Hi All,
I've had recent problems with the laser for my Pioneer PD-91 CD Player and it got me thinking:
Lasers for old transports like mine are becoming harder and harder to find, with some models almost impossible to source any longer.
It would be a travesty to allow some of these players to die out because for the most part they are built and designed extremely well, (not to mention great sounding in their own way).
I know that for older gaming consoles there have been a number of successful recent implementations of 'Optical Drive Emulators' (Sega Saturn, Playstation etc..) allowing the user to replace the CD transport all together with a PCB board and hard-drive - this got me wondering of how hard it would be to implement something similar for vintage CD players.
The idea would be that this 'Emulation Board' could replace the CD transport with a SD Memory card or hard-drive and simulates the process of playing a CD allowing your player's DAC and output stage to still be put to good use.
Of course, this would be a shame for a lot of really well built transports (like in my Pioneer PD-91), however, in a world without suitable replacement lasers, what other options would you have to keep these players alive?
My hunch is that something like this must be possible, given that it works with gaming consoles (which have the added hurdle of anti-piracy protection)..
Thoughts?
Fish
I've had recent problems with the laser for my Pioneer PD-91 CD Player and it got me thinking:
Lasers for old transports like mine are becoming harder and harder to find, with some models almost impossible to source any longer.
It would be a travesty to allow some of these players to die out because for the most part they are built and designed extremely well, (not to mention great sounding in their own way).
I know that for older gaming consoles there have been a number of successful recent implementations of 'Optical Drive Emulators' (Sega Saturn, Playstation etc..) allowing the user to replace the CD transport all together with a PCB board and hard-drive - this got me wondering of how hard it would be to implement something similar for vintage CD players.
The idea would be that this 'Emulation Board' could replace the CD transport with a SD Memory card or hard-drive and simulates the process of playing a CD allowing your player's DAC and output stage to still be put to good use.
Of course, this would be a shame for a lot of really well built transports (like in my Pioneer PD-91), however, in a world without suitable replacement lasers, what other options would you have to keep these players alive?
My hunch is that something like this must be possible, given that it works with gaming consoles (which have the added hurdle of anti-piracy protection)..
Thoughts?
Fish
Very funny 
No, you would load ripped CDs into a folder structure onto the hard-drive. Essentially repurposing the player as a 44k/16bit media player/ DAC.
This idea would be similar to replacing the transport with a USB/Spdif input to use the DAC + output stage, with the addition of course of not needing to stream the music from another device.
I realise that many will say that you can simply just use another dac and forget the player all together. But the concept here is preserving the sound of these vintage players, of which some of them sound fantastic.
No, you would load ripped CDs into a folder structure onto the hard-drive. Essentially repurposing the player as a 44k/16bit media player/ DAC.
This idea would be similar to replacing the transport with a USB/Spdif input to use the DAC + output stage, with the addition of course of not needing to stream the music from another device.
I realise that many will say that you can simply just use another dac and forget the player all together. But the concept here is preserving the sound of these vintage players, of which some of them sound fantastic.
Correct - which is why this 'Transport Emulator' (for lack of a better name), needs to trick the player into believing it is the transport.
The current implementation of these devices (for game consoles) works in this way I believe. The device utilizes an FPGA chip and it 'replicates' the transport.
The current implementation of these devices (for game consoles) works in this way I believe. The device utilizes an FPGA chip and it 'replicates' the transport.
You might want to make contact with this group - Quality CD-Mechanisms are long gone - let us build one ourselves!. They seem up for a little old time religion.
The device itself would need a simple toggle switch to cycle between folder locations on the drive. Each folder would need to be a audio CD (set out like it would be on an actual CD). Every time you cycled through a folder, it would be read (TOC) like a normal CD and the CD players UI can do the rest.
Sure, but this concept isn't there to compete with the latest in digital streaming. There are of course much easier ways to simply play digital music. The options are very much mutually exclusive.
The concept is around reviving the use of the DAC and output stage of your CD player once the laser is dead and gone (and presumably can't be sourced).
The possibility came to me when I had seen what was happening with vintage game consoles. Personally owning a a 'high end' CD player from the early 90s (which I love the sound of), I'd love to have some options when the transport finally dies (because I know that replacement parts are becoming few and far between).
The concept is around reviving the use of the DAC and output stage of your CD player once the laser is dead and gone (and presumably can't be sourced).
The possibility came to me when I had seen what was happening with vintage game consoles. Personally owning a a 'high end' CD player from the early 90s (which I love the sound of), I'd love to have some options when the transport finally dies (because I know that replacement parts are becoming few and far between).
For me, because I have a collection of several hundred physical CDs, my objective with vintage CD players is to enjoy the complete experience of actually putting the disc into the tray and listening to it.
I agree there is a major issue with “unobtainium” mechanical transport parts such as laser optical pickups, motors, disc platters & clampers, plastic gears, pulleys, & slide assemblies. Also some IC chips often used in vintage CD players are now incredibly expensive because they haven’t been mass-produced in 20+ years (TDA1541A for example.)
My suggestion is to explore adapting a modern mass-produced CD transport mechanism to retrofit into existing CD players.
For example the KSS-213 style of CD transport is widely available at bargain prices:
KSS-213CCM Mechanism Pickup Optical Laser Lens Head Bloc Optique Optical Pickup | eBay
It is relatively small and because its chassis is a flat metal plate it should be fairly easy to fabricate mounting brackets to attach it to an existing tray assembly.
As for the electronic interface with an existing CD player, nearly all 3-beam optical pickups are (in theory) compatible with existing servo and RF preamplifier circuitry. It might be necessary to diy some level shifters and “glue logic” circuitry to install a different transport into an existing machine. Yet this would be a much smaller project in comparison to emulating a “virtual” disc transport mechanism.
-EB
Another aproach could be:
A databank of some kind, everytime you enter a "new" disk it will be stored, and played at the same time, now when offering the same disk again it will be "found" on the storage device and played back via the SSD or whatever you have. So the second time the transport is only used to read the TOC and then stops.
So you still have the feel of playing a CD but it is not played from the transport (only initially to copy it).
I had this idea already 15 years ago but never created a device like this.
A databank of some kind, everytime you enter a "new" disk it will be stored, and played at the same time, now when offering the same disk again it will be "found" on the storage device and played back via the SSD or whatever you have. So the second time the transport is only used to read the TOC and then stops.
So you still have the feel of playing a CD but it is not played from the transport (only initially to copy it).
I had this idea already 15 years ago but never created a device like this.
If you build something from scratch you can design it as you wish, the transport will not be used as much so will have a long life expectancy. The point will be that the feel of playing a CD is exactly the same. The user should not notice that there is a server or storage system used in the background. Sure you can use a Melco to do this. Can you set it up once and then forget it or do you still have menus to scroll and make choices if you want to play back from CD or server? if so it misses the point.
OK. Lets consider what it would take.
For starters, I take it no one would go bare metal, you need an SBC with SATA or a NUC. Either will need a decent amount GPIO to interface with the panel. I am assuming you interface with the audio at the digital filter as opposed to creating an eye pattern signal, good luck with that one if that is the case. Then there is the power supply.
Now where o where in the CD-100 do I fit all this new stuff ?
Meanwhile others are enjoying authentic early Philips sound having simply lifted the audio PCB out of a CD104 and stuck it in a box with multiple input options and a decent power supply.
For starters, I take it no one would go bare metal, you need an SBC with SATA or a NUC. Either will need a decent amount GPIO to interface with the panel. I am assuming you interface with the audio at the digital filter as opposed to creating an eye pattern signal, good luck with that one if that is the case. Then there is the power supply.
Now where o where in the CD-100 do I fit all this new stuff ?
Meanwhile others are enjoying authentic early Philips sound having simply lifted the audio PCB out of a CD104 and stuck it in a box with multiple input options and a decent power supply.
OK, I see were missing a point here. The fact is, that many CD Players as the OP said have unobtanium laser heads (I for one, own a Sony CDP X 707ES with Unobtanium kss-272a head). Now, as much as I really enjoy placing those CD in that smooth tray, and considering this is a 900Euro player (some Swoboda units easily reach 1500 Euro in the used market in Germany), ensuring it can also work with an emulator would be great. And the emulator could have its own UI, using a Raspberry Pi could get you what you want but nice polished interfaces are a follow up!
The concept is incredibly interesting, and all it has to do is emulate a laser head which is a handful of parts. Even the actual mechanism itself could be preserved. Tray opening/closing, track selection, complete UI of the CD working...
I am not an engineer, but if the guys did it with a console - maybe it can be done with an audio CD. And since almost ALL cd transport use the SAME principle, two motors to move the head and turn the CD, two coils to focus the lens, and the laser itself, it should be possible to configure the outputs and inputs of the emulator for a lot of different CD players. Remember, you dont have to work on the complexities of the player logic itself, but only on the very simple commands the control IC is sending and receiving from the mechanical transport: simple switches signaling tray closed, end position of the laser pickup, etc; tracking focus etc can all be ignored since the signal from the emulated laser would be always perfect.
I think it is doable
The concept is incredibly interesting, and all it has to do is emulate a laser head which is a handful of parts. Even the actual mechanism itself could be preserved. Tray opening/closing, track selection, complete UI of the CD working...
I am not an engineer, but if the guys did it with a console - maybe it can be done with an audio CD. And since almost ALL cd transport use the SAME principle, two motors to move the head and turn the CD, two coils to focus the lens, and the laser itself, it should be possible to configure the outputs and inputs of the emulator for a lot of different CD players. Remember, you dont have to work on the complexities of the player logic itself, but only on the very simple commands the control IC is sending and receiving from the mechanical transport: simple switches signaling tray closed, end position of the laser pickup, etc; tracking focus etc can all be ignored since the signal from the emulated laser would be always perfect.
I think it is doable
Creating the RF pattern is really what should be done, as it is the only constant in basically all CD players, and abstracts the emulator from all the plethora of different protocols, functions, UI etc in the generations of CD players of the last 40 years. It can be done as it is the result of the VCO modulated by the reflection of the laser from the pits and lands on the CD. It can be emulated using the raw bit stream of a WAV file.
Space? it's all solid state and built in SMD can be REALLY small.