[PhilS]

Quote:

Originally Posted by fewtch I've had to make educated guesses which take all the various factors into account, but have concluded that there aren't any significant, impactful differences between inexpensive/good and expensive/hi-end transports.

Isn't the best way to listen and not to guess?

Seriously, if you take the CDP aspect out of it and just compare units designed or used solely as transports, have you found that there are no differences? The consensus seems to be that with decent equipment, transports do indeed sound different.

 

[agile_one]

I am of the school that a cd transport can most definitely make a difference in sound quality. The higher the quality of the rest of the chain (dac, ic's, amp, cans, etc), the more apparent the difference becomes.

I recently scored a Madrigal (Proceed) CDD transport, and the difference in my setup was quite dramatic and audible - on the same order of a major amp or dac upgrade. In doing research on the CDD, I came accross this review of the Mark Levinson 31.5 transport that discusses the issues of transports affecting sound quality. My CDD has much of the same componentry and circuits of the 31.5, as ML and Proceed are both part of Madrigal (actually were, as parent co. Harmon decided to drop the Proceed brand), so it was of much interest. The Stereophile review is a bit dated (1996), but makes valid points.

My own quick comparison of a Sony D555, optical out from a Chaintech AV710, and the CDD left no doubt in my ears that a transport makes a difference. These were just quick listens for my own edification, not scientific in any way, and used the dac in my Grace m902, and the dac in a Proceed AVP-2. Cans were HD-650's, R10's, L3000's, SA5000's, and K1000's. Amps were the Grace m902, Raptor, and the balanced outputs of the AVP-2 (HD650's only).

This gear will be at the upcoming South Florida meet hosted by tyrion on June 4th, if anyone wants to hear for themselves.

 

[Slow_aetk]

Quote:

Originally Posted by Yikes I know it's uncool to quote myself but this post tells a story that might be of interest.

Current Meridian transports are pretty much taking the CD/DVD reader mechanics and control electronics out of the equation: They are using ATA connected DVD-ROM and buffer ahead the digital stream. Their output is "direct from memory" which means no jitter coming from the CD/DVD reader.

What is then the difference between a Meridian (Computerized transport), a Computer with a decent SPDIF output and a DAP like the iRiver 120/140?

 

[Jahn]

Just checking - using your hard drive as the storage device for your music eliminates the whole transport issue, but not the jitter issue, right? I mean, it's not like one hard drive is better than any other for getting the info into the digital stream for your soundcard or external DAC to time and spit out in analog, right? Sorry if this question is a bit off topic.

 

[philodox]

Quote:

Originally Posted by Jahn using your hard drive as the storage device for your music eliminates the whole transport issue, but not the jitter issue, right?

Not sure what is considered jitter and what would be considered a negative of using a harddrive, but there are many things to consider here:

1. PC's generally have dirty power.

1. The 'transport' includes the clock and other pre-DAC components as well.

1. The audio signal is travelling all over the inside of your computer instead of in a tight hi-fi layout as it would be in a transport/DAC combo.

1. All of your rips on the harddrive may not be perfect.

EDIT: As to the original question, I noticed a huge difference using my Eastsound CD-E5 as transport with my AOS Flute, even when comparing a WAV through the digital out of my MP3 player [which should have less issues than a computer since it is battery powered]. The imaging and air around the instruments was clearer and the bass was much better defined. I started a thread about this a while back and people seemed to agree with what I had heard.

Here is that thread if you want to give it a read: Link

 

[Slow_aetk]

Quote:

Originally Posted by philodox Not sure what is considered jitter and what would be considered a negative of using a harddrive, but there are many things to consider here: PC's generally have dirty power. The 'transport' includes the clock and other pre-DAC components as well. The audio signal is travelling all over the inside of your computer instead of in a tight hi-fi layout as it would be in a transport/DAC combo. All of your rips on the harddrive may not be perfect. EDIT: As to the original question, I noticed a huge difference using my Eastsound CD-E5 as transport with my AOS Flute, even when comparing a WAV through the digital out of my MP3 player [which should have less issues than a computer since it is battery powered]. The imaging and air around the instruments was clearer and the bass was much better defined. I started a thread about this a while back and people seemed to agree with what I had heard. Here is that thread if you want to give it a read: Link

Yes, PCs have dirty power but they are able to move around 10s of gigabits/s without errors, all day long. Also the Iriver's are running from batteries which should be a very good PS.

Yes, the PC clock is probably not very good but a reclocking DAC would take care of that.

Yes, longer datapath in a noisy enviroment is favorable to jitter. Again a reclocking DAC would take care of that. But a very good transport/DAC combo is probably the best solution.

No, it is not difficult to get a bit perfect rip using EAC, even using a $15 CD-ROM drive running in a nightmarish combination of noise and vibrations. Not really a hi-end transport definition.

 

[philodox]

Quote:

Originally Posted by Slow_aetk Yes, PCs have dirty power but they are able to move around 10s of gigabits/s without errors, all day long. Also the Iriver's are running from batteries which should be a very good PS.

I agree on the Iriver, I made much the same comment about my MP3 player further in my post. You may be right about the PC's, but I think that power is still an issue. I've seen other threads on here where some forum members make comments to that effect. I don't believe everything that I read, but you do learn to trust certain peoples opinions on here over time. Quote:

Originally Posted by Slow_aetk Yes, the PC clock is probably not very good but a reclocking DAC would take care of that.

Like I said, the clock is just one of the things that comes before the DAC... and I believe there may be some issues with reclocking. One would think that it would be better to start things off well, rather than reclocking and upsampling to correct issues that are there at the start of the chain. Talk to a high end manufacturer of CD players and see if they think the transport makes a difference.

Quote:

Originally Posted by Slow_aetk Yes, longer datapath in a noisy enviroment is favorable to jitter. Again a reclocking DAC would take care of that. But a very good transport/DAC combo is probably the best solution.

So reclocking takes care of all problems that could occur before the DAC? I guess transports are useless if that is true. Quote:

Originally Posted by Slow_aetk No, it is not difficult to get a bit perfect rip using EAC, even using a $15 CD-ROM drive running in a nightmarish combination of noise and vibrations. Not really a hi-end transport definition.

I didnt say it was difficult, just that you must ensure that it is a perfect rip. I have ripped a CD in EAC in the past and though it says it is 100% whatever, there are still issues with it and it needs to be redone. I rip with the settings from bestmp3guide.com and rip either in APS LAME MP3 or WAV depending on the recording. This is only for my portable setup though as I always listen to the original source material at home now.

 

[Slow_aetk]

You may be right, the Meridian approach makes sense in getting rid of the classical CD player problem. As I could not test really that myself between hi-end transport and low-end, I left with trying to find a good explanation of what this possible difference might come from. I've not seen it yet.

For EAC, you might want to try the AccurateRip database. It integrates with EAC and calculates a checksum at the end of the rip. This checksum, is then compared with others stored in the database. If they are the same, there is a VERY high probability that your rip is perfect. I used it, mostly to check my EAC setup and I did work very well.

Frankly, I cannot find any difference in .WAV rips from the Iriver to DAC2 and CD's read by my basic, full plastic, Sony DVD player to DAC2. But neither of them is considered hi-end after all

 

[Jahn]

Hmm yep, my whole rig reeks of "mid-fi" lol - midfi source, midfi soundcard, midfi amp, midfi cans. alot in the signal is hot rodded to help the cause, but in the end of course i'd rather own a Ferrari instead of a juiced Mitsubishi - but the price is the thing lol!

 

[philodox]

Quote:

Originally Posted by Slow_aetk For EAC, you might want to try the AccurateRip database. It integrates with EAC and calculates a checksum at the end of the rip. This checksum, is then compared with others stored in the database. If they are the same, there is a VERY high probability that your rip is perfect. I used it, mostly to check my EAC setup and I did work very well.

That sounds cool, I'll check it out. I don't find that I have too many problems with my rips as it is, and when I do I just rerip and everything is usually ok at that point. Only with some severely damaged CD's do I encounter recurring problems... and in that case I usually download the tracks that have issues.

Quote:

Originally Posted by Slow_aetk Frankly, I cannot find any difference in .WAV rips from the Iriver to DAC2 and CD's read by my basic, full plastic, Sony DVD player to DAC2. But neither of them is considered hi-end after all.

I have a Sony DVD player that we got as a wedding present... possibly the same one.

I also notice very little difference [if any] between the digital output from it and my MP3 player.

 

[Yikes]

A re-clocking D/A does not eliminate jitter. It (if well implemented) can dramatically reduce jitter. There are many causes of jitter, many of them come after the bits have been read off of the disc. Even the quality of the IC can affect jitter. I’m not an engineer, but it has something to do with the fact that a digital IC acts a lot more like a wave-guide than a normal IC.

I have owned several D/A’s that had re-clocking circuits. When I had the DAC1 I played around with several different transports and they definitely made a difference, perhaps not as large a difference as with some of the non re-clocking D/A’s that I have experimented with, still there was a difference.

The Meridian DVD players are apparently doing what the Genesis Digital Lens did, buffering the data in memory then outputting a signal timed by its own reference clock. The Digital Lens made a significant improvement in most systems, of course at that point only a few manufacturers were paying attention to jitter.

Claming that a specific DAC does away with jitter because of its re-clocking circuitry is a lot like an amplifier manufacturer claiming that their new amplifier does away with all distortions because of some new technology. It might sound great, but the claim is obviously exaggerated by advertising hyperbole.

 

[bifcake]

I'm not an engineer, so my explanation may not be completely accurate, but this is what my understanding of the whole transport/dac/jitter issue entails:

Apparently, when the sPDIF stream was developed, the designers of the spdif protocol did not implement any kind of an error checking or clocking mechanism into the transport protocol. So, when the data is delivered to the DAC, it's susceptible to noise, and other anomalies that cause a certain percentage of bits to drop. This dropping of the bits is jitter. Since no error correction or clocking exists in the native spdif protocol, the transport becomes very important because the quality of the transport guarantees to a certain extent reduced jitter. The fewer points of vulnerability there are, the better chance of in tact packet delivery.

On a more practical note, I have conducted a test a while back using a Levinson 30.5 DAC with a Theta transport, a Rega Planet 2000 as a transport and a Pioneer DV-414 DVD player as a transport.

Using the Pioneer as a transport with the Levinson DAC, made it unlistenable. It sounded horrible! The DVD player used as a stand alone source sounded better than when used as a transport! It was shrill, incoherent, painful to listen to.

Theta was very polite, smooth (perhaps a bit too much) and delicate. The soundstage was ok, but not great. It didn't offend and it was very listenable.

Rega Planet 2000 as a transport increased the soundstage quite dramatically over the Theta and it sounded grittier, to me, it was more real. The edges were pronounced and not smoothed out like with Theta.

I can't say whether I liked Planet 2k better overall as a transport than Theta. It was different, not sure if overall it was better.

The bottom line is that I was very surprised how much of a difference transports made. Given my experiences, I would not use a $100 player feeding a $1000 DAc. The results will most likely be awful.

 

[GoRedwings19]

Well there goes my idea of using the playstation 2 as a transport and selling my transport

I have tried this when i am bored connecting things up to my Dac to compare.

 

[Glassman]

bifcake, the thing is bits usually don't get lost, this is not a problem with any decent transport (although some DVD players may unintentionaly manipulate the data inside making is non-bit perfect in the first place).. jitter is really just a timing problem, but far from being a problem preventing the data to be transmitted and received bit-perfect.. ideal DAC would sound the same when fed by the same data from any transport, the problem is that vast majority of DACs are not even close to this ideal, but it is technically entirely possible to accomplish.. so the problem with transport+DAC combos can be divided in two: is the transport outputting bit-perfect data? you can check by playing a CD and recording the outputted S/PDIF stream on some decent soundcard, then comparing the recorded file to a rip.. and the second - how sensitive is the DAC to incomming S/PDIF stream jitter? if it's implemented like most DACs are implemented, that is using recovered S/PDIF clock to clock the converters, then this is clearly non ideal, on the other side, if there is buffering done and the converters are clocked by completely independent clocks, any bit perfect transport will sound the same, the difference is just a placebo.. ten kilo mashine 'has to' sound better than a $25 soundcard, well thats just a human's prejudice, technicaly it's nonsense..

 

[bifcake]

Glassman,

How does putting a better clocking mechanism on a DAC work? To me, it sounds like implementing a one sided clock. Shouldn't the transport send out a flag indicating a checksum and another flag for the clock? How else would a DAC know the proper timing implementation? It seems to me that if the sPDIF protocol contained the proper flags (sort of like the Ethernet protocol in computer communications), then all of this would have been a non-issue and all transports would sound the same. However, the way it's set up, I don't see how it's possible to implement one sided clock on a DAC and eliminate timing related issues. Am I missing something here?

Thanks