Hi Salar,
It is infinitely easier for me to just measure the thing. I don't have the time to go through the manual, and I would merely have to confirm what I read in there anyway. I don't recall having to deal with this signal in a way that I have had to with the swing arm types of machines. It could be a factory set thing as well, no mention in the manual.
The only things that a single vs three beam system will change are the head and the RF amp and tracking portions of the circuitry. You are perfectly safe in designing the mechanical portions, they will not change.
If we can replicate the eye pattern that an OMS-5 / 7 produces, I care not how we get there! I'm not invested in either single or three beam setups. An aligned OMS 5/7 will track almost anything - such is the power of getting all the mechanical set up exactly right. The difference is not minor between this and a standard three beam setup. Good three beam CD players will also track almost anything too. Note that "good" has no bearing on price. Some of the very expensive machines I have seen are not very good machines.
-Chris
It is infinitely easier for me to just measure the thing. I don't have the time to go through the manual, and I would merely have to confirm what I read in there anyway. I don't recall having to deal with this signal in a way that I have had to with the swing arm types of machines. It could be a factory set thing as well, no mention in the manual.
The only things that a single vs three beam system will change are the head and the RF amp and tracking portions of the circuitry. You are perfectly safe in designing the mechanical portions, they will not change.
If we can replicate the eye pattern that an OMS-5 / 7 produces, I care not how we get there! I'm not invested in either single or three beam setups. An aligned OMS 5/7 will track almost anything - such is the power of getting all the mechanical set up exactly right. The difference is not minor between this and a standard three beam setup. Good three beam CD players will also track almost anything too. Note that "good" has no bearing on price. Some of the very expensive machines I have seen are not very good machines.
-Chris
Hi Salar,
Yes, I couldn't resist the urge to see what was inside.
If I can find it, I'll post a picture. As I recall (clearly), each element of the optics was arranged in line so you could very clearly see what they were doing. If you can imagine a physics experiment arranged on those optic tables with all the holes, with each element lined up and clamped in place - it was like that, but in miniature and without the holes. Each thing set up in line with the beam. Remember how long these heads are. If you wanted to have a demonstration to teach with, these would be excellent models. I was very impressed with the quality. All the other heads are compressed into much smaller volumes, and I think too small. They traded optics precision with size to some extent from what I have seen. The head could have been made smaller without giving the quality up, but that would mean a head slightly larger compared to an early Yamaha head, or a Sony KSS-123A for example. In modern heads, the various optical elements are sometimes in contact with each other. Too small.
The single beam system does not require a diffraction grating at all. It does require a beam splitter and / or prism, the same as a three beam setup does. The beam splitter deflects the returning beam to the pickup diodes and away from the laser diode. A mirror is just used to change the direction of a beam. The beam generally runs along the longest axis and is fired 90° up through the lens assemblies. I see in some heads they now just fire the beam straight up in line with the lens assemblies to do away with the mirror. That would be my guess anyhow.
-Chris
Yes, I couldn't resist the urge to see what was inside.
If I can find it, I'll post a picture. As I recall (clearly), each element of the optics was arranged in line so you could very clearly see what they were doing. If you can imagine a physics experiment arranged on those optic tables with all the holes, with each element lined up and clamped in place - it was like that, but in miniature and without the holes. Each thing set up in line with the beam. Remember how long these heads are. If you wanted to have a demonstration to teach with, these would be excellent models. I was very impressed with the quality. All the other heads are compressed into much smaller volumes, and I think too small. They traded optics precision with size to some extent from what I have seen. The head could have been made smaller without giving the quality up, but that would mean a head slightly larger compared to an early Yamaha head, or a Sony KSS-123A for example. In modern heads, the various optical elements are sometimes in contact with each other. Too small.
The single beam system does not require a diffraction grating at all. It does require a beam splitter and / or prism, the same as a three beam setup does. The beam splitter deflects the returning beam to the pickup diodes and away from the laser diode. A mirror is just used to change the direction of a beam. The beam generally runs along the longest axis and is fired 90° up through the lens assemblies. I see in some heads they now just fire the beam straight up in line with the lens assemblies to do away with the mirror. That would be my guess anyhow.
-Chris
Last edited:
"...let's build a quality cd player..."
audiostar: Unsure if your comment was meant sarcastically or not, but here are my thoughts on "...let's build a quality cd player...". I may never build any of this, a from scratch quality cd mechanism but I do have more than a passing interest. This whole thread addresses a pet peeve of mine, the relative "commoditization "of consumer goods. One of the first examples in electronics that I was involved with directly was the commoditization of television sets in the late 1980's and early 1990's. The margins got so low that it didn't matter what a manufacturer did or the quality of the sets. For example the very excellent Sony XBR series of televisions of that time, which were clearly superior to all others I was aware of or had any experience with. There may have been a few European makers (Lowe? Philips? ??) had good sets then, but most Japanese sets were not better, until Panasonic introduced the "Gao" sets, and JVC introduced the iART sets which could be argued about which was better. Because of mass discounting and lost leaders, the price of a colour television plummeted, and most never looked further than just the "advertised" price of a 27" tv. And so no good distinction existed between the better sets (as described with the previous examples) and the worst sets available at that time. The price of any television became a "standard" price with only a very few percent of margin in them, regardless of what quality they actually were. The consumers simply didn't differentiate between the different quality of sets and so the perceived value by the consumer was identical..
This has affected audio to a large degree. Every year it seems that the quality of the hifi equipment that is offered is deemed "good enough" and therefore suitable. I'd rather have to purchase used quality old stuff rather than new junk anytime.
As far as me building a cd player, a friend has done significant work on DACs and has good working examples of several types. The missing link is a good cd transport. If good transports were still available then there would most likely be no need for this thread.
audiostar: Unsure if your comment was meant sarcastically or not, but here are my thoughts on "...let's build a quality cd player...". I may never build any of this, a from scratch quality cd mechanism but I do have more than a passing interest. This whole thread addresses a pet peeve of mine, the relative "commoditization "of consumer goods. One of the first examples in electronics that I was involved with directly was the commoditization of television sets in the late 1980's and early 1990's. The margins got so low that it didn't matter what a manufacturer did or the quality of the sets. For example the very excellent Sony XBR series of televisions of that time, which were clearly superior to all others I was aware of or had any experience with. There may have been a few European makers (Lowe? Philips? ??) had good sets then, but most Japanese sets were not better, until Panasonic introduced the "Gao" sets, and JVC introduced the iART sets which could be argued about which was better. Because of mass discounting and lost leaders, the price of a colour television plummeted, and most never looked further than just the "advertised" price of a 27" tv. And so no good distinction existed between the better sets (as described with the previous examples) and the worst sets available at that time. The price of any television became a "standard" price with only a very few percent of margin in them, regardless of what quality they actually were. The consumers simply didn't differentiate between the different quality of sets and so the perceived value by the consumer was identical..
This has affected audio to a large degree. Every year it seems that the quality of the hifi equipment that is offered is deemed "good enough" and therefore suitable. I'd rather have to purchase used quality old stuff rather than new junk anytime.
As far as me building a cd player, a friend has done significant work on DACs and has good working examples of several types. The missing link is a good cd transport. If good transports were still available then there would most likely be no need for this thread.
Hi Stew,
Your thoughts echo my own. Currently, telephone systems are beginning that same process that gutted the audio industry. It doesn't help that inferior products are allowed to be advertised as better than the good stuff. Sound familiar? At the end of this pricing rainbow, there is that pot of ka-ka. Who always loses when items become a commodity? The consumer every single time. They just don't know it yet.
For sure there are very few good transports available for purchase. The ones that are good, are over-priced for what they are. Lots of marginal transports get good reviews and sell for a long dollar too.
I think that consumers lost faith in the audio industry (deserved) and gave up on quality. They've been lied to for years both at the distributor level, and the dealer level. I'm not surprised that many buy on price alone. Audio magazines have failed simply because of the garbage they print, like a soap opera in print. Consumers now have very low expectations and purchase mostly on price, sometimes considering brand as well. But the good days everyone enjoyed in the 70's and early 80's are dead and gone. The industry did it to itself. Yeah us!
One of the reasons I sold my service shop was that there was no longer anything to look forward to when the new service manuals came in. I used to look forward to them coming so I could see what was new, and order parts in advance that I knew we would need. It didn't pay to do that anymore, and the parts were 6 to 9 months away. Heck, the manuals now arrived 6 months after the new models were introduced! The next straw was that the shops now were charged for service manuals and were allowed to charge them back on the first service job on that model. Really? The deal was, we fix these new machines at reduced rates under warranty, the distributor gives the shops the service manuals and trains us on anything new. The warranty rates had remained the same for 6 to 8 years now, and they wanted to charge us for manuals while the products were more difficult to access - and do this in two weeks or less when they didn't have parts! Then some demanded we use their parts and charged a dollar minimum for each part. Even one resistor was a buck each, even in quantity. Yamaha was the worst for the parts demands. Oops, I named names. Don't worry, Yamaha wasn't alone in this. Did I mention that they didn't want to stock parts either?
Anyway, the situation became unbearable and by 1998, I was out of the business. Never felt better to be out from under that situation, yet I no longer was doing what I enjoyed to do. Many good shops closed as well. The big losers? The consumer - of course!
That about what you saw in the market Stew?
-Chris
Your thoughts echo my own. Currently, telephone systems are beginning that same process that gutted the audio industry. It doesn't help that inferior products are allowed to be advertised as better than the good stuff. Sound familiar? At the end of this pricing rainbow, there is that pot of ka-ka. Who always loses when items become a commodity? The consumer every single time. They just don't know it yet.
For sure there are very few good transports available for purchase. The ones that are good, are over-priced for what they are. Lots of marginal transports get good reviews and sell for a long dollar too.
I think that consumers lost faith in the audio industry (deserved) and gave up on quality. They've been lied to for years both at the distributor level, and the dealer level. I'm not surprised that many buy on price alone. Audio magazines have failed simply because of the garbage they print, like a soap opera in print. Consumers now have very low expectations and purchase mostly on price, sometimes considering brand as well. But the good days everyone enjoyed in the 70's and early 80's are dead and gone. The industry did it to itself. Yeah us!
One of the reasons I sold my service shop was that there was no longer anything to look forward to when the new service manuals came in. I used to look forward to them coming so I could see what was new, and order parts in advance that I knew we would need. It didn't pay to do that anymore, and the parts were 6 to 9 months away. Heck, the manuals now arrived 6 months after the new models were introduced! The next straw was that the shops now were charged for service manuals and were allowed to charge them back on the first service job on that model. Really? The deal was, we fix these new machines at reduced rates under warranty, the distributor gives the shops the service manuals and trains us on anything new. The warranty rates had remained the same for 6 to 8 years now, and they wanted to charge us for manuals while the products were more difficult to access - and do this in two weeks or less when they didn't have parts! Then some demanded we use their parts and charged a dollar minimum for each part. Even one resistor was a buck each, even in quantity. Yamaha was the worst for the parts demands. Oops, I named names. Don't worry, Yamaha wasn't alone in this. Did I mention that they didn't want to stock parts either?
Anyway, the situation became unbearable and by 1998, I was out of the business. Never felt better to be out from under that situation, yet I no longer was doing what I enjoyed to do. Many good shops closed as well. The big losers? The consumer - of course!
That about what you saw in the market Stew?
-Chris
Hi mlloyd1,
I service stuff now by myself. It's more enjoyable and I don't have to be part of the "rat race". I enjoyed running the business, but have zero intention of re-entering that market unless things change drastically. I can work from home now.
Because there are no margins anymore, all companies survive by charging where they can. Either they do that, or they aren't around next year. It's very simple. From what I have seen in the service world, there is a lot of overcharging going on for simple jobs. Its a mess out there. I have an acquaintance that is still running his shop since the mid 1990's I'd guess. He used to complete with me (I didn't compete with anyone, a waste of time). So, he isn't cheap, but he is one of the better shops out there. I send him people and wish the poor guy well.
-Chris
I service stuff now by myself. It's more enjoyable and I don't have to be part of the "rat race". I enjoyed running the business, but have zero intention of re-entering that market unless things change drastically. I can work from home now.
Because there are no margins anymore, all companies survive by charging where they can. Either they do that, or they aren't around next year. It's very simple. From what I have seen in the service world, there is a lot of overcharging going on for simple jobs. Its a mess out there. I have an acquaintance that is still running his shop since the mid 1990's I'd guess. He used to complete with me (I didn't compete with anyone, a waste of time). So, he isn't cheap, but he is one of the better shops out there. I send him people and wish the poor guy well.
-Chris
Hi Salar,
That can happen.
What I do is hook onto the service test points and since I know what to expect, I make the adjustment to optimize that signal. Things to set first are the VCO frequency, focus and tracking offsets, E-F balance then back to focus. Once those are done, hook up to the focus gain and adjust to the null between low and high frequency noise, then do the same thing for the tracking gain. Once done those, you do your fine adjustments on the offsets and fine adjust the E-F balance.
Too bad I'm not (a lot) closer to you. Give those instructions a whirl, but document the trimmer control positions before you start. A picture or pictures make an excellent memory device.
Good luck! -Chris
That can happen.
What I do is hook onto the service test points and since I know what to expect, I make the adjustment to optimize that signal. Things to set first are the VCO frequency, focus and tracking offsets, E-F balance then back to focus. Once those are done, hook up to the focus gain and adjust to the null between low and high frequency noise, then do the same thing for the tracking gain. Once done those, you do your fine adjustments on the offsets and fine adjust the E-F balance.
Too bad I'm not (a lot) closer to you. Give those instructions a whirl, but document the trimmer control positions before you start. A picture or pictures make an excellent memory device.
Good luck! -Chris
Good an valid points, but would the mechanism not be the same regardless of employment. The main goal must be to make a working mechanism then how it's put to use is the next step.
I have the capability to design the mechanical moving parts, but not to make the controls, select the best lens and to make that part of the system function.
hehe... Well didn't Kia or Hyundi or someone continue to make cars based on the Kadette MkII tooling for a decade or so after and sold quite well? How long has/was the original VW beetle made in countries around the world after it had long been out of production elsewhere?
If it were a Kadette Mk1 GTE then there would be many people interested in buying one.
But that's all moot because this is about producing something that is no longer made to a good quality any more. Cars ARE made to good quality and so are modern CPUs.
There is a large enough section of audio enthusiasts, including DIYers who are busy spending lots of money on rarer and rarer 80s/90s CD players because they want something with excellent build quality and pride of ownership. You don't get that with something that may work as well technically at reading a CD but which is flimsy and throw-away with no pride of ownership.
What this thread appears to lack (it may well be further back in the thread... sorry if it is) is a focus on who this transport would be for. Would it be for enthusiasts and DIYers? Or would it be for commercial implementation in commercial designs? The latter would mean a different focus and set of priorities.
For the right price, that is the ultimate "classic" ! It negates all the reliability problems of buying an old car but all the positives of the old design.
That is surely what we want here...
Is that for all mechs or were they all CDM9s perhaps?
I know that mech was used for quite a lot of top-loaders but also suffered from that problem as a mech. Common problem with some Naim CD players using it which aren't strickly speaking top loaders as the mech is embedded on a draw which closes, but still the user places the CD down onto the mech with a puck - just user error for some reason pushing down on the mech.
I would agree about the top-loader preferrence if you are aiming at the DIYer and not some commercial product. It is so much easier to implement in a DIY designed case,
For high-end commercial use, the slimline idea will probably be more sellable and desirable.
You're probably already aware of it but the tray constructed for the 90s B&O CD5500 is both elegant and looks simple (could be deceptive?).
NATDBERG,
Instead of questioning everyone, why not contribute something positive? The thread does have a focus and ideas are being actively pursued.
As for the disc table being pushed down, very rarely does that happen with a tray mechanism. Generally, it had been serviced and no locking compound was used in those cases. The big problem was always the top loading units.
BTW, B&O is delicate, heavy, under performing product best viewed through a window and not used. Service people don't like them for good reason.
-Chris
Instead of questioning everyone, why not contribute something positive? The thread does have a focus and ideas are being actively pursued.
As for the disc table being pushed down, very rarely does that happen with a tray mechanism. Generally, it had been serviced and no locking compound was used in those cases. The big problem was always the top loading units.
BTW, B&O is delicate, heavy, under performing product best viewed through a window and not used. Service people don't like them for good reason.
-Chris
You need to keep your attitude in check mate and calm the hell down - it's not appropriate for a DIY forum at all. You're really managing to turn this into a private thread by arguing and getting angry at other participants so that people turn away .
Is it me talking about the aim of the project you're angry about? It's not clear.
With a project like this, is it going to be a Group Buy for people on the forum or is it going to be designed here, private money put in and sold on the general market for OEM? Both have different requirements and lead you down different design paths. That should be obvious. If you're only interested in the excitement of designing a mech for yourself then expect to bare all of the costs yourself or someone to be out of pocket and ill feeling to result.
What is your CONTRUCTIVE criticism of the B&O tray mechanism? Do you have any? What were the specific problems with the tray? Or do you dismiss all design details simply because you don't like B&O in general?
The M Levinson 37 tray mech is another slim-line design to take into account - the way they do it makes it look very simple to contruct once the pieces are made up:
hifi-advice.com - CD Drawers and Transports - Mark Levinson
An externally hosted image should be here but it was not working when we last tested it.
Slim-line metal draw certainly the way to go in my mind if the mech is to be a commercial product for OEM use. Plastic ok if to be for DIYers who want to save money...
... of simple loading mechanisms and more ...
Guys:
we all need to lighten up a bit. If this projects comes to fruition, I believe the idea is to make it available as a group buy. I may or may not be able to participate depending on the final costs. For me that is a reality.
My suggestion for a top loader was to remove the complexity of a DIY tray mechanism. That's it.
I have an old Pioneer Elite PD-54 that worked the day I bought it (1990-ish) and continues to work today. It may have been a pretty cheap implementation of the "stable platter" mechanism, but was purchased for use in a dusty environment. To that end It has succeeded and has been completely issue free for at least the last 25 years.
Discussions regarding the details, such as a drawer mechanisms can take us a long way off track. But it will be required (by some ). I have no issues if a simple separately powered drawer mechanism is designed, with corresponding logic to control it (or even just a momentary "open"/"closed" switch). But the key is "separate". Or rather I suppose I should call it "modular". A modular approach would allow folks to buy specific portions of a "complete" transport. I know I can easily live without a drawer (I have used the old Sony "grey station" as a cd player to pretty good effect, and it uses a hinged lid). I also like Rega's solution with a top that includes a built in clamping mechanism.
As far as losing a clamp or having the magnets lose their strength, both are easy to overcome. I use wooden dowelling cut appropriately thin and glue miniature neo magnets to the thin dowelling. It works the charm and has significantly more strength than any of the mag-clamps I have seen.
Perhaps I am missing the point completely, but I believe that anatech's point is to create a top quality mechanism for those that are not happy with the mediocrity that has become to bear down upon cd transports. I know some folks on diyAudio.com have given up on cd as a medium. I haven't. Nor will I give up on my LPs. And I do have a music streamer (Logitech Squeezebox) that is OK but doesn't sound nearly as good as cd. Who knows, maybe I'll have to do something about that?
Again I believe that Anatech (and others) are just tired of the crap that we as consumers end up getting. Yes, could there exist a commercial opportunity? Perhaps, but the reality is that so few people seem to care, I don't think so.
Guys:
we all need to lighten up a bit. If this projects comes to fruition, I believe the idea is to make it available as a group buy. I may or may not be able to participate depending on the final costs. For me that is a reality.
My suggestion for a top loader was to remove the complexity of a DIY tray mechanism. That's it.
I have an old Pioneer Elite PD-54 that worked the day I bought it (1990-ish) and continues to work today. It may have been a pretty cheap implementation of the "stable platter" mechanism, but was purchased for use in a dusty environment. To that end It has succeeded and has been completely issue free for at least the last 25 years.
Discussions regarding the details, such as a drawer mechanisms can take us a long way off track. But it will be required (by some
). I have no issues if a simple separately powered drawer mechanism is designed, with corresponding logic to control it (or even just a momentary "open"/"closed" switch). But the key is "separate". Or rather I suppose I should call it "modular". A modular approach would allow folks to buy specific portions of a "complete" transport. I know I can easily live without a drawer (I have used the old Sony "grey station" as a cd player to pretty good effect, and it uses a hinged lid). I also like Rega's solution with a top that includes a built in clamping mechanism.As far as losing a clamp or having the magnets lose their strength, both are easy to overcome. I use wooden dowelling cut appropriately thin and glue miniature neo magnets to the thin dowelling. It works the charm and has significantly more strength than any of the mag-clamps I have seen.
Perhaps I am missing the point completely, but I believe that anatech's point is to create a top quality mechanism for those that are not happy with the mediocrity that has become to bear down upon cd transports. I know some folks on diyAudio.com have given up on cd as a medium. I haven't. Nor will I give up on my LPs. And I do have a music streamer (Logitech Squeezebox) that is OK but doesn't sound nearly as good as cd. Who knows, maybe I'll have to do something about that?
Again I believe that Anatech (and others) are just tired of the crap that we as consumers end up getting. Yes, could there exist a commercial opportunity? Perhaps, but the reality is that so few people seem to care, I don't think so.
Salar,
Similarly the CDP-XA20/30/50/55/555 which were all dedicated 'fixed pick-up' CD players, in this case with a pick and the whole mech. as a sliding drawer - probably the last of the 'high end' Sony units. I've several, one of which the British Postal Service dropped from a decent height and it survived (save the wrecked case). I've found that one slightly unusual advantage of a 'puck' system is that if a 'cold' player is reluctant to spin the disc (presumably because the pick-up doesn't focus), one can give it a little manual assistance by spinning the puck, which seems to encourage things.
I'll leave the innuendo to others! ;-)
Similarly the CDP-XA20/30/50/55/555 which were all dedicated 'fixed pick-up' CD players, in this case with a pick and the whole mech. as a sliding drawer - probably the last of the 'high end' Sony units. I've several, one of which the British Postal Service dropped from a decent height and it survived (save the wrecked case). I've found that one slightly unusual advantage of a 'puck' system is that if a 'cold' player is reluctant to spin the disc (presumably because the pick-up doesn't focus), one can give it a little manual assistance by spinning the puck, which seems to encourage things.
I'll leave the innuendo to others! ;-)