Hi Udo,
I'm sure Salar would be more than pleased if you can help once we actually begin defining what this is going to look like. This is his thread and his project, I'm here to help if I can. Just part of the crowd.
-Chris
I'm sure Salar would be more than pleased if you can help once we actually begin defining what this is going to look like. This is his thread and his project, I'm here to help if I can. Just part of the crowd.
-Chris
Hi to all,
I´ve been away for a while and frankly I did not read much of the posts.
Lost lot of time in finding companies who could do a good first class Cabinets - have not found one so far - lack of skill and devotion.
I am very much in favour the linear drive design - no gears, just magnets.
Very appealing to me. I have a Sony CDP-103 for reverse engineering - anyoone out there to read the circuit diagram and explain to us, how this mech
works?
Before going down that route, maybe someone could tell why Sony scrapped them - but I still hope they simply wanted higher margins.
All the best,
Salar
I´ve been away for a while and frankly I did not read much of the posts.
Lost lot of time in finding companies who could do a good first class Cabinets - have not found one so far - lack of skill and devotion.
I am very much in favour the linear drive design - no gears, just magnets.
Very appealing to me. I have a Sony CDP-103 for reverse engineering - anyoone out there to read the circuit diagram and explain to us, how this mech
works?
Before going down that route, maybe someone could tell why Sony scrapped them - but I still hope they simply wanted higher margins.
All the best,
Salar
@Mark:
Thanks a lot!
Now we simply have to build that thing.
I will start to do the Mechanical / CAD part in January.
Someone could start look at the circuitry / reverse engineer it...?
Merry Xmas to all!
BTW, a video I made last year that might fit today:
https://www.youtube.com/watch?v=_dLBHK1mnlk
The improvisation emerging from this xmas carol is just gorgeous!!!!
Thanks a lot!
Now we simply have to build that thing.
I will start to do the Mechanical / CAD part in January.
Someone could start look at the circuitry / reverse engineer it...?
Merry Xmas to all!
BTW, a video I made last year that might fit today:
https://www.youtube.com/watch?v=_dLBHK1mnlk
The improvisation emerging from this xmas carol is just gorgeous!!!!
Hi Mark,
Good article. Should be easy for people to understand how linear slide mechanisms work.
I should point out that the actual amount of lubricant to be applied (after cleaning all the old stuff off!) is very little If you see any buildup, remove it as it will only attract dirt and hair - making a mess.
The type of lubricant to use will depend on the materials used. For metal slide rods in a sleeve bearing (the most common type), use either "FOIL" from Japan, or a very fine single weight oil with zero lubricants. This excludes sewing machine, 3N1 and WD-40 from the party. If the components are non-metallic, then use a very light white grease. The stuff from the factory seems more slippery than the normal "white grease" you can find locally.
Hi Salar,
The chip set you decide on will have most of this circuitry built in. The only things that can be tuned would be the filter and gain of any servos, sometimes DC offset too.
-Chris
Good article. Should be easy for people to understand how linear slide mechanisms work.
I should point out that the actual amount of lubricant to be applied (after cleaning all the old stuff off!) is very little If you see any buildup, remove it as it will only attract dirt and hair - making a mess.
The type of lubricant to use will depend on the materials used. For metal slide rods in a sleeve bearing (the most common type), use either "FOIL" from Japan, or a very fine single weight oil with zero lubricants. This excludes sewing machine, 3N1 and WD-40 from the party. If the components are non-metallic, then use a very light white grease. The stuff from the factory seems more slippery than the normal "white grease" you can find locally.
Hi Salar,
The chip set you decide on will have most of this circuitry built in. The only things that can be tuned would be the filter and gain of any servos, sometimes DC offset too.
-Chris
As the RF amplifier is built-into the mechanism, what external servo chipset is suitable to process e.g. the focus and tracking error signals other than the matching external chipset that might be obsolete?
Hi Jay,
Chip sets from Sanyo and others. I would prefer to use a Sony chip set, but any set that is used with the KSS-240A style head will do. The KSS-240A has the RF amp on board along with the servos.
We aren't restricted to using a head that builds in the RF amp and servos, what is the reason you are looking that way? You could build the RF amps and servo stuff onto a PCB that mounts on the transport chassis easily enough. The better servos are larger in size than the head mounted variety, so sticking this circuit on the transport achieves most of what you got with the head mounted type, but with the better performance of a main PCB mounted circuit. There isn't anything wrong with running the current signals all the way to the main PCB, but I'll agree with you that it's nice to capture and convert it earlier than later. Temper that thought with the the universal modifier "within reason".
Anyway Jay, we can go both ways and I suspect that the head without any built in electronics is the easier type to find.
Best, Chris
Chip sets from Sanyo and others. I would prefer to use a Sony chip set, but any set that is used with the KSS-240A style head will do. The KSS-240A has the RF amp on board along with the servos.
We aren't restricted to using a head that builds in the RF amp and servos, what is the reason you are looking that way? You could build the RF amps and servo stuff onto a PCB that mounts on the transport chassis easily enough. The better servos are larger in size than the head mounted variety, so sticking this circuit on the transport achieves most of what you got with the head mounted type, but with the better performance of a main PCB mounted circuit. There isn't anything wrong with running the current signals all the way to the main PCB, but I'll agree with you that it's nice to capture and convert it earlier than later. Temper that thought with the the universal modifier "within reason".
Anyway Jay, we can go both ways and I suspect that the head without any built in electronics is the easier type to find.
Best, Chris
I was thinking along this line:
(1) The chosen mechanism uses unusual tracking system. I don't know the detail but it looks like electromagnetism is used to move the sled to a huge degree, replacing the common gear for non-fine movement. The consequence might be that a common servo chip (for processing tracking error signal) might be unsuitable (but of course, nothing is impossible, including building a discrete servo from scratch).
(2) The tracking servo used with the chosen mechanism is not built-into the mechanism. It means, if we purchase the mechanism, we don't automatically get the servo chip. The servo chip might be obsolete.
But of course, with some works, the servo used in e.g. KSS 240 head, CXA 1372, might be used to process the TE (tracking error) and outputs suitable voltages for the coil that might need unique requirements.
Would using some computing power to "learn" disc errors like off centre and warping to predict servo activity instead of reacting might improve readback. Smarter handling of drop outs is also possible
From what I can see, the servo amps are not the problem. Everything is controlled by the main controller chip which needs to be programed/configured for each system. The best mechanism will be useless without a chipset to support it. And, a supplier that will help in programing it.
Not convinced this is the best design. No surprise there I hope.
Not convinced this is the best design. No surprise there I hope.
It's you who is arguing that any increase in mass over the lightest spindle simply won't work and causes problems! I'm not arguing that at all. So you define "high".
I am telling you that the CDM0 mech had a much higher angular momentum than today's mechs and it worked and still works absolutely perfectly, mine keep working and are 30+ years old now.
I'm telling you that my TEAC CD701 has a much higher angular momentum than any standard modern mech and even higher than the CDM0 and it works absolutely perfectly and has done for over 20 years! Track selection is fast too. How can that be? Must be a miracle!
You are telling me that a higher mass cannot work and should never be part of a design because it will cause problems. Yet there are thousands and thousands of machines out there using just the two mech examples above which prove you wrong. And there are further designs with added mass, brass pucks etc etc all working perfectly well, sounding great and also with great track selection speeds.
So... it would appear that you are arguing from a point of view of design philosophy and idealism, not practical reality or even from a point of evidence - the evidence to the contrary is all around you, even if you didn't like repairing some of them and personally saw the engineering as a gimmick.
I can only guess that you are somehow thinking that "high mass", when I'm talking about it here, is of some order of kgs? That's why I ask you to tell me what you're talking about when you say "high mass - there's no point us talking about different things.
And then goes on to drool all over the Esoteric P2 :
EsotericP2
I'm not sure if the motor really is from a BU-1 because I thought it was bespoke looking at it.. but if so, just goes to show what a well built mech's motor can handle absolutely fine.
Well, yes I agree! It is a matter of considering what benefits could be gained by some method with would end up adding mass..
Anatech and you previously seemed to be saying, in this thread for designing a new mech, that all thoughts of anything potentially beneficial must be not considered simply because it might add mass to the spindle.
I'm saying that when desiging something to be high end, all aspects should be looked at and their benefit assessed. I don't think ideas should be dismissed without their potential benefits considered just because it doesn't fit with an idealised notion of what a mech should be like..
That's the only point I'm making really - shame it gets dragged down in spurious technical points.
As far as I remember, Kenwood did something similar in 2nd generation players.
When a scratch occured, tracking gain was lowered. But maybe this
was / is relatively common
NATDBERG, I don't think anyone is claiming that high mass can't work. There is just no advantage in doing so and only disadvantages. Why make the investment in something that is not an improvement to a design. The problem here is that many of the design choices are made without knowledge of how a CD works or the sub-systems in the player. There is no open comparing of designs, so how do you know which is best. What are the advantages and what are the disadvantages. It is far to easy to just say that a design is used because it is cheaper and not because of the higher requirements of ROM or DVD.
I understood it being said that one shouldn't add mass because if x, y and z and hence a little condescending attitude of 'it's not a turntable' was coming out. That is understood 'that it's not a turntable' but adding mass doesn't cause too many problems as shown by example so anyone designing a good mech should not be too concerned about mass within reason if the reason for adding it has the possibility of helping the design in any way..
I gave the evidence of an experienced CD player designer from the early days (80s/90s) finding a CD flattening system beneficial in both reducing errors and subjectively. The system would have added mass though which was the argument against on here it seems. It was a money no object design so cost considerations vs sonic advantage wasnt an issue.
Hope you're all having a good Christmas though! I hope were all on the same page in that it's only a discussion about mechs.. nothing serious.
I gave the evidence of an experienced CD player designer from the early days (80s/90s) finding a CD flattening system beneficial in both reducing errors and subjectively. The system would have added mass though which was the argument against on here it seems. It was a money no object design so cost considerations vs sonic advantage wasnt an issue.
Hope you're all having a good Christmas though! I hope were all on the same page in that it's only a discussion about mechs.. nothing serious.
Hi NATDBERG,
You have not yet given any evidence of anything, nor do you have direct experience adjusting / fixing any CD transport. Yet, you feel justified in arguing with two people who do have a long direct experience with working with CD / DVD transports. You are merely a voice in the nose bleed section attempting to cause trouble at the expense of every other serious member who even reads this thread. You are attempting to drag it off topic at every opportunity.
This is not a thread where you are going to be educated beyond what has been explained to you thus far. It isn't fair to the other members or the original poster, so either accept what you've been told, or be quiet. Go learn disruptively somewhere else.
I'm not going to dignify your latest comments with any answers. You are making claims that are lacking factually on subject matter that has been covered all ready. In fact, you are beginning to look like a troll.
-Chris
You have not yet given any evidence of anything, nor do you have direct experience adjusting / fixing any CD transport. Yet, you feel justified in arguing with two people who do have a long direct experience with working with CD / DVD transports. You are merely a voice in the nose bleed section attempting to cause trouble at the expense of every other serious member who even reads this thread. You are attempting to drag it off topic at every opportunity.
This is not a thread where you are going to be educated beyond what has been explained to you thus far. It isn't fair to the other members or the original poster, so either accept what you've been told, or be quiet. Go learn disruptively somewhere else.
I'm not going to dignify your latest comments with any answers. You are making claims that are lacking factually on subject matter that has been covered all ready. In fact, you are beginning to look like a troll.
-Chris
The evidence is not very convincing or the wrong conclusions drawn. Experts talk about switching off the error correction and error reduction by flattening the disc, not increasing the mass. You could do some testing. Build a flattening device and see if the error correction is reduced. I know someone who actually did something like this by scratching discs until the error correction failed and then applied his product.
Keep it friendly guys.
NATDBERG, the theory of Redbook playback and data recovery is well established, in fact I spent 3 days with Sony in the early years, and servo design (covering focus/tracking/spindle) and how it all integrates and comes together as a whole was a major part of the course.
Over the years, a lot of myth and legend has appeared as to what may provide beneficial tweaks, or where the big designers got it wrong......
While its fine to put forward those ideas, you also need to back them up with real evidence that shows not only an improvement in performance, but also that it is not to the detriment of other areas of operation.