So, the old CD player that I've had since being a student is starting to falter and I'm looking to buy a guality digital source for two-channel stereo.
My natural assumption has been to purchase a CD or SACD player (e.g., Shanlin, Primare) but I am starting to consider a hard-disc based system. This option involves a computer with a large hard-disk, good external DAC and lossless music files (not .mp3)
Does anyone have experience with a good quality hard-disc system? What are the relative merits of a CD/SACD player versus such a hard-disc system? My main interest is in the sound quality.
I have no exerience with any hard disc systems. However, two advantages I can think of to buying the dedicated player would be; 1) the hard disc options are in their infancy and will change many times befroe the format is settled. Probably with startling frequency. B) Cover art and possessing your music on a physical disc you can hold in your hands.
Andrew, since you asked.... The retail and legal downloadable formats offer so much more. Warranties, legal protection and higher quality.
Rips or Burns offer no such quality guarantees, and suffer the stigma of rips, per se. I really have to say that the feel of a cd(used to be lp) is something of substance, although the artwork of cd's are not up to the standards of lp's(Max Webster's Universall Juvinilles comes to mind), and although printers can do some pretty good work, the Artist's efforts are always worth the appreciation. Please allow me to repeat, The artist's work is always worth the appreciation.
I suspect you are asking whether it is an option to store the audio files you have bought, most likely on CD, on magnetic disc, and play them from there.
The answer is "Yes".
Most recent desk-top computers have optical digital in and out. If you store the files as exact copies in native format (.aiff for CD) without compression, then play them through optical link to an amp with a good DAC, then I think the sound will certainly be HiFi. If ithere is some extra magic in the Cd player transport, then take the digital out from the player to the computer
I have messed around with various audio programs. Apple's iTunes is now everywhere because of iPod, and is very good. You can certainly save files in full CD format. Quicktime movie player Pro (about £20/US$30) will do the same and is more versatile, allowing different file formats and sampling frequencies.
Jan writes "1) the hard disc options are in their infancy and will change many times befroe the format is settled"
The file format for CD (linear PCM; 44.1 kHz; 16 bit) was carved in stone in the early 1980s and that is all that matters. The recordings have always been made to magnetic disc before transfer to CD (even to LP in the early days). Higher sampling frequencies and sample sizes are possible for LPCM and these are the basis of DVD-Audio. SACD files are strongly encrypted and cannot be copied.
I, too, like discs, artwork, and paying performers, but I do not think sound quality is sacrificed by missing out real-time CD playing. In fact, you can record from an original source, on a modern computer, at much higher resolution than that specified in the CD format.
The optical out from PC is inferior to that from a dedicated CD player. It is not that simple that a CD track is picked up in digital format and transferred to DAC.
Before DAC there are a digital filter (what is referred to as x times oversampler) and possibly jitter correction (data reclocking). Both are critial in data reproduction. A computer is usually very incompetent in these two areas. Therefore, its digital output is not as accurate as we want it to be. The direct consequence is that you lose the cleanness and airiness in the sound.
However, one can make an exact copy of a CD as a disc image, then burn a CD which is the same as the original - is this correct?
If not, how come data is not lost from non-audio files copied in the same way?
And, in principle, why should there not be a digital filter/oversampler, and data reclocking, on a computer?
The other thought I had, and to AndrewS, is that WiFi streaming seems pretty good, to me, provided the data goes in and out digitally. Then there is the problem of finding a computer that does not itself make a lot of background noise, with cooling fans and other things.
I have not tried all these options. I notice my new CD player has Toslink optical digital out. If I connect that to an equivalent input on an amplifier/receiver (I don't have one at present), why should it make any difference if the data happens to have been stored, in the interim, on a magnetic disc....?
Again, the recording process writes audio data to magnetic disc, using a computer. Recording companies could just sell us edited master "tapes", that is to say, files. Couldn't these be sold to us on optical discs? What would be the difference between these and CDs?
I can easily see your confusion which stems from a common belief that digital transmission is lossless.
Yes, you are right that a audio CD image contains exactly the same bits (ones and zeros) as the original from which you ripped the image file. No doubt about this. But playing back the audio image file is not as simple as running a computer file. Here is where most people get confused and misled.
Basically, an accurage D-A process involves playing back the (1)right bits at the (2)right time.
(1) First, you need the right bits. Being digital is not equal to being perfect. The PCM encoding of redbook CD can introduct a great amount of digital noise at the ultra high frequency band. You must filter them out before feeding it to DAC. So a digital filter is required before DAC to make sure you get the right bits in place.
(2)Pay particular attention to importance of timing. If you install Windows from CD or from hard disk, there is no timing concern at all. It is a batch process - you just want the whole process sussessfully done after all - you do not care whether or not the Windows is 25% installed after 25% of the time elapsed.
But audio is different, it is a real-time process. Think about an MSN video conferencing session over the Internet - you may get perfectly good images (good bits) but in a terrible coherence (bad timing). Unfortunately there are so many factors (mechanical and electronical) that could impact the timing of bits delivery, which happens to a critial concern to audiophiles. The timing error is also called jitter, which is a deviation from the perfect synchronization. In order to address jitter, you need to buffer the bits in a temporary memory and reclock them in the right timing order. More stringently, your digital out should contain a independent channel that passes this timing data along to the DAC. This data reclocking ensures that all the subsequent digital process acts on the same clock, a uniform precise clock.
Back to your home computer, it is usually equipped with a digital filter. But its grade can pose a concern to HiFi enthusiasts. Data re-clocking? No way in a PC! Even the majority of today's dedicated CD players do not come with data re-clocking (jitter-correction). Theoretically, you should not hear a difference among the master CD, the original commercial CD and the burnt CD, if jitter correction is seriously implemented. That is how XRCD develops its concept and prevails into the HiFi market.
But XRCD cannot clock the bits once they are read into your CD player, so jitter is only minimized to the extent that the CD manufacturer can possbily do (best effort).
USB has nothing to do with timing correction. It is a transmission interface technology per se.
To resolve jitter, you must physically do the reclocking, somewhere, somehow, by something. The output digital signal must contain both the original music bits and the added timing bits, both done at an ultra precise level. It is sophisticated and expensive!
Without an authoritative clock on the playback end, the time is variable (not the time defined by God) causing the data volume to be variable by second. This is a distortion as the redbook stipulates that there should be only 1,411,200 bits in every second of data.
So aggregately you have the correct amount of music data on the disk but you cannot retrieve the correct amount of data in every second of playing it back. The jitter distortion may be unperceptible if you care enough to minimize and correct it.
Remember computer is designed for data. Audio data is digital but you cannot appreciate it until it is translated back to analog. It is the tranlation that makes things unbelievably messy, of course to the audio purists only.
That is really good, Ruve, thanks. I have been reading about "jitter" here, but you write it in words I can understand. I also see for the first time why my new CD player needs some MB of RAM.
It still seems to me there is no technical obstacle to getting the timing right (or as good as on a CD player) for read-out on a computer, or at least a magnetic disc read-write storage device. Perhaps it is just that the market is not there?
No, it is good to be meticulous. Up to a point.
BTW I've put music files as uncompressed aiff files on an iPod, and found the sound, on replay through my HiFi, much the same as that coming off the CD in a player. Any differences are beyond my available time and patience, though I could put more into it. Do you happen to know how iTunes addresses jitter and clock speed? There are lots of other audio playback programs, of course. But Apple does seem to be taking digital audio technology to market, so to speak. Most of the add-ons I read about concern copy protection rather that sound quality.
John, it is a marketing consideration that makes audio playback on PC short of more advanced circuitry support.
What do you connect your computer to? If you connect the "digital out" of your computer output to a good DAC, the DAC may reclock the bits in order. Technically, this is implemented between digital filter and DAC.
I do not think iTunes or any other software-based playback addresses jitter.
As I said before, jitter correction needs (1)an physical perfect clock and (2)enforcing this uniform absolute timing throughout the digital process.
Admittedly, if jitter is already low, correction may not add perceivable audio benefit although it does bring the music closer to the wave form in which it was encoded to be.
John, what CD player were you referring to that comes with onboard memory?
I have a new Rega Apollo CD player which is supposed to have 20 MB of memory.
I have not tried the computer-as-CD-player, recently. As I wrote previously, my current amp has only analogue inputs.
Having said that, I tried some tests with a new iPod late last year, before I had the Rega Apollo, and the sound from the iPod was indistinguishable from the sound from an NAD T533 (CD/DVD player). At least with Pink Floyd....
I also own an NAD T760 AV receiver, but do not have it running, right now, with my other equipment. It has a TOSlink input. I found that that gave good sound from CDs played direct from computer or transmitted by WiFi (Apple Airport Express) - there was no real difference. The DAC in an Airport Express Base station is, however, not much good - if I made the analogue connection, instead, the sound was distinctly poorer.
I am committed to CD playback these days, but I responded because I thought, and still think, AndrewS raises a good point.
You can see the rest of my current system from my profile.
I think we are seeing a major shift in the way most people play recorded music. Even when iPodders do not download files, they rush to import tracks from their CDs.
The question is whether "audiophiles" will move in that direction, too. I can't see any reason why not, in principle. The iPod DAC itself seems OK. I can't see why there should not be an "HiFi"-grade iPod, or just a computer - even considering your remarks about clocking and jitter. Even if there is none, now, perhaps there will be, eventually. Especially now that an iPod is a recorded music storage device (see the new "iPod HiFi"), and not just a portable player for listening on headphones.
One nice thing is that you can choose your own compromise between file size, format, and resolution. The "audiophile" would give highest priority to sound quality, I guess. From my experience, I think Andrew is right to steer clear of mp3.
I agree with you, John, on that audio storage is being revolutionized to be more portable and more flexible. But I also acknowledge that the audio grade gap is still huge between PC and CD player.
I have used my laptop + Foobar for lossless audio playing. The difference turns out to be large, especially with violin and classic materials.
So, it's critical to reclock the data before it is input to digital filter / DAC. You note that a good DAC might perform this function. Do you have any experience on such a DAC?