In theory, when light goes through acrylic or similar material, some radiation will ocurr (this characteristic is used in some aircraft backlit panels), thus causing some error in the data being read from the disk. A slanted edge threoretically will reduce this radiated light from reflecting back into the material. In the early days of CD, there was a product that used a marker to color the CD edge. The CD lathe does a 36 degree cut in addition to the marker.
I just wanted to know whether anyone else had used this product before.
I just wanted to know whether anyone else had used this product before.
I warm up my CD's in microwave, this way I dont need to wait cd to warm up inside cd-player and i get constant transient response every time, any day. For best results use ½ power for 10-15 secs, some experimentation and listening is needed to get timing right for invidual microwave ovens. now for real, dont try this at home. 
mjjz,
I know you were joking, but some people may get strange ideas, so before anybody tries something stupid, better have a look here first.
www.prairienet.org/~tatwell/cd_burning.html
I know you were joking, but some people may get strange ideas, so before anybody tries something stupid, better have a look here first.
www.prairienet.org/~tatwell/cd_burning.html
Been having an email debate with a friend who recently bought one. Today he cut half a dozen carefully chosen CDs for me. The difference was immediately noticeable. Meat Loaf was so poorly recorded I stopped listening to it, the cutter brought it back to nearly decent. Just listening to an 80s recording which seems to have a lot more life to it now (punchier bass, more resolution across the whole range). Can't here any appreciable difference on Joe Satriani which is a very good recording. Not sure I want to fork out the dollars they are asking for these things but I am no longer sceptical about the result, the difference is real.
This is a german manufacturer
Audiodesksysteme Gläß - High End Produkte und feinmechanische Geräte
Audiodesksysteme Gläß - High End Produkte und feinmechanische Geräte
Cutting a bevel on the edge can improve a poor recording? That is an amazing claim. I find it hard to believe that it can change poor playback; to improve the recording would require a time machine!Silent Screamer said:
It is just about conceivable that a poor CD on a poor player with such marginal data reading that it is frequently interpolating instead of correcting could sound better if internal reflections were changed. In all other situations it can't affect the data, so the most that could happen is a small change in jitter due to poor design. Certainly no 'light and day' changes.
I often wonder why there isn't a push (instead of all the subjective chatter) to just do an "A:B" recording of the supposedly improved segments of a recording, and compare them at the data level? Doesn't even need to be synchronous. Take a CD, play it in system "A", record on a computer through the audio jack. Cut little swastikas or happy faces in the rim, play it again, and record it again with the same equipment.
Now there are two files, preferably WAV type (i.e. uncompressed recordings).
Use a "correlator function" to align the playback segments easily to within one sample length. (You also get "for free" the optimum scaling factor to get the B signal as close to A in amplitude as possible.) (You also get for "double-free" the accumulated difference between the signals! Cross-correlation is such a powerful DSP technique)
Then, take a Fourier transform of [B minus A], to see what spectrum of differences lie in the data. There are a lot of people here who would bet on "none". I'm in that group.
HOWEVER - DF96 does make a valid point, that for somewhat abraded CDs on CD players that haven't got a very clear 1-0 discriminator, reflected edge light could increase the noise feedback, thus increasing noise of the signal, decreasing data integrity, and in turn requiring the built-in multi-level error-correction to kick in. Much of that ECC is 'perfect', in reconstruction of missing chunks ... but at the highest level, the CODEC is also tasked with simply in-filling small segments that can't be reconstructed, from those segments that have just passed. Interpolation.
So yes ... could be. And what makes for a "poor CD player"? Turns out that the big gotcha is micro-dust. Gradually builds up on all those horizontal flat laser lenses. Like the (expected, planned, normal) dust build-up on astronomical telescopes, it doesn't much impact the image, even when it is somewhat remarkably copious ... but the effect is to increase the general 'haze' or black-level noise. Poorer contrast. Wash-out of the dimmest stars. Same with the laser in the CD player. Dust doesn't affect focus, but does inject a noise-floor into the digital 1/0 reader. If the CD is already "noisy", then this lifted noise floor just makes the data 'noisier'.
Is it advisable to clean the poor little laser read-back unit from time to time? Probably "technically", but for most folks, its like cleaning one's reading glasses with a gummy toothbrush. NOT recommended.
GoatGuy
Now there are two files, preferably WAV type (i.e. uncompressed recordings).
Use a "correlator function" to align the playback segments easily to within one sample length. (You also get "for free" the optimum scaling factor to get the B signal as close to A in amplitude as possible.) (You also get for "double-free" the accumulated difference between the signals! Cross-correlation is such a powerful DSP technique)
Then, take a Fourier transform of [B minus A], to see what spectrum of differences lie in the data. There are a lot of people here who would bet on "none". I'm in that group.
HOWEVER - DF96 does make a valid point, that for somewhat abraded CDs on CD players that haven't got a very clear 1-0 discriminator, reflected edge light could increase the noise feedback, thus increasing noise of the signal, decreasing data integrity, and in turn requiring the built-in multi-level error-correction to kick in. Much of that ECC is 'perfect', in reconstruction of missing chunks ... but at the highest level, the CODEC is also tasked with simply in-filling small segments that can't be reconstructed, from those segments that have just passed. Interpolation.
So yes ... could be. And what makes for a "poor CD player"? Turns out that the big gotcha is micro-dust. Gradually builds up on all those horizontal flat laser lenses. Like the (expected, planned, normal) dust build-up on astronomical telescopes, it doesn't much impact the image, even when it is somewhat remarkably copious ... but the effect is to increase the general 'haze' or black-level noise. Poorer contrast. Wash-out of the dimmest stars. Same with the laser in the CD player. Dust doesn't affect focus, but does inject a noise-floor into the digital 1/0 reader. If the CD is already "noisy", then this lifted noise floor just makes the data 'noisier'.
Is it advisable to clean the poor little laser read-back unit from time to time? Probably "technically", but for most folks, its like cleaning one's reading glasses with a gummy toothbrush. NOT recommended.
GoatGuy
Note to Silent Screamer - One can have a $5,000 CD player, and it may very easily have a poor 1/0 discriminator. See what I write above. The more expensive the player (I've found), very often much of the little stuff that goes into cheap consumer players to make them especially reliable in the hands of monkeys, is left out. Audiophiles are expected to treat their equipment and media "better" than monkeys.
But... the sad truth is that expensive equipment is often expected to last MUCH longer than inexpensive 'throw-away' equipment. Thus... dusts can (and do!) build up as the equipment ages. And being "audiophile" grade, the equipment is used more. More CDs played (more little wafting-ins of air + dust per day).
GoatGuy
But... the sad truth is that expensive equipment is often expected to last MUCH longer than inexpensive 'throw-away' equipment. Thus... dusts can (and do!) build up as the equipment ages. And being "audiophile" grade, the equipment is used more. More CDs played (more little wafting-ins of air + dust per day).
GoatGuy
There's a few angles to this.
People who know how CD players work realise that the laser emitter and the detector float a few mm above (or below as the case is) the surface. Further, they know that the laser doesn't particularly 'flow' the CD - it is tightly focussed on the bottom of the pits. So, a pit botttom reflects a signal, and the CD surface does not, which gives the detector the idea whether it is reading a pit or not. Some pits are short, some are long and that determines whether the read bit is 1 or 0. Then there's the decoding, formatting, error correction etc that results in a data stream to the DAC.
So, we ask, how does any real or imagined reflection of 'something' from the spinning edge changes this data stream - and, incredibly, not messing it up but subtly changing it so that humans with ears find it sounding better. Alter the data stream in such a way that transients sound better! And it does that presumably on the whole CD, whether scanning close to the edge or to the spindle. A stretch of the imagination if there ever was one!
The other side is the report by an individual who spend money in the expectation that this changes the sound for the better - not just changes it, but actually makes it better! We all know about perception, don't we, all the factors that go into the perception of sound, not just the air vibrations but the expectations, the peer reviews, the money spend, the superficial credibilty etc. And in the light of all this we are to believe that the report from an individual is the objective truth. Another demand on our imagination.
So, to be convinving to many people, it has to be convincingly shown that 1) there is a clear technical cause that could result in 'better sound', and 2) a convincing story that the individual's judgement is objective, for instance arrived at by a controlled statistically valid test.
jan
People who know how CD players work realise that the laser emitter and the detector float a few mm above (or below as the case is) the surface. Further, they know that the laser doesn't particularly 'flow' the CD - it is tightly focussed on the bottom of the pits. So, a pit botttom reflects a signal, and the CD surface does not, which gives the detector the idea whether it is reading a pit or not. Some pits are short, some are long and that determines whether the read bit is 1 or 0. Then there's the decoding, formatting, error correction etc that results in a data stream to the DAC.
So, we ask, how does any real or imagined reflection of 'something' from the spinning edge changes this data stream - and, incredibly, not messing it up but subtly changing it so that humans with ears find it sounding better. Alter the data stream in such a way that transients sound better! And it does that presumably on the whole CD, whether scanning close to the edge or to the spindle. A stretch of the imagination if there ever was one!
The other side is the report by an individual who spend money in the expectation that this changes the sound for the better - not just changes it, but actually makes it better! We all know about perception, don't we, all the factors that go into the perception of sound, not just the air vibrations but the expectations, the peer reviews, the money spend, the superficial credibilty etc. And in the light of all this we are to believe that the report from an individual is the objective truth. Another demand on our imagination.
So, to be convinving to many people, it has to be convincingly shown that 1) there is a clear technical cause that could result in 'better sound', and 2) a convincing story that the individual's judgement is objective, for instance arrived at by a controlled statistically valid test.
jan
I am not familiar with the players mentioned, but it is not unusual for an expensive player to have exactly the same mechanism and logic circuitry as a cheap player. The extra money is spent on things like the analogue circuitry, the power supply, the case, the badge and the marketing spiel. None of these (except, perhaps, the PSU) will have any effect on data integrity so an expensive player and a cheap player are effectively in the same boat.
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