Alternatives to IDE Digital???
Hello everyone.
I know NOTHING about all this sort of thing, but I have been quietly following this thread.
This thread is about "digital audio from IDE", but what are the alternatives to this option?
Do most of you who make their own DAC's just buy a real cheapie DVD player and use this as a transport or is there another solution using CD-ROM drives??
Regards,
George.
Hello everyone.
I know NOTHING about all this sort of thing, but I have been quietly following this thread.
This thread is about "digital audio from IDE", but what are the alternatives to this option?
Do most of you who make their own DAC's just buy a real cheapie DVD player and use this as a transport or is there another solution using CD-ROM drives??
Regards,
George.
The project that woul dhave been built here is a processor reading the CD with digital audio extraction and output a jitter-free I2S signal. If ever created, it would probably be able to play formats like MP3, OGG, AAC, etc. also.
Re: Alternatives to IDE Digital???
transports are all inferior to using a computer to rip bit-perfect copies from cds, then playing back from a computer (whether a pc or something like a squeezebox).
bb
GeorgeBoles said:
transports are all inferior to using a computer to rip bit-perfect copies from cds, then playing back from a computer (whether a pc or something like a squeezebox).
bb
More info please, Dragon Master.
Hello Dragon Master,
Given that this project is huge and unfinished, what is everybody doing at the moment if they have a beautiful Do-It-Yourself DAC in their system?
b-square,
I certainly have not yet heard a computer playing off its hard drive sound all that good. I thought that the overall plan was to get the high quality DAC out of the computer case and place it some distance from the computer's digital hash.
Also, what you describe would mean that whenever I wanted to play a CD, I would have to rip it first, re-join any tracks which require playing with no gap, and then playing them back from a wretched computer, with its boot up time, crumby keyboard, mouse, etcetera. That would, I think, take longer than taking an LP out of its cover after you have washed the sweat and oil off your hands, cleaning the LP, cleaning the styluse and then lining up the needle on the start up groove 😉 ... I want to turn on my hifi, pop in a CD, settle back and enjoy.
Regards,
George.
Hello Dragon Master,
Given that this project is huge and unfinished, what is everybody doing at the moment if they have a beautiful Do-It-Yourself DAC in their system?
b-square,
I certainly have not yet heard a computer playing off its hard drive sound all that good. I thought that the overall plan was to get the high quality DAC out of the computer case and place it some distance from the computer's digital hash.
Also, what you describe would mean that whenever I wanted to play a CD, I would have to rip it first, re-join any tracks which require playing with no gap, and then playing them back from a wretched computer, with its boot up time, crumby keyboard, mouse, etcetera. That would, I think, take longer than taking an LP out of its cover after you have washed the sweat and oil off your hands, cleaning the LP, cleaning the styluse and then lining up the needle on the start up groove 😉 ... I want to turn on my hifi, pop in a CD, settle back and enjoy.
Regards,
George.
George,
I think you've hit the nail on the head in regards to what we proposed to do. We want to take the bit perfect capability of a cd-rom drive through the IDE interface, but without the entire computer that surrounds it.
In a previous post, I pointed out the Creek cd50mk2 as our target, as I believe that, or at least the transport portion, is exactly what we are trying to produce.
Unfortunately, we are at a crossroads in this project, and don't really have a plan to move forwards.
The two approaches that have been laid out are these:
1) embedded linux (ucLinux) operating the IDE device. This would allow porting of various Linux programs which would enable bit perfect reading of the data.
2) Custom micro code based on the various IDE specifications.
The challenge in the first scenario is fitting all the code required into firmware without blowing up the system requirements.
The challenge to the second is the limited pool of people capable of writing the micro code.
In either case, GMarsh has made the most progress in putting forward hardware ideas based on the AD Blackfin processor, which could run either the ucLinux or custom code.
I believe there is a significant amount of interest in this, if purely academic, however, the costs associated with this project look like the may be pretty substantial, and may not suit most people as a DIY project.
Can this be done? Absolutely. Can it be accomplished for less than the cost of the Creek cd50mk2? Possibly not. If it can't be done for less cost than a commercial unit, is it worth doing outside of academic curiosity?
- Ken
I think you've hit the nail on the head in regards to what we proposed to do. We want to take the bit perfect capability of a cd-rom drive through the IDE interface, but without the entire computer that surrounds it.
In a previous post, I pointed out the Creek cd50mk2 as our target, as I believe that, or at least the transport portion, is exactly what we are trying to produce.
Unfortunately, we are at a crossroads in this project, and don't really have a plan to move forwards.
The two approaches that have been laid out are these:
1) embedded linux (ucLinux) operating the IDE device. This would allow porting of various Linux programs which would enable bit perfect reading of the data.
2) Custom micro code based on the various IDE specifications.
The challenge in the first scenario is fitting all the code required into firmware without blowing up the system requirements.
The challenge to the second is the limited pool of people capable of writing the micro code.
In either case, GMarsh has made the most progress in putting forward hardware ideas based on the AD Blackfin processor, which could run either the ucLinux or custom code.
I believe there is a significant amount of interest in this, if purely academic, however, the costs associated with this project look like the may be pretty substantial, and may not suit most people as a DIY project.
Can this be done? Absolutely. Can it be accomplished for less than the cost of the Creek cd50mk2? Possibly not. If it can't be done for less cost than a commercial unit, is it worth doing outside of academic curiosity?
- Ken
Re: More info please, Dragon Master.
That's what the SqueezeBox is for, and b-square mentioned it. The SqueezeBox receives music from the PC, and then acts as a source. You can use either its own internal DAC, or one of the two S/PDIF outputs. It makes the CD player seem quaint in comparison.
GeorgeBoles said:
That's what the SqueezeBox is for, and b-square mentioned it. The SqueezeBox receives music from the PC, and then acts as a source. You can use either its own internal DAC, or one of the two S/PDIF outputs. It makes the CD player seem quaint in comparison.
Re: Re: More info please, Dragon Master.
The Squeeze Box is a partial solution. It gets the DAC out of the computer case, which is good. But it is connected by either Wi-Fi (which to a careful listener noticeably degrades the sound of any stereo) or ethernet (which couples the electrical noise of the computer to the stereo). One way around this is to use TosLink to electrically isolate an external DAC, but this adds quite a large amount of jitter.
It still doesn't address any of the usability issues raised by GeorgeBoles.
ezkcdude said:
The Squeeze Box is a partial solution. It gets the DAC out of the computer case, which is good. But it is connected by either Wi-Fi (which to a careful listener noticeably degrades the sound of any stereo) or ethernet (which couples the electrical noise of the computer to the stereo). One way around this is to use TosLink to electrically isolate an external DAC, but this adds quite a large amount of jitter.
It still doesn't address any of the usability issues raised by GeorgeBoles.
Hello I'm new in this comunity and was also thinking about building a CD-Player with a CD-Rom drive.
Wouldn't it be much easier to take the digital out from the cd-rom and connect it to an DA?
The IDE could be used by a ATMEL (ATMEGA XXX?) to control the "Player" and get the Informations that should be displayed on a LCD.
Otherwise I'm not very happy with the quality of the CD-Rom Drives if I look to the stable Drive of my Mission DAD5 (Philips CDM9) or my Pioneer PD-73 with his linearmotor for the Head.
But the "dark" site of this drives is that they were'nt available after a couple of years, like the CDM9 or the Laser costs as much as a new Player.
In this case the CD-Rom drive is the better choice because if it's laser ist broken you buy a new CD-Rom and change it with the one in your DIY Player.
The third cheap way ist to build a player form an old PS1 Modell SCPH1002 but there is no ability to get Display Informations without taking 2-4" TFT Displays.
But back to the common questione...why do you think the sound would be better when you take the informations from the IDE instead from the digital out?
The Error Correction will be activ in both cases, wouldn't it?
Sorry for my bad english...it's only from school and that is far, far away...
Regards
Cobra71
Wouldn't it be much easier to take the digital out from the cd-rom and connect it to an DA?
The IDE could be used by a ATMEL (ATMEGA XXX?) to control the "Player" and get the Informations that should be displayed on a LCD.
Otherwise I'm not very happy with the quality of the CD-Rom Drives if I look to the stable Drive of my Mission DAD5 (Philips CDM9) or my Pioneer PD-73 with his linearmotor for the Head.
But the "dark" site of this drives is that they were'nt available after a couple of years, like the CDM9 or the Laser costs as much as a new Player.
In this case the CD-Rom drive is the better choice because if it's laser ist broken you buy a new CD-Rom and change it with the one in your DIY Player.
The third cheap way ist to build a player form an old PS1 Modell SCPH1002 but there is no ability to get Display Informations without taking 2-4" TFT Displays.
But back to the common questione...why do you think the sound would be better when you take the informations from the IDE instead from the digital out?
The Error Correction will be activ in both cases, wouldn't it?
Sorry for my bad english...it's only from school and that is far, far away...
Regards
Cobra71
Re: Re: Re: More info please, Dragon Master.
Huh? Are you talking about waiting for the computer to boot? I leave mine on all the time. It takes much longer for my amp to warm up properly, and I certainly don't want to leave that on all the time, anyway. With the SqueezeBox, you never have to get up to change CD's either. Not only that, but you can listen to anything you want in your collection without having to dig around for it. Add a "smart" randomizing program like MusicMagic (which is just awesome), and you cannot beat the listening experience and convenience of the SqueezeBox. Believe me, I didn't realize how much it would change the way I listen to music. No CD players for me ever again!
Charles Hansen said:
Huh? Are you talking about waiting for the computer to boot? I leave mine on all the time. It takes much longer for my amp to warm up properly, and I certainly don't want to leave that on all the time, anyway. With the SqueezeBox, you never have to get up to change CD's either. Not only that, but you can listen to anything you want in your collection without having to dig around for it. Add a "smart" randomizing program like MusicMagic (which is just awesome), and you cannot beat the listening experience and convenience of the SqueezeBox. Believe me, I didn't realize how much it would change the way I listen to music. No CD players for me ever again!
Re: More info please, Dragon Master.
yes, you'd have to rip it first, but for the rest you are way off target. use a squeezebox, you'll understand.
bb
GeorgeBoles said:
yes, you'd have to rip it first, but for the rest you are way off target. use a squeezebox, you'll understand.
bb
Re: Re: Re: More info please, Dragon Master.
the most important piece is the bit-perfect ripping, which is something you simply cannot duplicate with _any_ transport that plays back in real time. i'll leave the rest of your speculation alone.
bb
Charles Hansen said:
the most important piece is the bit-perfect ripping, which is something you simply cannot duplicate with _any_ transport that plays back in real time. i'll leave the rest of your speculation alone.
bb
as a thought exercise, consider whether there is more or less interference, of whatever sort, from the power supply and activity of a minimum 4200rpm ide drive, vs. an ethernet connection from a switch.
Cobra71 said:
Error correction is not turned on when using the rom drive in CD-playback mode. In that mode, you get whatever stream the drive is able to produce, complete with whatever read errors and timing errors are introduced by the physical drive.
By using the IDE interface, we can control the drive more accurately, and even utilize 4x or higher spin rates to read the same block multiple times ensuring that we get the correct bits from disc.
- Ken
Re: Re: Re: Re: More info please, Dragon Master.
Why do you say this? A real-time audio CD player can perfectly correct virtually all errors using the CIRC error correction code. Some errors due to large scratches are uncorrectable, but reading the disc multiple times with a ROM drive won't generally produce better results.
b-square said:
Why do you say this? A real-time audio CD player can perfectly correct virtually all errors using the CIRC error correction code. Some errors due to large scratches are uncorrectable, but reading the disc multiple times with a ROM drive won't generally produce better results.
tsai said:
This is not true. The CIRC error correction is always active. Virtually all common errors are fully corrected.
tsai said:
First of all, what do you mean by "control the drive more accurately"? This makes no sense. Please spend a some time with a nice little document that explains all of this:
http://www.t10.org/ftp/t10/drafts/mmc2/mmc2r11a.pdf
and you will have a better understanding.
Multiple reads have questionable value. The only reason to even think about multiple reads is if there are errors uncorrectable by CIRC. This almost never happens unless there is a huge gouge in your disc. Please refer to the following Stereophile article for more information on this:
http://stereophile.com/reference/590jitter/
Here is a relevant excerpt, "in all the hours of error-rate measuring for this project, I never encountered an E23 error, the first and most sensitive indication of an interpolation (except on the Pierre Verany disc, which has intentional errors [created by physically damaging the aluminum layer with calibrated gaps]). In fact, I saw only one E22 error, the last stage of correction before concealment. In retesting the disc, the E22 error disappeared, indicating it was probably due to a piece of dirt on the disc."
And if you did have a huge gap that created an error uncorrectable by CIRC, why do you think the reading it multiple times would improve the situation?
b-square said:
There are at least two flaws in your reasoning:
1) Just because there is some electrical noise already in the system doesn't mean that it's a good idea to add more noise.
2) The noise from the ethernet connection isn't just the ethernet signal. It also includes:
a) The switching power supply of the computer.
b) The CPU clock.
c) The memory clock.
d) Other various clocks on peripherals, including the real-time clock, clocks inside the optical drives, clocks on the video card, clocks in the hard drive, et cetera, et cetera.
e) The switching power supply in the video monitor.
f) Et cetera.
Multiple speed reading of the disk will produce multiple noise too and you have also to buffer the informations on the disk instead playing it in realtime like a real CD-PLayer.
If I think about Hifi than I think about Turntables and CD-PLayers and REAL Hifi Amps but not on a PC-based Sound reproducing machine or Dolby digital Receivers.
Thats my opinion...
Cobra71
If I think about Hifi than I think about Turntables and CD-PLayers and REAL Hifi Amps but not on a PC-based Sound reproducing machine or Dolby digital Receivers.
Thats my opinion...
Cobra71
Charles Hansen said:
Interesting food for thought. I'll have to go read those papers when I have more time. To be honest, I haven't done as much research on the cd drive mechanism as I should. Shame on me.
I do know, based on listening, that the digital stream produced by the cd drive in playback mode is terrible. This may be just a clock issue. I assumed it was more than a clock issue, and when I ran accross this thread, it seemed others had also put thought into this problem. Some of my statements above are just parroting what others have said in this thread earlier. Again, shame on me for taking everything at face value instead of doing my own research.
Thanks for the links, Charles!
- Ken
Charles Hansen said:
the choice i was offering was between 2 different noise sources: a hard drive vs. an ethernet connection. i don't see where i suggested adding more noise as a good idea. also not addressed by your comments is the issue of mechanical vibration from a hard drive.
Charles Hansen said:
you seem to be assuming a configuration that i neither use nor have advocated: the squeezebox (or similar) connected directly to the server streaming the music. as i said, there is a switch in between. that switch has a significantly smaller power supply then a pc and a conspicuous lack of most of the peripherals you mention. could noise leak through? certainly, but i'd have to see real measurements of that before i believe it represents a more audible impact than, say, my neighbor's wireless network, which i also can't hear because i am cursed with these terrible ears, but which you've said repeatedly must be having a huge, negative effect on the sound quality.
bb
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