A few years ago I wondered about that and re-ripped a few burned CDs, there were no read errors, even with a reasonable amount of scratches. Interleaved Reed & Solomon FTW !
IMO there are two mechanisms :
- Placebo effect obviously
- The fact that many so called high end CD players are not so well designed, and you can get coupling between various stuff inside, for example the laser pickup tracking actuator solenoids draw a lot of current as they move the lens to follow the track, and this current depends on vibration and track shape, it can be different between various CDs. I remember this particularly crappy player, a CD723, where just walking in the room would make the power supply wobble on the scope, as the pickup servo compensated for the vibrations. This player was a pretty good microphone.
Also, often you have a big LSI chip handling everything (all the decoding etc) and it outputs I2S to the DAC, and the clock is in the wrong place, for example the clock goes through the decoder chip instead of being in the correct place (2cm away from the DAC). In this case whatever happens inside of the decoder chip could add any amount of jitter, some of which may depend on the brand of CD used, burner speed, phase of the moon, etc.
Anyway, the job of CD player is to play the digital data on CD, and ignore color/brand of CDR. Same thig as DAC whose job is to play incoming digital samples and ignore the inevitable embedded SPDIF jitter. So a CDP which sounds different with bit-identical CDs, or a DAC which sounds really different depending on the digital source or SPDIF cable is not "transparent", it is crap. Like a regulator with 0dB PSRR, you could call that "transparent"...
Anyway, who is still using CDs ?
The manufacturers also don't see audio playback as an issue. They refine their production processes for speed and player compatibility. The right dye applied to a good substrate made from a good stamper that can be used in any player/recorder.
If you want to test/refine your writing process there are a few free programs that you can use or you can invest in a CDCATS or DaTARIUS tester. You will still not know if the discs sound better, only how well the data has been recorded on the disc.
If you want to test/refine your writing process there are a few free programs that you can use or you can invest in a CDCATS or DaTARIUS tester. You will still not know if the discs sound better, only how well the data has been recorded on the disc.
My question is valid, why not point some new research or explanations as to why these disks sound different, instead of trying to brush my question under the rug and make silly accusations.
I am asking for a reason, I am wondering why some copies of disk do seem to sound different than the original, yet when ripped to hard drive sounded perfect. Hence why I am questioning the mechanism that causes this (if my perception is correct) and why I suspect dodgy replay and the error correction working harder. There has to be a real reason and mechanism otherwise it is just perception playing games.
As to the modern age sweeping 'US' by, I work on high end very high speed PCBs and on quite complex systems, so please post some links to new research because if data is copied correctly it is ALWAYS exactly the same.
I am asking for a reason, I am wondering why some copies of disk do seem to sound different than the original, yet when ripped to hard drive sounded perfect. Hence why I am questioning the mechanism that causes this (if my perception is correct) and why I suspect dodgy replay and the error correction working harder. There has to be a real reason and mechanism otherwise it is just perception playing games.
As to the modern age sweeping 'US' by, I work on high end very high speed PCBs and on quite complex systems, so please post some links to new research because if data is copied correctly it is ALWAYS exactly the same.
Sorry Peufeu and Mark I was replying to Terry O's comment, I should have made that clear, didn't see your responses. Thanks for the answers instead of the usual shrug me off cos I'm trying to understand whether a sound difference is real or perceived, I don't like to judge by perception alone it can be fooled.
I have everything ripped to a couple of hard disks now, and have tried all the different things the 'bits aint bits' brigade have suggested that changes the sound and have not noticed any difference, between music stored on a solid state drive my laptop a dedicated PC, nas drive...all were streaming wireless to exclude noise transfer down wires...and I can happily say I heard no difference and even my missis in the kitchen (a baking mad non audiophile) could not detect any difference, even when prompted.
I have everything ripped to a couple of hard disks now, and have tried all the different things the 'bits aint bits' brigade have suggested that changes the sound and have not noticed any difference, between music stored on a solid state drive my laptop a dedicated PC, nas drive...all were streaming wireless to exclude noise transfer down wires...and I can happily say I heard no difference and even my missis in the kitchen (a baking mad non audiophile) could not detect any difference, even when prompted.
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Yeah, there is a lot of mythology on this subject. For example different brands of CD-Rs, or burn speed, are supposed to sound different. The relevant test to realize that digital data errors are not the factor here is to connect the CDP's SPDIF output to a PC and record the SPDIF bitstream, making sure the soundcard settings allow bit-exact recording. Without surprises, all the CDs produced bit-exact SPDIF output. What came out of the CDP SPDIF output was identical to what the PC had burned on the disc.
Except for some players, most notably CD723 of course, the crappiest CDP on earth, which had a buggy digital volume control which cannot be set to 100%, so it multiplies all samples with 0.9999 and truncates the result, getting rid of all low level information and any dithering originally embedded in the 16-bit samples. Some other players have buggy digital volume controls too, some dither some just truncate, in all cases a digital volume control which outputs to only 16 bits is always crap. If the player outputs a volume-controlled bitsteam on the SPDIF output, it is easy to check. In any case, choosing a player without digital volume control seems wiser.
Also some players have buggy oversampling filters which will overflow and wrap around on peaks. This is easy to check on a scope, so I don't care what someone thinks if he did not check. This is off-topic though as it does not depend on the brand of CDR used.
Anyway, when I see some audioblaberring about needing a CD transport mechanism built like a bulldozer to avoid digital read errors, the first thing that comes to my mind is the idiots talking did not check if there were any read errors in the first place by simpy recording the SPDIF output with a PC.
Big News : the $5 CD transport from a junk bin chinese crap multiformat CD/DVD player, or a $20 PC CD/DVD drive, has exactly the same digital read performance as a $5000 Esoteric transport, ie, they can both read CDs. Wow, who'd have guessed that.
Now is the time that subjectivists start yelling, but I'm not saying they're wrong...
If there is actually a difference in the listening results, please search for the cause everywhere you like EXCEPT in digital read errors, because it takes just a few minutes to prove that there are no digital read errors.
Regarding digital errors in SPDIF transmission, you can stick a LED on the ERROR output of your CS8416. I did that for you, if the cable is reasonably good (like a $1 supermarket video cable), there are none. SPDIF works perfect to transmit the bits (but fails horribly at transmitting the clock, as everyone knows).
So a few years ago I stuck my scope probes in various CD players and found out what I explained in the previous messages. FFS, the power supply in the CD723 was so unbelievably bad that the pickup actuator current, when it compensates for vibration, would modulate everything including the DVCC, so even the SPDIF output would wobble on the scope if someone walked in the room...
In this case I can understand the importance of a well-centered CD, or a heavier case, or a solid heavy mechanic : less vibration, easier job for actuators, less supply modulation. A well designed power supply is another solution, though...
Anyway, yes, bits are bits, period, end of debate.
However a DAC has lots of inputs, and the digital bits are just one of the inputs, but the other inputs are just as important for performance : the clock obviously, the analog reference voltages, the power supplies, etc. Also the rest of the analog stages in a CDP all have hidden inputs : GND, V+, V-, and EMI coupling.
So the bits are only half the story, it is the easy part to get right, and easy to verify that it is perfect. The rest is analog, much harder to get right and verify.
For example I have an ES9018. It can sound wonderful (and measure well), or sound like crap (and measure like crap) if the analog supplies are clean or dirty. No surprise.
For example, one could stick a probe in a CDP and measure the noise caused by the ASICs using a RF spectrum analyzer, and notice that various brands of CD-Rs produce different noise profiles. Why not ? They will all have different SNR, embedded jitter, etc.
Of course noone is going to do that test since that would actually produce results.
Don't count on me : I don't own a CDP anymore.
Another test would be to check for jitter on the analog output with various brands of CDR. Much easier test...
The fun part is that, since I think the main cause of the topic's phenomenon is noise coupling, it will be different between different models of CDPs, so there is no reason that the CDR that gives the best result for player X will be the same for player Y ...
I can agree with that, cheers.
As I said I do not like to trust a perceived difference in sound without some backup and understanding of what is causing the difference, if there is any and I haven't imagined it and I do find expectation bias does have a big influence on your perceptions. its a pity that you are derided by some for wanting to understand and find the problem instead of blindly following some way out beliefs and worshiping a new audio guru....
As I said I do not like to trust a perceived difference in sound without some backup and understanding of what is causing the difference, if there is any and I haven't imagined it and I do find expectation bias does have a big influence on your perceptions. its a pity that you are derided by some for wanting to understand and find the problem instead of blindly following some way out beliefs and worshiping a new audio guru....
On the topic of CD-R slugs having different sonic characteristics, wouldn't that goofy notion pass on to hard drives as well? What about other data storage devices? Are people picking thumb drives based on sonics if they want to bring high res files to a friend's house to listen?
I think the problem here is when the audio industry started to move into the computer / data realm, way, way too much audiophile spooky dogma came along for the ride. It ended up propagated by people who didn't understand the technology when it was in it's infancy, and expectation bias keeps them there.
The truth is, if CD-Rs sound different, every other digital storage device should follow suit. Nobody talks about those, however. I think part of it is CDs were in use before the internet became popular, so it gave the dogma a better chance to take hold as audio circles tended to be smaller, whereas now, suggesting one hard drive or thumb drive sounds better would be laughed out of the conversation so fast just the fear of appearing stupid keeps those ideas on the skull side of the mouth.
Edit: And even more interesting, what about cable modems? Is there a specific brand people should ask for so as to not ruin their high-res downloads? I mean, wtf.
I think the problem here is when the audio industry started to move into the computer / data realm, way, way too much audiophile spooky dogma came along for the ride. It ended up propagated by people who didn't understand the technology when it was in it's infancy, and expectation bias keeps them there.
The truth is, if CD-Rs sound different, every other digital storage device should follow suit. Nobody talks about those, however. I think part of it is CDs were in use before the internet became popular, so it gave the dogma a better chance to take hold as audio circles tended to be smaller, whereas now, suggesting one hard drive or thumb drive sounds better would be laughed out of the conversation so fast just the fear of appearing stupid keeps those ideas on the skull side of the mouth.
Edit: And even more interesting, what about cable modems? Is there a specific brand people should ask for so as to not ruin their high-res downloads? I mean, wtf.
Er if you look around you'll find threads that actually cover not only different sounding drives, SSD vs Hard drives, using different PSUs to rip CD's (that was a good one, I believe even though the data was bit identical there were differences in the sound, we off a more objective nature reckoned that they had discovered 'Dark Bits'), different SATA cables (another fun thread, started by someone ; there is nothing that has not been discussed to death, even looking at square waves on a scope and determining the resultant sound output from that.
Anyway for your reduced sanity I would suggest theses as a starter:
http://www.diyaudio.com/forums/pc-based/202369-hand-made-sata-cable-cat.html
http://www.diyaudio.com/forums/pc-based/243782-diy-usb-cable.html
http://www.diyaudio.com/forums/digital-line-level/141902-whats-best-method-rip-cd-hdd.html
http://www.diyaudio.com/forums/digital-line-level/142077-i-need-hand-rally-scientists.html
http://www.diyaudio.com/forums/pc-based/228337-usb-cable-quality.html
Have fun....
Anyway for your reduced sanity I would suggest theses as a starter:
http://www.diyaudio.com/forums/pc-based/202369-hand-made-sata-cable-cat.html
http://www.diyaudio.com/forums/pc-based/243782-diy-usb-cable.html
http://www.diyaudio.com/forums/digital-line-level/141902-whats-best-method-rip-cd-hdd.html
http://www.diyaudio.com/forums/digital-line-level/142077-i-need-hand-rally-scientists.html
http://www.diyaudio.com/forums/pc-based/228337-usb-cable-quality.html
Have fun....
So, by extension, certain hard drives must also be able to store higher quality data for every application, so there should be hard drives that do things like, for instance, make the color of the title bar in a browser window more vivid. Same thing for ram, I guess.
I gotta stop coming into threads like this, I'm starting to go grey prematurely.
I gotta stop coming into threads like this, I'm starting to go grey prematurely.
I am looking for the hard drive that will store my photos as modern masterpieces and save me using Lightroom 5.
I did get rather frustrated on one or two threads...well all off them.
Julf, don't tempt us so, we need a link.....I need to compare such a cable with the £5.48 35m cable I have just bought of amazon, that's 15p/m so at 6000x the cost I expect it to be 6000x better
I did get rather frustrated on one or two threads...well all off them.
Julf, don't tempt us so, we need a link.....I need to compare such a cable with the £5.48 35m cable I have just bought of amazon, that's 15p/m so at 6000x the cost I expect it to be 6000x better
Are you seriously saying that you don't care about the direction of the flow of the music?
Don't be silly! Of course you will still hear the music, but it won't be as musical. It won't be foot-tapping and the timing will be all wrong, and all the digital graininess will be audible. Even your neighbour's wife will walk in to remark how the music suddenly sounds veiled and unnatural. Not knowing your neighbours, I don't know if that is desirable or not...
Haha, that's just fabulous.
Anyway my laptop's headphone output is so transparent that I can tell if I'm listening to harddisk or network, or even if the file is fragmented or not... 'cause the supply filtering inside is so "transparent" that everytime the harddrive head moves, it makes a "crrrtttt" sound on the audio output... when Windows Update does its thing, it sounds like a hailstorm.
The +5V on the USB connectors seems to nicely track whatever's inside the laptop too... I should try a voltmeter as a cpu load indicator...
Indeed, there are some computers with really bad ground loop issues, but they generally only affect the analog outputs.
Julf, that is absolutely ridiculous. If the cables are in backwards the music will play backwards. Even a newbie audiophile knows that.
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