servo and tracking behavior.
The reason the tracking isn't good is that the eye pattern is poor. Bad head, bad geometry and poor components = junk. The plastic Sony can be beat into better shape if that plastic rail is held on by screws you can play with (then lock-tight). Without real bearings you are fighting a losing battle anyway. Repair by replace.
The Philips radial arm tracking has two major problems. One is aligning that laser head, the other is breaking flexible PCBs. A similar problem with the Sony 5-disc, breaking the flexible PCB and they do not stock it. Very underhanded of them. Can't say I'm a fan. The linear tracking head is far easier to service and get aligned properly. Its also easier to keep it running over time.
I'll pop into your thread Salar - thanks for the directions to it!
-Chris
Hey, always a pleasure!
I haven't seen the newer stuff yet, but since we were dealing with history here, my points are valid. We can only compare similar vintage products. If we want to talk newer transports, the Philips still hits the dirt first. However, I wouldn't want any cheapy CD transport. It seems like the best transports to have would be ones using the Sony KSS-210A, KSS-240A and KSS-151A (the linear motor one in case the model number is wrong). The Sony chip sets seem to be the better ones for servo and tracking behavior.
The reason the tracking isn't good is that the eye pattern is poor. Bad head, bad geometry and poor components = junk. The plastic Sony can be beat into better shape if that plastic rail is held on by screws you can play with (then lock-tight). Without real bearings you are fighting a losing battle anyway. Repair by replace.
The Philips radial arm tracking has two major problems. One is aligning that laser head, the other is breaking flexible PCBs. A similar problem with the Sony 5-disc, breaking the flexible PCB and they do not stock it. Very underhanded of them. Can't say I'm a fan. The linear tracking head is far easier to service and get aligned properly. Its also easier to keep it running over time.
I'll pop into your thread Salar - thanks for the directions to it!
-Chris
Under post #166 I have mentioned various mechanism models. My favorites are the Philips CD-mechanism with swing arm in use (CDM-0 until CDM-4, still good available as refurbished version or in older Philips CD player models, good to find in used condition) so as the JVC mechanism JVC EXU-901A with JVC's Optical Pick Up "Optima 4" (unfortumately very hard to find, because not in use by cheap cd players).
VAM and VAU-units I hate because the very hard to find replacement laser unit in genuine quality (mostly china copy quality). Even by the pick up versions from first equipment (CDM12.4 head) there are a plastic lens in use.
In this case I started several threads, e. g.
http://www.diyaudio.com/forums/digi...lt0h30pa-inside-philips-cdm12-vam12-mech.html
http://www.diyaudio.com/forums/digital-source/118902-stripdown-clean-cdm12-4-a-2.html
http://www.diyaudio.com/forums/digi...why-various-die-casting-carrier-design-2.html
http://www.diyaudio.com/forums/digi...1254-cdm12pro-vau1254-cdm12-4-compatib-2.html
Best currently offers for good cd players with swing arm are this:
http://www.ebay.de/itm/Micromega-TR...267658?hash=item36104629ca:g:qlAAAOSwQjNW8wug
http://www.ebay.de/itm/KRELL-MD-2-C...D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
http://www.ebay.de/itm/MICROMEGA-CD...136359?hash=item51f219ed27:g:lpwAAOSw-0xYdNwt
Are there diy cd mechanism realized in the meantime ?
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Ah - this question catches me in a very low moment - just blew the logic of a CD-304. 
Backstory: I bought two CD-104, one CD-304 and CD-304MKII
for evaluation.
Also want to put the electronics in a nice, self designed enclosure and had to cut the display pcb in size and rewire some things. Also cleaned it with water and rinsed with alcohol, retinned the (open) traces. Let it dry for two days on the heater but something went wrong and bang. First thought of short circuit, but it is ok. Brittling noise from the display-pcb, without the microcontoller in action, all segments except four are lit. Also the servo board got a hit, laser swings in wrong direction.
I still have two CD-104 and one 304MKII left, but this is still very annoying,
because the 304 "Mark One" I blew was nevertheless in bad shape but working condition.
I bought four units also because I want to experiment on replacing the diodes.
But after today´s experiences I am very hesitant.
Some interesting findings:
The manuals of those CDM-1 players state a 1V p-p amplitude of the eyepattern. Only exception is CD-960 with 1.5V.
Anyway, eyepattrens were higher than that, I reduced them to 1V. Probably Philips was wrong in the service manuals to state 1V and 1.2V is more likely.
But strange they did this for at least 4-5 models.
With 1V p-p, nd they still play without flaws, even burned CD´s.
No differences in error correction
The CD 304MKII has the best error correction of all four players i have - plays gaps of 4x1.5mm without clicks. And all players came to me in poor condition, obviously they were stored in a humid celler for a long time.
The other three are less than average, they already click on 4x0.75mm.
Also very odd: Laser trimpots are very different in position with the same Voltage. They vary between midpoint to almost completely cranked up.
First I thought the previous owners played with them, but I found CDM -1 photographs on the net also with trimpots in high position. Maybe they have a lot of tolerance.
I am still looking for a CDM-1 with dead laser to check possibilities of laser diode repacement.
Was not successful with three beam, diffraction grating is the big problem here.
With Philips, no diffraction grating. Also the laserdiode, SharpLT022MC,
seems to fit tightly in the RAFOC, the laser unit. One can turn it clockwise
or counterclockwise, (just by some degrees) adjust the height of the pin that houses the diode, that´s it. No horizontal play like in Sony designs.
Still have to disassemble the CDM-1 for better cleaning, still thinking of a way
to mark the positions of the screwheads to reassemble without much alignment.
All the best Salar
Backstory: I bought two CD-104, one CD-304 and CD-304MKII
for evaluation.
Also want to put the electronics in a nice, self designed enclosure and had to cut the display pcb in size and rewire some things. Also cleaned it with water and rinsed with alcohol, retinned the (open) traces. Let it dry for two days on the heater but something went wrong and bang. First thought of short circuit, but it is ok. Brittling noise from the display-pcb, without the microcontoller in action, all segments except four are lit. Also the servo board got a hit, laser swings in wrong direction.
I still have two CD-104 and one 304MKII left, but this is still very annoying,
because the 304 "Mark One" I blew was nevertheless in bad shape but working condition.
I bought four units also because I want to experiment on replacing the diodes.
But after today´s experiences I am very hesitant.
Some interesting findings:
The manuals of those CDM-1 players state a 1V p-p amplitude of the eyepattern. Only exception is CD-960 with 1.5V.
Anyway, eyepattrens were higher than that, I reduced them to 1V. Probably Philips was wrong in the service manuals to state 1V and 1.2V is more likely.
But strange they did this for at least 4-5 models.
With 1V p-p, nd they still play without flaws, even burned CD´s.
No differences in error correction
The CD 304MKII has the best error correction of all four players i have - plays gaps of 4x1.5mm without clicks. And all players came to me in poor condition, obviously they were stored in a humid celler for a long time.
The other three are less than average, they already click on 4x0.75mm.
Also very odd: Laser trimpots are very different in position with the same Voltage. They vary between midpoint to almost completely cranked up.
First I thought the previous owners played with them, but I found CDM -1 photographs on the net also with trimpots in high position. Maybe they have a lot of tolerance.
I am still looking for a CDM-1 with dead laser to check possibilities of laser diode repacement.
Was not successful with three beam, diffraction grating is the big problem here.
With Philips, no diffraction grating. Also the laserdiode, SharpLT022MC,
seems to fit tightly in the RAFOC, the laser unit. One can turn it clockwise
or counterclockwise, (just by some degrees) adjust the height of the pin that houses the diode, that´s it. No horizontal play like in Sony designs.
Still have to disassemble the CDM-1 for better cleaning, still thinking of a way
to mark the positions of the screwheads to reassemble without much alignment.
All the best Salar
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Hi weissi,
Getting back to the title of the thread, nothing has changed.
The NEC transport used in the Alpage and Nakamichi OMS5/7 is the best transport ever sold to the public - ever. The eye pattern was the clearest, most stable and had the fewest digital errors of anything else on the planet. I still have my OMS-7 CD player.
The reason for this is that the mechanics are completely adjustable le:you could align the laser head exactly to the plane of the CD. Once done, you align the servos which now need to do very little correction.
The radial arm Philips transports (early) did the same approximate thing with their alignment. Not as good or effective, but close enough for rock and roll. Good eye pattern, but not as good as the NEC. Failures were the suspension of the lens and the flex cable. I own some Studer machines.
No other transports later than these attempted to align the head to the plane of the CD. A much less good eye pattern results with far greater noise. Philips moved to using the same cheap motor as everyone else (great! can be serviced now). The Sony mechanisms were serviceable and could produce a better eye pattern than the Philips. Many other cheap mechanisms appeared that wore out quickly. The Sanyo SF-90 heads could produce a nice eye pattern when new. No slide bearing - as real shame. They would wear quickly.
Later mechanisms became very cheap with terrible eye patterns. Don't even begin to talk about quality! They don't sound good. Lots of digital errors that are not correctable, but they can be hidden. So your modern transport normally relies on the DSP to hide their problems.
"Stable platters" add rotating mass and prevent the disc motor from correcting the linear velocity of the track quickly as required. A stable platter always increases errors, but it is a sweet idea for consumers who don't understand how CDs work. It ain't a turntable folks! CEC even made a belt drive CD player! That demonstrates how easy it is to sell crap to consumers. Again, the motor cannot correct errors in linear velocity quickly resulting in digital errors.
A spinning CD doesn't wobble. It can be warped, and if it is, a stable platter does not clamp with enough pressure to flatten it. Those claims are false and relate back to an LP on a turntable with weighted clamp (or a pressure clamp). There, an LP is pliable enough to be flattened, but a CD is stiffer and smaller. It does not bend easily folks.
"stable platters" are a farce, period.
-Chris
Getting back to the title of the thread, nothing has changed.
The NEC transport used in the Alpage and Nakamichi OMS5/7 is the best transport ever sold to the public - ever. The eye pattern was the clearest, most stable and had the fewest digital errors of anything else on the planet. I still have my OMS-7 CD player.
The reason for this is that the mechanics are completely adjustable le:you could align the laser head exactly to the plane of the CD. Once done, you align the servos which now need to do very little correction.
The radial arm Philips transports (early) did the same approximate thing with their alignment. Not as good or effective, but close enough for rock and roll. Good eye pattern, but not as good as the NEC. Failures were the suspension of the lens and the flex cable. I own some Studer machines.
No other transports later than these attempted to align the head to the plane of the CD. A much less good eye pattern results with far greater noise. Philips moved to using the same cheap motor as everyone else (great! can be serviced now). The Sony mechanisms were serviceable and could produce a better eye pattern than the Philips. Many other cheap mechanisms appeared that wore out quickly. The Sanyo SF-90 heads could produce a nice eye pattern when new. No slide bearing - as real shame. They would wear quickly.
Later mechanisms became very cheap with terrible eye patterns. Don't even begin to talk about quality! They don't sound good. Lots of digital errors that are not correctable, but they can be hidden. So your modern transport normally relies on the DSP to hide their problems.
"Stable platters" add rotating mass and prevent the disc motor from correcting the linear velocity of the track quickly as required. A stable platter always increases errors, but it is a sweet idea for consumers who don't understand how CDs work. It ain't a turntable folks! CEC even made a belt drive CD player! That demonstrates how easy it is to sell crap to consumers. Again, the motor cannot correct errors in linear velocity quickly resulting in digital errors.
A spinning CD doesn't wobble. It can be warped, and if it is, a stable platter does not clamp with enough pressure to flatten it. Those claims are false and relate back to an LP on a turntable with weighted clamp (or a pressure clamp). There, an LP is pliable enough to be flattened, but a CD is stiffer and smaller. It does not bend easily folks.
"stable platters" are a farce, period.
-Chris