peanutbutterjam Posted January 17, 2009 Report Posted January 17, 2009 Hi, I hope this isn't a stupid question, but anyway: How is a $2000 CD transport better than a $200 one? As far as transports go the output is entirely digital, there are no analog stages that can be affected by inteference/component quality/etc. So what's the difference? Digging through doesn't seem to yield any definitive answer. I wish I could A/B them, but unfortunately its hard to come by in my area. Thanks!
Torpedo Posted January 17, 2009 Report Posted January 17, 2009 Hahaha, completely wrong mate, the electric signal coming out from a transport is entirely analogue, which is not to say that the information is analogue. Different things if you think about it carefully.
grawk Posted January 17, 2009 Report Posted January 17, 2009 No, I think he means a transport used to feed a dac.
peanutbutterjam Posted January 17, 2009 Author Report Posted January 17, 2009 No, I think he means a transport used to feed a dac. Yep that's exactly what I meant. Has anyone tried A/B different transports before?
aardvark baguette Posted January 17, 2009 Report Posted January 17, 2009 any definitive answer Just like most everything else in audio.
Torpedo Posted January 17, 2009 Report Posted January 17, 2009 No, I think he means a transport used to feed a dac. I know, and to that I replied. The electrical signal isn't digital, it's not pulses or anything really "digital" it's an electrical signal showing volt vs time variation. Replying to the if I have A/Bd them, yes, I have A/Bed transports many times and they don't sound the same. There are differences even depending on the DAC used.
deepak Posted January 17, 2009 Report Posted January 17, 2009 Yep that's exactly what I meant. Has anyone tried A/B different transports before? Not A/B, but I have heard differences in transports feeding DACs.
spritzer Posted January 17, 2009 Report Posted January 17, 2009 I've compared a lot of transports and even built my own (Shigaclone) and they sound very different from one another. This isn't just limited to disk spinning units as USB transports aren't all the same and benefit from a better PSU.
peanutbutterjam Posted January 17, 2009 Author Report Posted January 17, 2009 I know, and to that I replied. The electrical signal isn't digital, it's not pulses or anything really "digital" it's an electrical signal showing volt vs time variation. While it can indeed be an electrical signal, it is a 1/0 square wave (ideally) signal. I.e. the system only recognises the 2 different voltages, one for 1 and the other for zero. If we arbitarily assign them +1 and -1V, it doesn't really matter if interference or poor components causes it to become +1.01V cause the system will just take it as 1 in binary. Replying to the if I have A/Bd them, yes, I have A/Bed transports many times and they don't sound the same. There are differences even depending on the DAC used. Btw please don't take it as a challenge or a check of your authourity on this subject or anything. I asked simply to hear other's experinces with different transports. As for what you have tried, how does the quality of the transport scale with cost? Just like most everything else in audio. Hmm... That was exactly why I put $200 vs $2000, and not $200 vs $220. I though that if people were paying 10x more there must be a reason right. Or maybe that's just my wishful thinking
Dreadhead Posted January 17, 2009 Report Posted January 17, 2009 One thing to remember is that if you paint the walls of a room a different color people will be in a different mood in it and this will effect what they hear. I'm tempted to think that much like hard disks digital audio is fairly error tolerant (could you imagine if the data came off the hard disk differently depending on what disk it was on).
justin Posted January 17, 2009 Report Posted January 17, 2009 One thing to remember is that if you paint the walls of a room a different color people will be in a different mood in it and this will effect what they hear. I'm tempted to think that much like hard disks digital audio is fairly error tolerant (could you imagine if the data came off the hard disk differently depending on what disk it was on). Audiophile hard drives? you sir are a genius
deepak Posted January 17, 2009 Report Posted January 17, 2009 One thing to remember is that if you paint the walls of a room a different color people will be in a different mood in it and this will effect what they hear. I'm tempted to think that much like hard disks digital audio is fairly error tolerant (could you imagine if the data came off the hard disk differently depending on what disk it was on). Say the hard disks are error free, but what about the hardware sending the digital stream to the DAC? Like the sound card or the USB bus...
Dreadhead Posted January 17, 2009 Report Posted January 17, 2009 Say the hard disks are error free, but what about the hardware sending the digital stream to the DAC? Like the sound card or the USB bus... Well at I own 3 usb hard drives I did not say error free I said error tolerant. USB does have some issues since it's asynchronous and this can certainly cause problems in that the music drops out. That said if they digital signal gets through the only thing I can see being an issue is the jitter in the digital signal. Jitter could be the cause but I'm not so convinced because some "amazing" transports have jitter problems and other so so transports have great jitter. Also tests on the audibility of jitter are very suspect. Another possible source is some kind of DSP going on in the transport which of course can make a difference. I'm not saying that they don't sound different but that I don't see why they should sound different. They are taking digital data and delivering it, there are lots of devices that do this very well ranging from digital cable to cell phones and I don't see why it will take 2 grand to do this with CDs.
Pars Posted January 17, 2009 Report Posted January 17, 2009 While it can indeed be an electrical signal, it is a 1/0 square wave (ideally) signal. I.e. the system only recognises the 2 different voltages, one for 1 and the other for zero. If we arbitarily assign them +1 and -1V, it doesn't really matter if interference or poor components causes it to become +1.01V cause the system will just take it as 1 in binary. The data portion (i.e., the music) of the S/PDIF signal is digital. Most people forget about the clock (running at 2.8xxx MHz) which is riding on the S/PDIF signal; this is actually RF and is analog in the sense that it is the timing and not the levels that are of interest here. Very poor design (clock and data on same signal), but its what you're stuck with. Btw please don't take it as a challenge or a check of your authourity on this subject or anything. I asked simply to hear other's experinces with different transports. As for what you have tried, how does the quality of the transport scale with cost? Hmm... That was exactly why I put $200 vs $2000, and not $200 vs $220. I though that if people were paying 10x more there must be a reason right. Or maybe that's just my wishful thinking I normally don't use a sep DAC, so I can't comment on different transports, etc.
Torpedo Posted January 17, 2009 Report Posted January 17, 2009 While it can indeed be an electrical signal, it is a 1/0 square wave (ideally) signal. I.e. the system only recognises the 2 different voltages, one for 1 and the other for zero. If we arbitarily assign them +1 and -1V, it doesn't really matter if interference or poor components causes it to become +1.01V cause the system will just take it as 1 in binary. Btw please don't take it as a challenge or a check of your authourity on this subject or anything. I asked simply to hear other's experinces with different transports. As for what you have tried, how does the quality of the transport scale with cost? Hmm... That was exactly why I put $200 vs $2000, and not $200 vs $220. I though that if people were paying 10x more there must be a reason right. Or maybe that's just my wishful thinking Not very sure the data part of the SPDIF signal is square waves, that's initially what the pits and dots engraved on the shiny discs produce, but once those changes in the level are integrated to form the eye pattern wave and are later mixed with the clock data, it's not that simple. It's an AC signal looking pretty analogue. I have no authority mate, just some experience fiddling with gear, that's all. IMO there's nothing like true sound quality and musical results scaling with expense. I've used many different transports, from pro ones into CD recorders to vintage Theta laserdisc readers, going through boutique ones, inexpensive DVD-V players and midrange universal players. All I've learned is that generalizations cannot be made, and largely depend on the DAC you're using and the link between the transport and DAC. I've found really good transports that have excellent error correction and won't skip reading the worst condition CDs, that don't manage to really make music, just good sounds. Some others are very finicky about the discs quality, and won't read poorly pressed commercial CDs, but manage to sound really natural and fluent depending on the digital link you use. If any, the only conclusion I can take from that experience is that optical link mostly sucks music-wise. There are differences, that's sure, but to find them, and deciding if they're worth the cost, you first need the gear to put them in evidence, then using the recordings and music that may benefit from those differences.
swt61 Posted January 17, 2009 Report Posted January 17, 2009 (edited) Yep that's exactly what I meant. Has anyone tried A/B different transports before? Absolutely, and while many people seem to think that there should be no difference, in fact there are. I've compared several transports as well as CDPs used as a transport, and they all had different signatures. However the good news is that there are several less expensive transports that perform quite well. A good used PS Audio Lambda transport is one of my favorites. The California Audio Labs unit stands up quite well too. Edited January 17, 2009 by swt61
Asr Posted January 17, 2009 Report Posted January 17, 2009 Back when I owned the Accuphase DP-500 and Arcam FMJ CD33 simultaneously, I compared the Accuphase's "one-box" output to its output as a DAC only (Arcam as transport) and found a definite sonic difference. I wasn't sure which was sonically better but there was definitely a difference (though very subtle). Also given that there are several vendors who make dedicated transports (dCS, EMM Labs, Esoteric, et al), there has to be some merit to their advanced (and very expensive) mechanisms.
Pars Posted January 17, 2009 Report Posted January 17, 2009 Back when I owned the Accuphase DP-500 and Arcam FMJ CD33 simultaneously, I compared the Accuphase's "one-box" output to its output as a DAC only (Arcam as transport) and found a definite sonic difference. I wasn't sure which was sonically better but there was definitely a difference (though very subtle). Also given that there are several vendors who make dedicated transports (dCS, EMM Labs, Esoteric, et al), there has to be some merit to their advanced (and very expensive) mechanisms. Does there? Blanket statements such as this are very dangerous. Just because something is available and expensive (or not) doesn't mean it is good.
Fitz Posted January 17, 2009 Report Posted January 17, 2009 Not very sure the data part of the SPDIF signal is square waves, that's initially what the pits and dots engraved on the shiny discs produce, but once those changes in the level are integrated to form the eye pattern wave and are later mixed with the clock data, it's not that simple. It's an AC signal looking pretty analogue. I don't know what part of a BMC signal you consider pretty analog... sure looks like square waves of only two different widths to me.
morphsci Posted January 17, 2009 Report Posted January 17, 2009 .... Also tests on the audibility or inaudibility of jitter are very suspect.... FTFY
Torpedo Posted January 17, 2009 Report Posted January 17, 2009 I don't know what part of a BMC signal you consider pretty analog... sure looks like square waves of only two different widths to me. Yep, and square waves aren't analogue? What I'm trying to mean is the electrical signal is analogue in nature and what's digital to be decoded is the information it carries.
Fitz Posted January 18, 2009 Report Posted January 18, 2009 Yep, and square waves aren't analogue? What I'm trying to mean is the electrical signal is analogue in nature and what's digital to be decoded is the information it carries. No, it's not analog, unless you simply throw out the actual meaning of "digital." The electrical signal only has two discrete states, it isn't continuously variable between those two states.
Torpedo Posted January 18, 2009 Report Posted January 18, 2009 That's the theory, and then there's what SPDIF outputs throw. As I see it, the signal is analogue for being a constant wave, there are no 0 and x Volts states, but a continuous waveform changing from a voltage point to another. Abruptly and with a square shape, but in essence not very different from a sinewave. Anyway, it's just a matter of interpretation, the real point is that the SPDIF wave is under the same transmission conditions that would affect any other analogue signal carried by a IC.
Fitz Posted January 18, 2009 Report Posted January 18, 2009 So if "abruptly and with a square shape" is not a square wave, then what is it?
grawk Posted January 18, 2009 Report Posted January 18, 2009 Our fine friend mister cool torpedo is being pedantic because he's in a mood to argue, apparently.
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