Will digital CD audio differ from player to player? (1 Viewer)

[Myki Cantero]

Being in I.T., I believe that digital data is just 1's and 0's. So, I believe that it doesn't matter if I use a cheap DVD player or an expensive CD player to play CDs as long as I use the digital out on the player to my receiver. In both cases, the receiver's DAC is used.

BUT... last week, I bought a Nakamichi MB-10 mainly because (1) it was on sale, (2) I want to have a multi-CD changer so I don't have to keep on standing up changing music, (3) to lessen wear-and-tear on my DVD player.

To my surprise and disbelief, the sound is more focused now. The vocals are fuller and more centralized. But why? It's not logical.

Of course, if I use the analog outputs of my DVD player and the Nakamichi for comparison, there is really a big difference. I guess the 96-bit double DAC of the MB-10 is responsible. However, I still prefer using the DAC of the Marantz SR7200.

Can anyone enlighten me please? Or am I imagining things?

 

[george king]

Lots of things go into making different CD players sound different, even when used as a transport. Although the digital out is only passing 1s and 0s, it has to pass them in the right order, with a minimum of errors. So for example, one important variable is jitter, and better transports will have better jitter control.

Hope this helps.

 

[Ken Chan]

Wouldn't it have to be a really lame player to have the bits in the wrong order? Jitter has more to do with timing. Sure, with the proper error correction, you get the same sequence of bits, but the difference between a digit in a spreadsheet and music is that with music, the timing of those bits matter. With CD, it's 44100 samples per second, and if you're a little off, the resulting waveform is different.

//Ken

 

[Myki Cantero]

George, Ken,

Thanks for the info. Do you or anyone in this forum have any actual experience that one player sounds different from another player using the digital outputs? In what way were they different?

Thanks in advance.

 

[ChrisWiggles]

I know that I prefer my NAD 521i to do the D/A converting as opposed to my Marantz sr5300. I was surprised by this actually, but it has a little fuller bass, and seems more "there." I had always assumed that the receiver would have better dacs. More powerful, yes, but also different, and better or not, I prefer the ones in my cd player. That being said, it's a pain in the rear jumping around on a disc, because the NAD misses about the first half-second of every song, and on some discs this can mean the first note which is quite annoying.

 

[Lee Scoggins]

So for example, one important variable is jitter, and better transports will have better jitter control.

In addition to output filters and many other variables, this jitter issue has historically been shown to have a great effect on sound. My recording team and I are creating a new test CD with jitter varied from 200ps to 20ps to demonstrate how important these minute time changes are to the final sound.

The best way to think of it is this:

"Bits are bits, only if they arrive at precisely the right time."

Any variation creates a smearing effect on the sound.

 

[KeithH]

Myki, players can sound very different when used as transports due to various differences in build quality (power supply, transport, jitter, etc.). I once compared a Sony CDP-CA80ES carousel changer and a Pioneer CLD-D406 laserdisc player as transports in a mid-fi home-theater system (Sony STR-DB930 receiver and Energy e:XL 16 speakers). The 'CA80ES was far, far better as a transport. The 'CA80ES was detailed and layered, while the 'D406 sounded muffled and lifeless.

 

[Ryan Tsang]

I took your post as a challenge to do a faceoff this morning.

Arcam Alpha 7 cd player vs Onkyo DV-C501 DVD changer as transports. The Arcam used a coax connection (Audioquest Digital Pro cable). The Onkyo used a toslink connection (Ultralink cable). Both units connected to an Acurus ACT-3 and were level-matched.

The differences were not drastic, but the Arcam was better. Top end was smoother, more refined. Bigger differences were noticeable in the bass dept. The Onkyo was thicker and muddier, whereas the Arcam's bass was clearer and more defined. It easier to tell (and feel) on the Arcam the individual thump of the drum machine on Leftfield's Leftism. On Delerium's Poem, the muddier bass of the Onkyo sweared into the female vocals. Realistically, I could live with either one. It's difficult to tell unless you are critically listening in the sweet spot.

But the real suprise this morning was provided by a tweak. Non-believers can start laughing now. The rest are invited to read my post in the tweak forum on Black Diamond Racing Cones.

 

[KeithH]

Ryan, a priori, I would have expected the Arcam player to serve as a better transport. However, to due to the test properly, one really needs to use the same type of digital connection on both players (coaxial or optical) and the same make and model of digital cable. In your case, this may not have been possible, and I can't say for sure that it would have made a difference. Yet, you still can't say for sure that the difference in connections and cables did not influence the results.

 

[Ryan Tsang]

Keith:

I understand where you are coming from. The arcam only has coax out and the onkyo only has toslink. Without question, the players, the output format, and cables all contribute to differences in sound. The question is, how much is each variable introducing, and is the increase in performance worth its expense. For example, is a player $300 more using a run-of-the-mill digital cable better than a cheaper player using a $100 digital cable? Which variable affects sound the most? Transport I'd say. But I think subtle differences like that comes down to not whether one is better than the other, but one is simply different and you choose the style that fits your taste.

If one doesn't believe in cables or diffs between coax and optical, they have to believe that transports make a diff. OTOH, if one says spinning a disc is just spinning a disc, then cables must do something. Either way, digital is not just digital. but you knew that already

 

[KeithH]

Ryan, those are all good questions. It's hard to say the influence of the cable. Of course, it depends on the relative quality of the cables you are comparing and the transparency of your system. In the end, I would fully expect your Arcam CD player to serve as a better transport than the Onkyo DVD changer regardless of cable type.

 

[Ian Montgomerie]

If you did a blind test you'd quickly realize there was no discernable difference. The mind can be extremely deceptive about sound quality when it knows what it is listening to and when.

 

[KeithH]

Ian, yeah, O.K. Thanks for sharing the "knowledge". I love it when people who don't believe in something assume that other peoples' observations are purely psychological. :rolleyes

 

[Myki Cantero]

Ok. Now I tend to believe that transports can still be different with each other but the perceived difference would depend from system to system and that the whole equation comes into play on what connectors, etc. are used.

I'll try to do a blind A/B test so I could validate this. I'll make 2 copies of a CD, play it on both transports, and ask my wife to change the source for me while blindfolded.

If I can't discern which is which, then at least I know that with my system... it doesn't matter what transport I use. Maybe my budget B&W 601 S3 speakers can't produce enough detail for me to notice a difference.

Myki

 

[Ian Montgomerie]

I love it when people who don't believe in something assume that other peoples' observations are purely psychological.

I'm an engineer who has done a fair amount of low level work with digital audio and has a good understanding of how it works. In technical terms, there is very little difference between transports. This is no accident - the entire nature of the digital technology involved, is aggressively designed to eliminate any differences in the audio output from the exact details of the media, the disc drive reading it, the cabling, etc., etc. A very few things associated with the transport - such as its master clock jitter - can lead to differences on the output that are measurable with extremely sensititive equipment. But not at all easy to discern by ear. Many other factors that people worry over, such as the type of digital cable one uses, are provably irrelevant by the very nature of the technology.

Various blind tests have in fact been done in the audio industry. Unsurprisingly (to someone who knows the technical details), it turns out that people who think differences from transports, cables, etc. are "blatantly obvious" in non-blind listening, are often completely unable to pick out those same differences in blind testing. I have personally experienced this - sometimes I thought I heard big differences between certain components, but all of a sudden it was an entirely different matter when I didn't know which was which. Subjectively, our minds can even greatly exaggerate real differences. For example, MP3 files obviously discard some quality compared to an uncompressed audio source. But when I put some .mp3 and .wav files of the same song in a random playlist and close my eyes, I find that I actually have a lot of trouble telling the difference between a high bitrate MP3 and the original file.

Given my practical knowledge that people in non-blind listening conditions greatly exagerrate differences in audio quality and can think they hear differences that aren't there... plus my technical knowledge that it is basically impossible for there to be differences where some people think they hear them (e.g. digital cables)... you are darn right I assume such observations are purely psychological. It's the only reasonable position to take.

 

[Ian Montgomerie]

It also doesn't help that even when actual differences may exist, they're not the ones people claim to hear. For example, people claim that a better transport can produce "warmer, fuller sound". But bit errors manifest themselves as annoying clicks and pops, and jitter manifests itself as irregular distortion.

 

[ChrisWiggles]

Well, I dunno bout you guys but the difference in transports is like night and day. My one player sounds green, and the other fuller, and rich with the texture of peanut butter. A player I heard at the store had a tone with more resolving and the color of ping flamingos.

 

[Ryan Tsang]

sniff...sniff...I smell sarcasm.

I don't think the difference is night and day at all. In fact, I said it was difficult to tell, unless you're listening critically in the sweet spot.


Ian:

I totally agree that the mind can be highly suggestive. I tried to remain as neutral as possible because I had no reason to favor one over the other. In fact, I wished the DVD player was better because if it was, I could sell my cd player. If you read my post on BDR cones in the Tweak forum, you would know that I don't claim to hear diffs in digital cable, power cords, and such. If my mind was playing tricks on me, I would have wanted the Onkyo to "win" but it didn't.

Seeing that you are an engineer, can you explain why isolation can make a difference? And please don't say it doesn't because some of them do.

 

[ChrisWiggles]

I can definitely see how different transport mechanisms can be better, and I am a firm beleiver in quality interconnects, although I am skeptical of speaker wire differences (at least I haven't heard any differences yet) and I am skeptical of differences in digital cables given that they are of at least entry-quality design. I am also a FIRM beleiver that speakers sound different. Just saying, I actually get that a lot from non-audiophile friends "well, all decent speakers will sound the same." Bah.

I remain skeptical of a lot of things, but I am open to new ideas always. Fuzzy reasons rarely work though. The cd stickers and green marker etc. seem like bunk to me, but who knows. Some people swear by wire isolation. Again, who knows? I figure, if you have a system THAT nice, why not spend a couple extra bucks if it makes you feel better. After all, even if the improvement you are hearing is totally psychological, it still sounds better to YOU, and that's all that matters. And even if I sound nuts, I always listen with the lights off. Is it to reduce noise and interference from em spectra and dark-energy generated by my dimmer switches? No. It's less visually distracting in the dark, and things seem to come alive, and it's a lot easier thatn holding my eyes shut. I also cover my light-switches in glow-in-the-dark paint. No, not so that the inherent properties in glow-in-the-dark paints block RF anomolies generated by the abrupt circuit end at the switch, but so that I can find them in the dark when i'm done.

Anyone besides me still use an 8-track player as their reference source? I'm with Ryan on this one.

 

[LanceJ]

I just wrote part of this on another thread, but it still fits here :

Analog audio quality can be quite variable & is determined by the design and parts quality of the player's analog output stage.

If it uses integrated circuit chips for amplification, the sound can be pretty darn good (30+ years of IC development has helped!). And is extremely inexpensive for the manufacturer to install.

But for best quality, it's best to use discrete parts, i.e. separate transistors, capacitors, etc. And if desired, they can be hand-picked for optimum circuit cohesiveness (synergy?). And, a designer can design into the circuit whatever sonic "signature" he wants--warm, neutral, bright, whatever. This is sometimes called "voicing" a component.

Check out these two photos of two different Philips sacd players at AudioAsylum. One is built just a LITTLE bit better : http://www.audioasylum.com/forums/h...ges/123423.html

The filters in a digital-to-analog converter can alter the sound too. This is why many expensive CD players use 192kHz converters--these use more "gentle" filters that produce less sonic artifacts in the audible region.

And the best DACs are usually the multi-bit, resistance-ladder type, but these are expensive to manufacture (a laser is used to precisely trim each resistor so it produces exactly the right voltage for each part of the analog waveform). 1-bit converter types are much cheaper to make but not quite as precise.

Jitter? 99% marketing hype. When something is measured in trillionths of a second??? And I have yet to see a proper listening test conducted for this so-called "problem".

The analog output stage is still (IMO) much more important in determining a player's sonic quality than its digital stage's effects.

LJ