Review
Tue, May 7 2013, 6:44PM
#2
RE: Review
Have to say that as someone who still plays cds, I'm fascinated by this discussion although awaiting a conclusion before I think of going out and blowing cash on equipment upgrades.
Lately I've been burning cds as flac files onto my sandisk player for portable listening and can't deny that my impression is they sound better. Which shouldn't be possible because all you're doing is encoding what's on the original cd, which surely can't be improved if it's just a copy rather than an enhancement.
Some time ago we went into subjective aspects of listening and the frailties of A-B testing. Not that I'm questioning Vic's objectivity but I am curious as to how he's done his comparisons.
Tue, May 7 2013, 6:57PM
#3
RE: Review
On a lighter note, I have been reading some volumes from the Gramophone archive, around the time of appearance of CD (1983). It's amusing to read that with the coming of Cd all recordings will be available in their perfect form, even on the cheapest CD player and that would signify the end for all this so-called hi-end nonsense.
!!!!!!!!!!
Not quite, eh!
Chris
Tue, May 7 2013, 8:22PM
#4
RE: Review
The critical question then is how the FLAC file is produced from the CD.
I'm fed and watered (well, wined) and have got my second wind, so to speak. So let me have another go.
My wife tells me that FLAC is a file format (not a program as I said earlier) which tells the computer how to read the disc. Yes, a computer and a CD player read the disc in the same way physically. The difference seems to reside in the fact that the CD player reads it once, on the fly, whereas the computer is "instructed" by the extraction software which has been set up to extract into FLAC format to read it over and over until it has one hundred percent of its content, and will only let the hard drive store it when that has happened (because it's "lossless".) I have had one or two CDs that would not rip and was told that that was the reason.The discs were faulty. The the extraction software was doing its job.
That would account for the difference in quality, would it not?
Not every single time, I guess, because there must be a chance, however vanishingly small, that a CD laser, backed up by error correction, could push out one hundred percent of what is on the disc. But if a computer, following extraction software instructions, takes on average, three minutes to do its business, what else is it doing but reading it over and over again till it gets everything? And why would it do it if one-time reading, like a CD player on the fly, produces the same quality of reproduction that is suggested by some here? That's where the difference lies.
That's it. I have exhausted both my (limited) knowledge and my capacity to express it. Andrew, help us out please!
Vic.
Tue, May 7 2013, 8:23PM
#5
RE: Review
It's still out there, Chris. I still hear people say, "But it's digital, it's just ones and zeros, how can it sound better or worse?"
I'm afraid your comment on the strange ads that have been appearing on this forum, how they might reflect on Gramophone's lack of interest, may be mirrored here. Surely this thread is over-ripe for intervention by one of G's technical gurus?
Tue, May 7 2013, 8:36PM
#6
RE: Review
But on the positive side, it has been a good, honest and open discussion, with 32 contributions, and an attempt to understand an important aspect in a new method of delivering our music.
Another sign of revival in the forum, I think.
Vic.
Tue, May 7 2013, 9:00PM
#7
RE: Review
Fine Vic,
Ive been away eating myself. We could have wished one another bon appetit beforehand!
Perhaps then its all down to whether a CD player can provide as much error correction than a computer programme on a computer.
Unfortunately I fear Tagalie is right, there has been ample opportunity for Andrew to appear, but no sign!
Never mind, it's the music that counts, and it has been a great day on the Forum. So many posts I've hardly had time to listen to any music. I'm beginning to feel that the onus is on me now to think up a thread or two now too. You've done your bit!
Anyway coming up to 11pm here, so Good Evening All! Just time for a musical nightcap.
Chris
Tue, May 7 2013, 8:59PM
#8
RE: Review
I'm not sure I can help too much, but conventional CD audio is 16-bit, 44.1kHz which means that the amplitude of the original analogue wave is sampled 44100 times each second and each value converted into a 16 digit (bit) binary number (Since 2 to the power 16 is about 65000, this means that each sample corresponds to a number between 0 and about 65000. 65000 means full volume. 0 means no volume. The process in a DAC is the opposite of this - it takes that sequence of sampled values and outputs the original analogue wave. The most basic way this sequence of data can be used on your PC hard drive is a .wav file which has an agreed format. A .flac file is just the same information but compressed. It is analogous to a .zip file when you compress a word document. The compression process can be perfectly reversed by a pc running the right software or the processor in your DS player. Once the orginal sequence of numbers has been extracted the data is sent on to the DAC.
The sequence of numbers sent by a CD transport to its DAC stage or the DS player to its DAC stage (playing either the flac or wav version of the CD) will be the same. On both hard drives and CDs the original sequence of numbers is stored with enough extra error correction information added on that this will be the case except for say CDs in very bad condition.
So the way people try and explain why there might be an audible difference in the two cases is not anything to do with the actual numbers that are being sent themselves, but instead they turn the discussion to jitter, which is small variations in the times of the intervals between the numbers in the sequence. This jitter is real and measureable, and it is true that often in more expensive components they have gone to a lot a trouble to reduce it. If you imagine a pure sine wave which is sampled into equally spaced samples which are then stretched or shrunk a little in time you will see when you recover the original wave it will have become slightly distorted. A lot of people believe this is a problem. Again I personally don't really believe this because when you consider how much distortion this might cause it shouldn't really be audible, and in any case the distortion in your speakers will be much worse.
Ted
Tue, May 7 2013, 9:07PM
#9
RE: Review
That makes sense, Vic.
I think.
Burning to flac, you're offered different compression:speed ratios. Not sure if I have this right, but I believe that the more you compress, the longer it takes flac to encode and decode. So to reproduce a lossless file it has collected all the info at the input end and then applies different algorithms according to the amount of compression. The greater the amount of compression, the more complex the algorithm. I must say, that still sounds like a programme to me. I know few mobile players support flac, which surely indicates some form of programming is involved?
I need one of these brilliant engineers that used to support me in telecom, who can explain things in terms that even a dumb layman like me can understand.
Tue, May 7 2013, 9:18PM
#10
RE: Review
Thanks, Ted, our posts crossed but that helps. On my cd burning software (Media Monkey) it asks whether I want a standard or jitter-corrected read. From what you're saying it's the latter for most accurate reproduction, right?
Tue, May 7 2013, 11:44PM
#11
RE: Review
Thanks, Ted, our posts crossed but that helps. On my cd burning software (Media Monkey) it asks whether I want a standard or jitter-corrected read. From what you're saying it's the latter for most accurate reproduction, right?
Do you mean when you rip a CD? I am not familar with this software but I guess the term jitter is being used slightly differently to refer to issues about how the laser finds the correct spot to read on the disk. If you have a fairly new drive this probably isn't necessary.
Ted
Wed, May 8 2013, 12:18AM
#12
RE: Review
Not every single time, I guess, because there must be a chance, however vanishingly small, that a CD laser, backed up by error correction, could push out one hundred percent of what is on the disc. But if a computer, following extraction software instructions, takes on average, three minutes to do its business, what else is it doing but reading it over and over again till it gets everything? And why would it do it if one-time reading, like a CD player on the fly, produces the same quality of reproduction that is suggested by some here? That's where the difference lies.
There are several degrees of seriousness of errors on a CD. All CDs have many errors at the lowest level of seriousness, even brand new pressed discs. This is nothing to worry about as these errors are corrected by using exta error codes read off the disc and the CD player doesn't have to keep retrying to read the disk. These are perfectly corrected in the CD drive hardware without you even being made aware. What you are describing is a more serious type of error that ideally most disks should have very few or none of and which your ripping software can report. For the vast majority of your CDs, assuming they are well looked after, your CD player will not present any errors in the data to your DAC. It may present timing errors or jitter, but not often errors in the values. The advantage of good ripping software like you have is that it will alert you to the odd problem should it arise.
Ted
Wed, May 8 2013, 1:23AM
#13
RE: Review
Hello friends,
There seem to be many issues debated here which my wife and I feel are confusing the central point of the quality of our listening experience.
Vic started the discussion with his view that his old CDs sounded better when ripped and played via the Linn DS. If he hears that to be the case so far so good. Since then the discussion has resorted to various ways of ripping or burning CDs to hard discs.
The start of anyistening day/evening is determined by how the digital source, however made, is transformed through the HIFU system into the analogue sound which emerges from the loudspeakers. Our experience is that this is determined by the quality of the digital-analogue-converter (DAC) that is used to link a digital source to the analogue amplifier(s) and loudspeakers. We all know that amplifiers and speakers can make a difference, so why not the DAC?
CD-players use a built-in DAC to do the conversion. Between a computer, hard-disc, or even a memory stick, an external DAC does the same job. BUT, one can also by-pass the DAC in a CD-player and use an external DAC. In the same way the digital source from a lap-top can go to an external DAC and feed the HIFI system.
We have spent a few years and a lot of money in finding out what we hear to be an excellent result for our listening, and enjoying, sessions. Our many professional musician friends ask to hear their own recordings on our system.
What system?
Firstly, a good analogue HIFI system, i.e. amplifiers and loudspeakers. Secondly, a high quality DAC, and these do make a real difference, but they cost real money. We now have a DAC which cost 2000 euro second-hand, and the same (French!) manufacturer now has a reference DAC costing 6000 euro! Thirdly, we have replaced our old CD-player, with built-in DAC, with a high quality CD transporter which does not have a built-in DAC. It feeds into the eternal DAC. There is much more information and indeed musicality on a red-book CD than normally assumed or indeed heard. Fourthly, other digital sources, such as a cheap laptop used for streaming radio stations - who needs FM? - also feeds into the external DAC. Finally, any hard-disc and/or memory stick can also be linked to the external DAC.
Maybe we are old-fashioned, but we are convinced that the quality of the DAC is the most important element in any system intended to link digital sources to an analogue HIFI system. The professional musicians waiting to listen to their own digitally recorded work on our system is evidence enough.
The literature does suggest that there are some differences in the software used to rip CD's, but this is not the heart of the problem. The DAC is the key. Our own next move might be better loudspeakers.
As a final remark, my wife will say that the major improvement in our system was replacing our original pre-amplifier with a 'neutral' pre-amplifier which does not distort the original signal - whether digital or analogue from the LP turntable - in an way. She sings in a choir an should know.
Finally, we do not want music all around the house, do not intend to spend valuable time in copying all our CDs, and the exercise involved in walking to the HIFI to change a CD or LP is regarded here as both normal and a contribution to the need to engage in physical exercise.
Enjoy listening, however you decide to reach this most enjoyable experience.
Barry
Wed, May 8 2013, 6:10AM
#14
RE: Review
That makes sense, Vic.
I think.
Burning to flac, you're offered different compression:speed ratios. Not sure if I have this right, but I believe that the more you compress, the longer it takes flac to encode and decode. So to reproduce a lossless file it has collected all the info at the input end and then applies different algorithms according to the amount of compression. The greater the amount of compression, the more complex the algorithm. I must say, that still sounds like a programme to me. I know few mobile players support flac, which surely indicates some form of programming is involved?
As Mrs Vic says flac is a file format. When you rip a CD to flac your software will typically rip the CD to something like a temporary uncompressed wav file on your PC. The software will then pass this file to an additional bit of software flac.exe or something which performs the conversion as an additional stage. You can get flac.exe yourself separately from the web but many ripping conversion packages have it bundled in with them when you install.
The fact that the output is flac is a bit of a red herring in this discussion, the ripping software deals with errors by communicatingwith the drive at an earlier stage of the overall process, it is nothing to do with the flac conversion per se.
Wed, May 8 2013, 6:29AM
#15
RE: Review
I don't know about how Chris feels, but I sense I am getting closer to an understanding of what is going on thanks to Tagalie, Barry and Ted above. The DAC seems to be a major player.
A friend said to me last evening that, in his head, the difference between a CD player and a DS player is the difference between the old Walkman and an iPod: one uses a physical object as the music holder and requires moving parts to extract it; the other doesn't.
A Walkman had no "error correction" so not a perfect analogy, but it seems to make sense to me.
I want to know how a DS (and an iPod) works! Therein must lie the key to the difference in sound quality.
I would like to hear Andrew Everard's experiences with top CD players and his obviously superb Naim digital streamer.
Vic.
But we come back to the point that why should the CD read by the computer or NAS using FLAC sound any different to the CD read by the CD player? The only difference I can see is that there must be something outside the digital domain which is giving Vic's improvement.
From my own limited experience I have to agree with Ted's comments on the audible differences between DAC components & I have commented previously on how if I were subjected to a blind listening test between a cheap supermarket DVD player I have and a CD player praised by Gramophone at 10 times the price I doubt I'd be able to say which was playing.
Changing components in the analogue circuitry could though make a difference. I have always been somewhat sceptical about this but some years ago the designer of one of my valve amplifiers suggested some component upgrades which I decided to try out. Much to my surprise, changing the type of one electrolytic capacitor in each channel did produce a subtle improvement although I was less convinced by another capacitor change elsewhere in the circuit (although the upgraded amp was regularly used as reference by the Editor of a HiFi magazine for his equipment reviews).
Designers do "voice" equipment and I was interested to read in Gramophone a comment from the Technical Director of the Audio Partnership (Cambridge Audio) that a recording he & his team often used was the Chung/Previn/LSO Tchaikovsky concerto.