If the DAC is the same, how different do CD transports sound?


One interesting topic of discussion here is how audible the differences are between CD players when they are used as transports only — or when they are only transports to begin with.

In other words, in a comparison which keeps the DAC the same, how much difference can be heard between CD transports?

This recent video by Harley Lovegrove of Pearl Acoustics provides one test of this question. It may not be the ultimate test, but he does describe the experimental conditions and informations about the qualifications of the listeners.

He comes to the main conclusion here: https://youtu.be/TAOLGsS27R0?t=1079

The whole video is worth watching, I think.

128x128hilde45

Yes, two different CD transports will sound different!

Any DAC clock recovering circuit has own problems, such as PLL overshot, BW, stability, phase margin, etc. Less clock impurities, aka jitter, in input signal will result in higher accuracy sound.

I haven't watched the video yet but I will later on.Thanks for posting it. I used to have a Vincent (tubed) CDP which I was extremely happy with. It wasn't as resolving as my current equipment,but after some tube rolling I had no desire to ever upgrade. When it bit the dust it was replaced with a CXC and Tubadour, which being quite a bit more resolving and transparent sent me down the path of attempting to working harder on room acoustics,vibration control,etc. since the issues I had were now unmasked. I'm not sure if that was a good thing, lol.Once again I'm completely content with how the music sounds which is several steps above where it was a few years ago.Hopefully nothing breaks so I'm not tempted to upgrade and start the dominos tumbling again. I've considered trying a better/different transport but talked myself out of it several times.

Once you hit a certain level of transport and DAC coupled with very clean amplification, good cabling, speakers, etc...the differences are pretty easy to hear.

Listening and comparing a couple sub $1000 transports probably won't tell you much.

 

@hilde45 don’t take it the wrong way, but I think you are too excited to see the conclusion of that video aligned with what you were hoping to hear. In other words you had a biased opinion going in and now it impairs your ability to keep an open mind.

Your argument on why the number of views matters is pretty weak as well. Whether it’s 94k views or 2mil views doesn’t reflect on validity of the message in that video.
If we use number of views as an indication of how valid the information is, then Barbie was and still is a more important historical figure than Oppenheimer.

Re the comments about fast vs slow switching in A/B testing. When I was at university I was involved in many A/B/X listening tests. The point was not to say which sounded better, but rather to say which of A or B was the same as X, which was randomly chosen. If a listener cannot reliably identify X as either A or B, then they can't tell the difference. While subjects were free to switch as frequently or infrequently as they liked, they invariably started to switch back and forth more quickly as the test proceeded.

Our auditory memory for fine acoustic details is relatively short, and people seem to recognize and compensate for this.

Post removed 

@coralkong

 

Once you hit a certain level of transport and DAC coupled with very clean amplification, good cabling, speakers, etc...the differences are pretty easy to hear.

Listening and comparing a couple sub $1000 transports probably won’t tell you much.

So the sub $1000 transports pretty much sound the same? Even on a system with very clean amplification, good cabling, speakers, etc.? That’s quite an accomplishment in consistency it would seem. I’d get the impression that the bad transports would sound much more different in their various flaws, while the more perfected transports would become increasingly difficult to tell apart as they approach perfection.

It’s conceivable that the cheap transports all have pretty much the exact same flaws, and it’s only when somebody makes an attempt to get past those practically uniform flaws that the differences become apparent. Each maker uses different approaches and gets slightly different results, but all are better than doing nothing at all. Maybe it’s kind of like adding coatings to lenses to reduce color abberations and glare. One maker might use a coating that looks blue, another purple, or orange. They all give slightly different results, but all are better than just leaving the lenses uncoated, which would be cheaper and perhaps fine for a lot of users.

I think the coated lenses analogy is pretty good, and one that I can relate too in my recent experience. My previous glasses had coated lenses. My newer ones do not. There is definitely a difference, but for the most part I’m seeing things just as good without the coatings as I was with them. Uncoated lenses are worthy of the best frames you might want to get with them. I’d also argue that a cheap transport is worthy of the best sound systems out there. Whatever a cheap transport’s shortcomings are, it’s never going to be the weakest link in any sound system, unless it’s just downright malfunctioning, or makes too much mechanical noise.

@asctim ,

Perhaps I am making the assumption that if someone is looking at a sub $1k transport, they're probably using a sub $1k DAC as well......so, point taken, I should have been more clear.

Now, that being said, if you start talking about using.....say.....a $5k+ DAC, the differences between a $600, $2500, a $5k and a $10k transport will be much more discernable.

In my room, paired with Aqua La Voce S2, Jay's CDT2MKIII transport yields far more detail and noticeably more bass than Sim Audio Moon 260DT transport. I found the degree of  improvement disproportionally high, given the price difference. Whether this is typical or atypical, I've no idea. 

 

@audphile1

don’t take it the wrong way, but I think you are too excited to see the conclusion of that video aligned with what you were hoping to hear. In other words you had a biased opinion going in and now it impairs your ability to keep an open mind.

You might be right. I’m going to accept your take as a reasonable hypothesis and reconsider why I’m posting this. The funny thing is, I have disconnected my CD transport because I’m not using it very much. I stream all the time. So, I’m not that motivated to keep what I have vs. upgrade. I find the question theoretically interesting and two audiophiles I admire for their acument (including @jjss49 ) make the same argument as the video. So, if I’m biased, it’s because the people I respect for their knowledge agree with the video, not because I have a dog in this fight.

Your argument on why the number of views matters is pretty weak as well.

I really botched explaining it. My apologies. Here’s another way to look at it. If you were on a youtube video accidentally slipping on a banana peel, would you want it to have 93k views or 10 views? Probably 10 views, because no one wants to be embarrassed. The same idea holds for those mentioned as participating in this review. He names them here: https://youtu.be/TAOLGsS27R0?t=528

If they have reputations they want to protect, then if the experiment in which they’re mentioned is a shoddy one -- with 94k views -- that works against them. That’s the best I can phrase the argument, but I’m happy to agree to disagree on this one.

Based on personal experience with both CD players and ripping CDs I suspect if or when a significant difference exists it is most likely due to how the player handles poor quality CDs that take longer to get the data off than good quality CDs.

For example I rip CDs using your basic usb CD drive. Poor quality CDs take much longer to rip with no errors, but eventually 99% of CDs do rip with no errors.

 

Thing is you CAN NOT tell a good quality CD from a poor quality one by just looking and the quality can vary to a great degree.

Meanwhile playing a CD requires the data be read fast enough to keep the music going. Lots of things can go wrong if the data is not buffered to faster more reliable storage before going through the D 2 A process.

So to me playing a CD is a bad idea and lots can go wrong. Some players are surely better than others. It’s not rocket science though so no need for a reliable CD player to cost a huge premium.

That means I always rip my CDs once then stream them. I never use a CD player anymore. It just makes sense and provides a greatly enriched user experience once a CD is ripped to disk in a music library.

My advice: Join the 21st century. Just rip and stream. I use dbpoweramp software to rip which does a very good job of providing accurate rips. Any decent computer CD drive will do and cost very little. Keep a CD player around for an emergency perhaps, if you must. I do but have not used it in years.

 

Mapman,

I agree with you about ripping and streaming.  I utilize a Naim UnitiCore to rip and store my CDs as WAV files (it has a built in 8tb hard drive).  Of my 5,000 CDs, only four could not be ripped because the CDs also had video content.  Like you, I have noticed that some CDs take MUCH longer to rip because they have parts that have to be read over and over for error correction.  The ripper reports the number of errors that required interpolation to fill in error gaps.  Of these 5,000 CDs, the ripper has found zero errors requiring such measures.

The ability to search for any CD by knowing the tiniest bit of information, or browsing the collection by genre is priceless, particularly with a large collection.  The convenience of not having to search for each CD and then having to re-file them when done is also great.  The fun of assembling long playlists is also not to be overlooked.

Hi all, I bought a ProJect RS2T for my Border Patrol Dac. Never had anything else to compare, as I'm more into analog and just wanted a good transport under 2.500 eur (I live in Poland) without visiting 20 dealers and here for 2.000 eur you can get a ProJect. But I tell you something, I used to have also the ProJect power supply, the RS BOX UNI 1 Way and later I sold it for very decent money. Then I decided to plug a new power cord into the Dac. I had for one year a Cardas Parsec, when I ordered from Pete a Triode Wire Labs' High Power Digital American power cord. It was night and day. I have no longer the power supply so I'm using the stock one, but anyway the sound it's much better than before, just with the new power cord. Like listening to a different Dac or amplifier. Same with analog system, when I plug Pete's power cord into my Leben CS300F the sound becomes dramatically better, more structured highs and bass, more depth, more details, voices much more present and "human". So for my personal experience cables do make a different, in the case of this power cord a terrific difference. And that's what I suggest to get the full potential from your equipment.

adversam

What does it have to do with this post subject "If the DAC is the same, how different do CD transports sound?"🙄

I dont stream , and i dont use cd transport anymore... Only a battery dac with an internal lossless files bank... Less noise and simpler... I am lucky.. 😊 I transfered all my cd from the last 25 years... I invested in music much more than in my audio system... *I could not do the two...

Interesting thread anyway...

Maybe someone someday can do a deep dive on source to dac issues and come up with some good explanations and examples of what can go wrong. I’m convinced that weird things can go wrong even though the music keeps playing. I’ve heard it myself ; strange and obvious distortion that somehow creeps into the signal chain, and it’s source is in the digital domain. A re-start usually fixes it. I’ve always experienced these anomalies when I’m feeding the digital signal in some kind of daisy chain of devices before it reaches the dac. Some things I think I understand, like when one device is set to 44.1 and another to 48 kHz. You get the playback speed varying all over the place to keep the two devices in sync. Other issues I’ve heard are high distortion, making me think a coil is rubbing. A flute sounds like a kazoo. I’ve also seen video artifacts creep in through fully HDMI connections, where I see a slight ghosting until I unplug and re-plug the HDMI cable. There’s so much processing going on between these devices that opportunities for a corrupt but playable signal can happen.

It will be affected by how clean the digital signal is from the transport to the dac.

 

Most deniers are oblivious to the fact that the “digital signal” going over a wire from transport to dac is an analog signal representing the digital data. Noise on this analog signal caused by a poor transport or bad cable will infiltrate the dac. better dacs can filter some of the noise but filtering is not perfect because electrically everything inside the transport and dac are connected. Nothing is perfect but some equipment and cables are better than others. 

Wanted also to add this factor for transport differences…

 

the optical laser detector inside the transport is an analogue electronics device which is changing its output continuously as the laser light dims and brightens. 
 

Electronics on the pc board later determines if it a 1 or a 0 based on the analog electrical signal from the laser optical reader and sets 1 or 0 based on a threshold. 

Where I am going with this is that another source of electrical noise in the transport is noise that the optical laser detectors is picking up between the high and low points reflections of the CD aluminum pits. This is “light noise” between the high and low reflection signal and is the scattered laser light inside the transport enclosure. 

Everything is connected electrically and better transports will filter this noise from from the optical sensor from getting into the signal path. No filter is perfect but they can reduce noise.

 

this is why darkening the edge of a CD with a marker pen can improve sound reproduction by reducing the scattered light inside the transport which reduces the “light noise”.

 

if you followed this and have a resolving audio system would like to hear back if you can try use a dark marker on a cd edge and listen for differences.

 

I can on my mid level high end system though I mostly stream now.  

 

My CD 'player' is a network drive where I keep my digital music.  Will we have to start doing comparison A/B tests with different brands of hard drives?  Has anyone actually done that?

I’m a little late on this thread, but going back to OP’s original question -

I have been using a dedicated transport to drive a DAC. I got out an old(er) CDP of the tubed variety, but I drove the DAC with the digital output which bypasses the tube section (of course!). The difference was substantial which kinda surprised me as the dedicated transport gets high reviews for a, relatively, inexpensive transport. The dedicated transport (an Audiolab) had a very good but somewhat clinical sound, whereas the CDP (a Raysonic) sounded like it had tubes (but it didn’t, they were removed), a much smoother, full bodied sound. The signifies not much except it certainly displayed a clear difference.  I much prefer the old CDP for the CD I was playing, an older, laid back, jazz piano piece . I guess it pays to keep an open mind on this subject. 

Oh, FWIW, all wires were the same for both units.

 

sudnh

"the optical laser detector inside the transport is an analogue electronics device which is changing its output continuously as the laser light dims and brightens."

This is revolutionary theory indeed. Why is then a DAC (digital to analog converter) needed if a laser provides analog signal?

For most of the history of CD players there have been only a few transport manufacturers… but CD players and transports sounded quit different with the same transports. Companies that wanted to get the most out of sound would go through extraordinary feats to mechanically and electrically isolate the drives to perform their best. And it works.

 

This is why, although CDs are waning in popularity there are still a number of high quality transports out there. 

If a DAC is good enough, it buffers by storing bits and releases them in a precise enough clock, the bits just before conversion should correct inaccuracies in most transports. It becomes hard to hear the difference between the transport and a file in a storage device. 

I tried over a dozen, from highly rated DVD players, inexpensive audio transports to the latest PS Audio expensive transport.  I chose a fully upgraded/moded Arcam Delta with a new transport mechanism.  I had to upgrade the resistor fuse twice and double it's rating as two different boards blew and had to rebuild.  Otherwise, I would choose a Jay's Audio CDT3/M3 for $5,000.  The digital cable also makes a difference although I only tried 5, I'm keeping the Synergistic Research Atmosphere Euphoria X, best bang for the buck and only SR cable I own. 

Gentlemen - I usually refrain from contributing to such post but I'm compelled to do so this time.

First - a system has to be of high fidelity to be able to distinguish the differences of anything. The system includes equipment, it's set up and the room acoustics.

Second - EVERYTHING matters. Everything!

I switched transports, from a Meridian 800 transport to a Oppo 205 used as a transport. In both cases, a $4,500 (retail price) MIT coaxial digital cable was used. The Meridian sounded natural and dimensional with a wide, deep soundstage.

The Oppo sounded thin, artificial and lacked any dimensionality. Also, the bass was significantly compromised.

I usually state anyone is welcome to come listen for yourselves but my system is not operating because my wife issued me a divorce, which we're in the process of completing.

Jasonbourne71 - when I get my system operational, I'll offer to pay for your transportation and lodging to come and listen to my system if you agree to post your experience. Friends told me not to do it because you would be biased. I enjoy sharing good music and would enjoy experiencing your reaction - no matter what that reaction may be - because I'll gain insight to individuals. You'll either clearly hear a dramatic difference or your won't.

To be completely honest - I'll also have others present during the demonstration who will select their favorite and describe and write down what they hear for each session, so it will be a collaborative effort. And, of course - it will be a blind listening test with a variety of things switched in random but documented order.

I guess I must add my 2 cents. My system (large acoustical area and 80 to 90 db Rock and Roll only) Pass x250.8 (running in Class A) Tekton Double impacts upgraded, SVS Sb 4000 sub, Meitner MA1 V2 DAC, Project RS2T transport, all decent cabling, nothing outrageously priced. Also a Benchmark LA-4 pre- amp, all Balanced.

I had started with a Benchmark 3B DAC and a Audiolab 6000CDT. Sounded very good. Then I upgraded the DAC to the Meitner, refined jump upwards! (ps still have in another system the Benchmark DAC, which I still like a lot) Then I added the Project RS2T, with upgraded LTA power supply, what a DIFFERENCE, not just 5 or 10%, every bit MUCH more. I was astounded. How could this be! Keep in mind some CD's sound better than others, mastered better I guess? Huge difference. See reviews from other owners of transport on Audiogon forum.  I also stream qobuz and it's amazing as well. Qobuz is still  (High REZ) a step up in resolution and dynamics over the CD, but, with the Meitner DAC and the RS2T it is so close, sometimes not being able to differentiate. Makes listening to CD's great.  It's that good. Very Very evident!!! Robert TN

@jasonbourne71 @robshaw

What went down? Any plans here for jasonbourne to find the truth? Quite a generous offer for him.

Related to this thread, to evaluate the difference a simple transport makes does anyone recall ever going to a Linn dealer 20 years ago and hearing the difference between the Genki and Ikemi cd players? Those had identical power supplies and chipsets: the only difference was an off the shelf Philips transport in the Genki, and a Linn produced proprietary aluminum transport for double the retail price of the Genki (and balanced outputs) for the Ikemi. Absolutely one could hear the additional resolution the transport in the Ikemi provided, by swapping one for the other in the same setup (using RCA’s) , but personally I didn’t have the extra money to buy the Ikemi 20 years ago so I had to settle the Genki and enjoyed it for well over 10 years. I don't have any Linn equipment anymore, but the word is still in my forum handle name :( 

I'll add a more detailed answer than I did before.  

CD transports do not do any file conversion or format changes that can color the music.  so it is all about implementation.  

The data on a CD is very dense so the mechanical components to read them have to be good.  that said, mass production has resulted in readers that can do it for $20.  So it all comes down do accuracy:  are they dropping bits and are they introducing jitter/clocking errors. 

Challenges include mechanically imperfet discs, wobble, speed control (the reader has to vary rotational velocity as the disc is read from inside to out), and laser control.

Bottom line is, a well made CD transport minimizes all of these but obviously there is less to be gained here than in , say, a DAC where there is tremendous opportunity to add color (or whatever you want to call it) to the music.  In fact, it may be impossible not to.  So focus on the DAC first.

Jerry