Differences between CD / DVD player?

[supapimp]

Hello all. I was hoping someone could clarify if there are actual differences between playing a CD on a dedicated CD player or DVD player. If so, why? It would seem to me that since both are digital players, the differences in audio output would be minimal (if any), but I've heard that because CD's use redbook audio, they can sound harsh if played on a DVD player, but I cannot substantiate this. Can anyone provide an explanation?

I have a 2 channel setup and would like to know if I should eliminate my DVD player as the source component and replace it with a dedicated CD player. Would this make an appreciable difference in sound quality with CD's? I'm running RF-7's with a Parasound A23 Amp / P3 Preamp combo, along with a Toshiba SD5700 DVD player. Thank you.

[DrWho]

ya know, I really think that depends on the equipment that you're using. I've heard some dvd players that make cds sound like crap and I've heard others where cds sound great. One rule of thumb would be to make sure that you're using the digital output from the player and then it shouldn't be an issue altogether (my bad experiences were from using the analog outputs). Whenever I demo my system to friends I always put the CD in the dvd player because it has better shock protection...there's nothing worse than a skipping CD.

[scriven]

As Who said, if you are using the digital outputs there should be no difference. In that case both are acting as transports and both should be able to read the CD without error. On analog outputs you are hearing the difference between the digital to analog converters on the two.

[nicholtl]

Well, let's be clear here people.

Just because you're using a digital cable from the CD/DVD player to your preamp/receiver, that doesn't at all necessarily mean it'll sound the same. No sir. Upscale players have superior laser assemblies, master clocks, vibration dampening, transport mechanisms, and less chance of jitter.

But again...all this only noticeably applies to bigbuck players.

[jbsl]

Using the digital out sounds harsh to me I like analog better. Analog to me sounds fuller, smoother more lifelike. Try both and see which one you like better. I have a NAD C542 CD player and a Denon 2900 DVD player and the CD player with a good recording sounds much better than the DVD player. But a bad recorded cd sounds better on the DVD player.

Xman

[consistent]

Hi,

I have gone down that road with my gear and went back to a dedicated CD player simply because the sound appeared (to me at least) better, as I beleive the transport and laser mechanism in a CD is built for sound only. The DVD is a combo but most concentrate on the visuals. However there are some supurb DVD players that have some excellent sound characteristics where most people would not pick up a difference when copmared to a same quality CD player.

Have Fun

[Daddy Dee]

I think your own ears are the best judge. If the particular DVD player sounds good, then stick with it. I've got a perfectly satisfactory DVD player in one of my systems and it sounds very good.

[heresy2guy]

Scriven brings up an excellent point - if you're using analog connections, then it'll essentially boil down to how good the DA converter is.

The one thing that DVD players tend to have now are good DA converters that surpass those of entry level CD players.

About a year ago or so, this was a HUGE topic on many audio forums (including this one) with people harping the merits of the DA converters found even in cheap DVD players from Toshiba and Philips.

I myself bought a Philips and it crapped out on me so I purchased a Toshiba SD3960. Both had 192khz/24bit DA converters.

The difference in sound--compared to my old Yamaha CD player--was astounding. The old gritty, harsh tones were mostly gone (except on extremely bad recordings commonly found in the mid 80s, but even here, they were definitely subdued); the bass was improved; and background noise (hiss) was cut way, waaaaay down.

So the end result was a tremendous improvement in sound for roughly $50 (I bought the Toshiba here in San Diego when it went on sale at Best Buy). The build quality, quite frankly, sucks, and it seems as light and fragile as a feather.

But it sure sounds good.

For how long is another story - lol.

-H2G

[DrWho]

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On 7/12/2005 2:40:58 AM jbsl wrote:

Using the digital out sounds harsh to me I like analog better. Analog to me sounds fuller, smoother more lifelike.

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That simply means that the DAC in your reciever isn't up to par with your dvd and cd players.

I wonder if there isn't some sort of built in EQ with your dvd player because a bad recording should sound worse on it (unless you're saying that there is more distortion with the dvd player that is masking the source, but I doubt that's the case).

[scriven]

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On 7/12/2005 12:08:24 AM nicholtl wrote:

Well, let's be clear here people.

Just because you're using a digital cable from the CD/DVD player to your preamp/receiver, that doesn't at all necessarily mean it'll sound the same. No sir. Upscale players have superior laser assemblies, master clocks, vibration dampening, transport mechanisms, and less chance of jitter.

But again...all this only noticeably applies to bigbuck players.

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Using a digital cable between the player and the preamp means that the digital to analog conversion is being done by the preamp. The digital cable sends the numeric data from the CD to the preamp. The quality of the laser assay, vibration dampening and transport mechanism in the player are irrelevant as long as they are good enough to read the media. The master clock in the player is not being used because the digital to analog conversion is in the preamp.

[DrWho]

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On 7/12/2005 6:24:22 AM consistent wrote:

I beleive the transport and laser mechanism in a CD is built for sound only. The DVD is a combo but most concentrate on the visuals.

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There is no reason that data on a dvd would be read any different than data on a CD. In fact, the only difference between the two is that you can fit more data on a DVD (which requires a more accurate laser). While the data is being read off the CD/DVD, there are bound to be errors that happen and that's where "error correction" algorithms come into play. Essentially, every packet of data on the disc is arranged in such a manner that if read improperly will put up a flag and ask the laser to reread that section. Your player will keep rereading until it finally reads the data right. It works on the same concept as a barcode (like when you purchase stuff) and it's mathmatically impossible to misread the disc (unless of course the player was designed to guess what the data should be and move on...but that's a whole different argument).

So all that to say, the data being sent out the digital outputs when reading a CD with either a dvd or cd player MUST be identical. What it does after it finishes reading the disc is another story, but as long as the data stays digital, then the digital output from the player will precisely match that of the cd being read...and then it's up to the equipment on the other side to deal with the digital signal correctly. There is absolutely no losses or distortion or any problems at all with a digital signal until it hits the DAC, which is why more money should be spent on the DAC than the player itself.

[nicholtl]

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On 7/12/2005 1:17:41 PM scriven wrote:

1) The quality of the laser assay, vibration dampening and transport mechanism in the player are irrelevant as long as they are good enough to read the media.

2) The master clock in the player is not being used because the digital to analog conversion is in the preamp.

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1) I dunno about that, man. Are you telling me you've never heard differences between different players used as transports?? I find that difficult to believe.

2) You're right.

[Frzninvt]

Most CD's played on mid level DVD players sound like crap to me (harsh, edgy and shrill), and NO I don't like the digital output either it sounds kind of lifeless compared to the analog outputs. Must be the conversion to 1's and O's that strips the life from it.

I compare my 1987 DBX DX5 to my Denon 2900 all the time and while the Denon is a very nice player, the DX5 sounds better and it suprizingly will play CD-R/CD-RW's and it does not have a digital output. If I engage the DAIR circuits it easily bests the Denon performance wise.

I will always maintain a separate DVD and CD player.

[scriven]

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On 7/12/2005 2:07:01 PM nicholtl wrote:

... Are you telling me you've never heard differences between different players used as transports?? I find that difficult to believe...

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When using the analog outputs, and therefore the D->A converters in them there will be a difference. When using the digital out - no difference.

[Zealot125]

"Must be the conversion to 1's and O's that strips the life from it."

What are you talking about? You do realise that the data on the CD is in "1's and 0's" to begin with right? all the player does is reads these and sends them directly to the DAC in you preamp/reciever through the digital out. There is no physical variation of these 1's and 0's. The exact same output of 1's and zeros will come out of a denon vs any other name. The advantage of digital out is that there is one less place for conversion from digital to analog. You must understand that conversions=errors. If you insist on using analog out, then PLEASE use strong ATH noise shaping to correct some of the many errors that you have caused in the music.

[Ray Garrison]

scriven,

There are clear and measurable differences in the jitter level detected in the recovered analogue signal when using different transports connected to the same DAC, or different types of digital cables between the transport and the DAC. If you do a search of the Stereophile archives looking for articles related to jitter you'll find John Atkinson has published a lot of measurements using the Miller Audio Research Jitter Analyzer (see here.)

For example, here's an excerpt from his measurements of the MSB Platinum DAC:

"I used the Miller Audio Research Jitter Analyzer to examine the MSB Platinum's rejection of word-clock jitter. The result was very dependent on the datalink used. Feeding the Platinum from my reference PS Audio Lambda CD transport via a 6' coaxial datalink gave a low 197 picoseconds of peak-peak jitter. The spectrum of this jitter is shown in fig.10; it is mainly data-related (red numeric markers), though sidebands at ±15.6Hz (purple "1") and ±120Hz (blue "4") contribute to the measured figure.

"But when I changed the data source to WAV-file playback on my PC, using an RME Digi96/8 PRO soundcard to drive the MSB via a 15' length of plastic TosLink, the word-clock jitter shot up to 572ps. Not only did the primary data-related sidebands at ±229Hz rise alarminglyâshown by the grayed-out trace in fig.10âbut a slew of low-frequency sidebands made an appearance around the central tone. The moral is obvious: Owners of the MSB Platinum need to use a good coaxial datalink and steer clear of the bandwidth-limited TosLink connection."

Here's the image he's referring to:

Whether these differences in jitter levels are very audible, somewhat audible, or undetectable is a different question, but they certainly exist.

Ray

[scriven]

Ray,

That is very interesting. I would not have expected anything that measurable by changing the input source. Looks like I need to do some more research!

[Yesfan70]

I noticed the dB column is in negative values. How "loud" is -120dB or -112dB in relation to the dB reading we see on a SPL meter? A reading of 50dB is very low compared to say 75dB (the "standard" for calibrating speaker levels) or 120dB for a typical rock concert.

As far as DVD vs CD. I like my CD changer better, not because of sound quality, but because disc to disc changes seem to be faster with CD only changers compared to DVD changer. They only have to read one type of disc, the CD. I did consider buying a DVD changer at one time, but settled for my Denon 2200 since it could also play SACDs.

[scriven]

Yesfan,

They are measuring an electrical signal using 0dB (the max) as a baseline signal level. That is why all the values are negative. It is not an SPL measurement so asking how "loud" it is doesn't make any sense.

[DrWho]

Well in a perfect world, dropping the signal on the CD by -3dB should also correlate to a -3dB in acoustical output from the speakers. In real life there are all sorts of non-linearities with the amps and speakers that it may not be exact, but it's pretty close to use those numbers...so these jitter graphs are showing changes which should be inaudible (20dB is the "golden number" for masking).