All,
A few years ago when I was looking on here there were a million people who were making some rather groovy CD transports based on the CDMPro2.
I won't pretend that the CDMPro2 for me took away half of the fun of making a CD transport which was the electronics bit, so I never got on board. But since the demise of the module, I'm surprised that some of the skilled people on here have not come up with a pairing of a mech and developed their own controller board for it.
There are a couple of ways this could be done - find a mech and reverse engineer the circuit diagram to control it from a device it is used in, or, simply build the circuit from scratch. The mech controller devices are now so integrated that it looks to be a one chip solution. Perhaps in the older days of CDs this would have been slightly trickier. Some recent ones even have MP3 decoders built in!
With a CDMPro2 costing around £300 at the time and a modern DVD mech costing around 20, I think the cost of putting such a unit together with a board would be comparable.
I know for a while CD-ROM based units sprang up but the switch to SATA has put that to bed for most things, but after around 2005 absolutely nothing has surfaced! Is it just that people prefer modding the older stuff now? I'd be interested to hear since I suspect that a lot of people on here seem to be capable of this.
A few years ago when I was looking on here there were a million people who were making some rather groovy CD transports based on the CDMPro2.
I won't pretend that the CDMPro2 for me took away half of the fun of making a CD transport which was the electronics bit, so I never got on board. But since the demise of the module, I'm surprised that some of the skilled people on here have not come up with a pairing of a mech and developed their own controller board for it.
There are a couple of ways this could be done - find a mech and reverse engineer the circuit diagram to control it from a device it is used in, or, simply build the circuit from scratch. The mech controller devices are now so integrated that it looks to be a one chip solution. Perhaps in the older days of CDs this would have been slightly trickier. Some recent ones even have MP3 decoders built in!
With a CDMPro2 costing around £300 at the time and a modern DVD mech costing around 20, I think the cost of putting such a unit together with a board would be comparable.
I know for a while CD-ROM based units sprang up but the switch to SATA has put that to bed for most things, but after around 2005 absolutely nothing has surfaced! Is it just that people prefer modding the older stuff now? I'd be interested to hear since I suspect that a lot of people on here seem to be capable of this.
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It seems no one is interested in building their own CD transports anymore!
It seems no one is interested in building their own CD transports anymore!
I used the Advanced Search in Digital Source, "transport" in title only, and found some relevant hits:
Finally, an affordable CD Transport: the Shigaclone story
So who wants a CD transport?
How to convert a DVD Drive into a transport to feed a DAC?
HIFIDIY CD Transport Kit
CDPRO2 Group Project (open source project)
Finally, an affordable CD Transport: the Shigaclone story
So who wants a CD transport?
How to convert a DVD Drive into a transport to feed a DAC?
HIFIDIY CD Transport Kit
CDPRO2 Group Project (open source project)
I've seen these - those are the threads that are essentially dead or based on dead hardware. I've even posted on a few. The CDPro has been out of production for ages! CD Rom drives are largely a cheat but interesting.
Like I say, I just felt a DIY CDPro replacement was achievable with some of the super technical skills on here.
New CD Transports
I think the main problem is the lack of interest from the general public in CD's anymore. So the major manufacturers are not making any new hardware for the format.
Therefore any DIY project has to be using old technology. So, second hand equipment has to be used as a source of parts.
Sorry if this is already what you know.
I for one love CD's.
I've been fixing them ever since they were introduced. I was fortunate enough to be studying at the time when they came out and a chap from SONY came to the college to explain its workings.
Just from an engineering point of view, the way the 1's and 0's are extracted from the silver disc is fascinating and then the maths involved to retrieve th analogue signal, again, to me so interesting. I'd love a chat with some of the early pioneers from Philips and SONY.
With what I said about old technology I decided I'd use a Philips CDM-1 as my starting block for my project which then used the electronics from a later Philips unit to give the control and processing.
I've ended up with a Transport with SPDIF and i2S out which works quite well.
It has a few little quirks not wanting to play some discs (which I can visually see no faults with) but on the whole it plays well and sounds great.
It's not 100% perfect and requires a donor machine so I wouldn't feel happy offering this as a project for others.
But here's what I came up with.
Case from eBay.
I think the main problem is the lack of interest from the general public in CD's anymore. So the major manufacturers are not making any new hardware for the format.
Therefore any DIY project has to be using old technology. So, second hand equipment has to be used as a source of parts.
Sorry if this is already what you know.
I for one love CD's.
I've been fixing them ever since they were introduced. I was fortunate enough to be studying at the time when they came out and a chap from SONY came to the college to explain its workings.
Just from an engineering point of view, the way the 1's and 0's are extracted from the silver disc is fascinating and then the maths involved to retrieve th analogue signal, again, to me so interesting. I'd love a chat with some of the early pioneers from Philips and SONY.
With what I said about old technology I decided I'd use a Philips CDM-1 as my starting block for my project which then used the electronics from a later Philips unit to give the control and processing.
I've ended up with a Transport with SPDIF and i2S out which works quite well.
It has a few little quirks not wanting to play some discs (which I can visually see no faults with) but on the whole it plays well and sounds great.
It's not 100% perfect and requires a donor machine so I wouldn't feel happy offering this as a project for others.
But here's what I came up with.
Case from eBay.
Attachments
Now that's the sort of thing! However the control circuitry for these old mechs is similar to the new ones. There are a few minor differences between some of the wiring between brands but that knowledge is widely known on here (not by me but I've followed the descriptions enough to understand).
I disagree with you - I think if you publish your design, you'd get people doing what they always do and suggesting what might be going wrong to come up with the ultimate design, pointing out which power supplies are sensitive, which are relaxed. You have exactly the sort of system where that begins! That CD controller PCB can then find its way into the DIYaudio shoppe!
I disagree with you - I think if you publish your design, you'd get people doing what they always do and suggesting what might be going wrong to come up with the ultimate design, pointing out which power supplies are sensitive, which are relaxed. You have exactly the sort of system where that begins! That CD controller PCB can then find its way into the DIYaudio shoppe!
The thing with my 'design' though, is it's not MY design. It's a Philips design and all I did was to design PCB's for the schematic which fitted into the case I had chosen.
I wanted to use the CDM-1 because they're such a good well-built Laser mech and seem to go on forever, I've yet to see a worn out one, in 31 years of Hi-Fi servicing, the only faulty ones I've seen have been caused by a bad enginner or an end user 'having a go'.
I tested the concept that it could work with a CDM-2 RF Amp PCB, it did, so I then set about drawing the PCB's out to fit in the casework.
It's not really my design to publish.
Also the IC's needed are no longer in production, I just used an old player so this could not be made unless just the right player could be found.
It's not really a repeatable project I don't think. If one of the control IC's fails I will have to find yet another donor player and rob the chip from it. They're not available off the shelf anymore.
No-one seems to be making off the shelf control units anymore. (I want to be proved wrong here). And if they are I doubt they'd be useable with an old Philips Laser.
That's not to say that the new Laser wouldn't be any good but I doubt it would be as long lasting !!
I wanted to use the CDM-1 because they're such a good well-built Laser mech and seem to go on forever, I've yet to see a worn out one, in 31 years of Hi-Fi servicing, the only faulty ones I've seen have been caused by a bad enginner or an end user 'having a go'.
I tested the concept that it could work with a CDM-2 RF Amp PCB, it did, so I then set about drawing the PCB's out to fit in the casework.
It's not really my design to publish.
Also the IC's needed are no longer in production, I just used an old player so this could not be made unless just the right player could be found.
It's not really a repeatable project I don't think. If one of the control IC's fails I will have to find yet another donor player and rob the chip from it. They're not available off the shelf anymore.
No-one seems to be making off the shelf control units anymore. (I want to be proved wrong here). And if they are I doubt they'd be useable with an old Philips Laser.
That's not to say that the new Laser wouldn't be any good but I doubt it would be as long lasting !!
I think that's enough - a reference design gets people started. It means someone can write the micro software to generate a control interface, it means that you can work on skipping, fast forwarding and soforth without the need for any hardware design at all. Then you can use the working controller to try make it work with the sony mechs and other philips mechs. They all look to have the same driver circuitry to me.
Above all it might just answer enough questions to enthuse other people to get started. It certainly has for me! I think I'm going to do something with this when I get my power supply curiosity sorted.
Above all it might just answer enough questions to enthuse other people to get started. It certainly has for me! I think I'm going to do something with this when I get my power supply curiosity sorted.
I just picked up an Oppo BDP-103D for AU$450.00 so why would I build one? Last time I went that route I spent $30,000 on parts and licensing to Pacific Microsonics for an HDCD DAC. The source material was so scarce in Australia that I had to abandon it, then Microsoft bought them out. No thanks.
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It sounds like DIY audio is not for you then! Off the shelf audio is available to everyone. Some of us just like doing more. Curious why you went down the route of a dead format though...
All the non-CD Players I have listened to don't sound anywhere near as good as a dedicated CD Player, playing CD's.
Modern CD Players using DVD Mechanisms also, to me don't sound as good as a dedicated CD Player.
HDCD sounded great though.
I have never looked into it far enough to understand what they were doing and why it sounded so good, but to me, it did.
Oh quite right, HDCD and the PMD100 chip were great. But if we're honest, there was so little media for it that it wouldn't be worth licensing (or licencing?) the IP for the DSP implementation which is how I believe it is now sold (if it's still available now), even at 2 dollars a chip royalty! I think 3 of my xxxxxx discs are HDCD.
I don't remember exactly the numbers but vaguely on the disc the 16 bit data is split into 2 8 bit sections and each of the 8 bits are stored separately in a 14 (I think - this is old memory!) bit space on the disc where those extra bits are used for other stuff (maybe error correction info, maybe nothing). If you scrap some of that data you effectively have more bits to store data. Then, since the original 8 bits remains intact, it still plays on normal players. Probably a bit more magic than that but for two lines I think that will do!
Whilst I agree CD is a dying format, until there are more high quality, non child oriented streaming services which can fully replace the disc artwork etc, it will linger around in high end audio. After all, Naim didn't even build their first CD spinner until the 90s!
Just seen a dud MCD Pro go for £412 on ebay. Seems to me the electronics are the least of the problems.
For almost a decade I am seeking to build a transport from scratch.
I did measure and digititise the Sony BU-1 into CAD besides the guts.
I am not an engineer and asked many times in this forum to join to do the math needed:
Optical calculations, reverse engineering of the 80´s circuits, designing the coils etc.
No copyright infrightment to be feared, as patents have run out for more than 10 years.
But no one joined so far.
Also the side-project for at least replacing the laser diodes is pending fo almost 18 months now...
I did measure and digititise the Sony BU-1 into CAD besides the guts.
I am not an engineer and asked many times in this forum to join to do the math needed:
Optical calculations, reverse engineering of the 80´s circuits, designing the coils etc.
No copyright infrightment to be feared, as patents have run out for more than 10 years.
But no one joined so far.
Also the side-project for at least replacing the laser diodes is pending fo almost 18 months now...
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I was very interested in your thread because spinning discs is how I listen the majority of the time. However, they are usually greater than 16 bit and greater than 48kHz. I think that is a major issue with the popularity of your initiative, even forgetting the competition from memory-based and streaming sources.
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Salar, thanks for your comments. I think what you have just said shows the massive misunderstanding about these designs. As the years have progressed, all of that stuff has now been so integrated that the actual controller is just one chip. I suppose the complexity would come in the PIC or ARM that drives that chip to do track forward/back etc.
From what I can see, when you buy a module, it is delivered working! There is no calibration or coil design or anything. And they all look to be somewhat standardised, even between models. That may not be true for quite everything, but it makes sense that what I percieve to be true is actually true based on a manufacturer being able to sell a CD player for a tenner (not very much money!) these days.
It's all off the shelf - take a look at the On Semiconductor LC78615 which is £2.92 ea in multiples of 1 off and has 295 in stock at Mouser! I think you need the mech and a servo drive to make that a configured unit. (I am guessing the 78615 is actually an old Fairchild part). This is also a recent product in active production. All of the non integrated chips such as those on your Sony schematic on your other thread are all LONG out of production. Perhaps we need to crack open a CD player.
Leadbelly - what on earth are you going on about. I haven't actually bought a CD in about 8 years but I have hundreds that I bought in the 90s and early 00s. A quick look on Amazon tells me that a good handful of the most popular, multi-platinum titles are still only available on CD. What sort of obscure rubbish are you listening to just because its in some novel hi-res format which... as far as I am concerned has never been standardised! There is no defacto hi-res disc format! From what I see, they all failed!
From what I can see, when you buy a module, it is delivered working! There is no calibration or coil design or anything. And they all look to be somewhat standardised, even between models. That may not be true for quite everything, but it makes sense that what I percieve to be true is actually true based on a manufacturer being able to sell a CD player for a tenner (not very much money!) these days.
It's all off the shelf - take a look at the On Semiconductor LC78615 which is £2.92 ea in multiples of 1 off and has 295 in stock at Mouser! I think you need the mech and a servo drive to make that a configured unit. (I am guessing the 78615 is actually an old Fairchild part). This is also a recent product in active production. All of the non integrated chips such as those on your Sony schematic on your other thread are all LONG out of production. Perhaps we need to crack open a CD player.
Leadbelly - what on earth are you going on about. I haven't actually bought a CD in about 8 years but I have hundreds that I bought in the 90s and early 00s. A quick look on Amazon tells me that a good handful of the most popular, multi-platinum titles are still only available on CD. What sort of obscure rubbish are you listening to just because its in some novel hi-res format which... as far as I am concerned has never been standardised! There is no defacto hi-res disc format! From what I see, they all failed!
I stand corrected - I found a Metallica disc in DVD audio format for £120 (I didn't really check but the CD was less than a tenner).
I'm not trying to be controversial or cause an argument, I just think what you're saying is nonsense unless you buy the format rather than the music on it.
Glad you've got an open mind in that cave.
I did try to find a resource that would list SACD by release date, but I couldn't. This is the closest I could get:
CDJapan : Music
High Fidelity CD Format
SACD /
Complete List of April 2020 Releases
CDJapan : Music
High Fidelity CD Format
SACD /
Complete List of March 2020 Releases
CDJapan : Music
High Fidelity CD Format
SACD /
Complete List of February 2020 Releases
CDJapan : Music
High Fidelity CD Format
SACD /
Complete List of January 2020 Releases
CDJapan : Music
High Fidelity CD Format
SACD /
Complete List of December 2019 Releases
etc.
EDIT: this sorts by release, and has more popular music. It doesn't have dates, but the T. Rex was released Apr 24, 2020:
http://elusivedisc.com/music/digital/sacd/#/sort:ss_days_since_released:asc
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