Identical DACs, identical sound?

[Buckle-meister]

Dear all,

The other day, I asked the question "Assuming that the DAC in both AV amp and DVD/SACD are the same, will the sound be 100% identical?" The answer returned was that yes, they should be.

After some thought, I have a few further questions. However, let me first put things into context. My current HT system comprises:

1. Yamaha DSP-Z9 AV amp.
2. Mission Elegante 5.1 speakers
3. InFocus 5700 DLP projector
4. Budget priced DVD player.

I am well aware how out of place my DVD player is in comparison to the rest of the system and that is why, for the last half year, I have been (impatiently) awaiting the release of Yamahas S2500 DVD/SACD player.

My intension was to use the new player for DVDs, SACDs AND CDs (I have experimented with my Musical Fidelity Electra E600 CD player/ Z9 amp and find the amps DAC, perhaps not unsurprisingly, to give me a more detailed sound) However;

1. Given that the Z9 has the best Burr-Brown DACs currently available, why would I (specifically) or anybody else (generally) consider buying a top notch dedicated CD player (something I had planned for the future)? ie, if my amp has such good DACs, why dont I just buy a totally cheap CD player and use the amps DAC? Does the quality of the CD transport make a significant difference?

2. Even though the sound would sound the same if both DVD/SACD player and amp had the same DACs, surely that is not the end of the story? For example, nobody would argue that the sound of different manufacturers amps have their own distinctive 'sound'. So even if the sound is identical immediately after the DAC converts to analogue, wont either the player or amp then 'shape' the sound according to the electronics inside each box respectively?

 

[mtrycrafts]

Dear all,

The other day, I asked the question "Assuming that the DAC in both AV amp and DVD/SACD are the same, will the sound be 100% identical?" The answer returned was that yes, they should be.

After some thought, I have a few further questions. However, let me first put things into context. My current HT system comprises:

1. Yamaha DSP-Z9 AV amp.
2. Mission Elegante 5.1 speakers
3. InFocus 5700 DLP projector
4. Budget priced DVD player.

I am well aware how out of place my DVD player is in comparison to the rest of the system and that is why, for the last half year, I have been (impatiently) awaiting the release of Yamahas S2500 DVD/SACD player.

My intension was to use the new player for DVDs, SACDs AND CDs (I have experimented with my Musical Fidelity Electra E600 CD player/ Z9 amp and find the amps DAC, perhaps not unsurprisingly, to give me a more detailed sound) However;

1. Given that the Z9 has the best Burr-Brown DACs currently available, why would I (specifically) or anybody else (generally) consider buying a top notch dedicated CD player (something I had planned for the future)? ie, if my amp has such good DACs, why dont I just buy a totally cheap CD player and use the amps DAC? Does the quality of the CD transport make a significant difference?

2. Even though the sound would sound the same if both DVD/SACD player and amp had the same DACs, surely that is not the end of the story? For example, nobody would argue that the sound of different manufacturers amps have their own distinctive 'sound'. So even if the sound is identical immediately after the DAC converts to analogue, wont either the player or amp then 'shape' the sound according to the electronics inside each box respectively?

Why not just keep the DVD, play your Cds on it and use the digital ouput. Problem solved.

 

[Buckle-meister]

My reasons for changing my present DVD player to the new Yamaha are:

1. The video DAC in the yamaha will almost certainly be better than that of my budget DVD player.
2. I will be able to take the HDMI-out directly from the Yamaha player to my DLP projector. At present I use component leads.
3. I will be able to listen to SACD/DVD-A which at present I cannot.

These are sound reasons for purchasing the new Yamaha in terms of DVDs and SACD/DVD-A, however, my question was not directed to at these; it was with regard to CDs.

Plenty of people must have bought a top notch CD player in addition to an amp with DAC capability. All I am asking is:

1. If the sound is the same using either the player or amps DAC, then do all those people simply have too much money to burn?
2. Does the quality of a CD transport make much of a difference to the final sound that we hear?
3. Isnt it irrelevant whether or not identical DACs give identical sound, since the rest of the electronics in either a CD players or amps box must further 'shape' the sound in its own distinctive way?

Cheers

Robbie

 

[MDS]

Plenty of people must have bought a top notch CD player in addition to an amp with DAC capability. All I am asking is:

1. If the sound is the same using either the player or amps DAC, then do all those people simply have too much money to burn?
2. Does the quality of a CD transport make much of a difference to the final sound that we hear?
3. Isnt it irrelevant whether or not identical DACs give identical sound, since the rest of the electronics in either a CD players or amps box must further 'shape' the sound in its own distinctive way?

Cheers

Robbie

Since nobody has responded directly to those questions, I will:

First you have to distinguish between using the analog vs digital connections. As said before, when using the analog connection it is the player's dacs that are used and when using the digital connection it is the receiver's dacs. So the answer depends on the type of connection.

Using analog connections, the quality of the transport would come into play; ie can the player read the digital data off of the cd with the correct timing so that the data fed to its dac is accurate and free of jitter (jitter is a TIMING error). This is where you will get the argument that high quality (ie expensive) players can be superior because they are presumed to have superior transports. IF the transport is indeed superior and/or the player also uses a buffer to correct for small timing variations then it could be better than a different player that does not. That is where you could say that a given player imparts its own character to the sound.

The reality is that they all do and arguments about the quality of a given transport is far superior to another is mostly fallacious. Remember we are assuming the dacs in the player and receiver are the same so there is no difference attributable to the dacs - only a difference in getting the data to the dacs with the correct timing. Even cheap cd/dvd players have jitter on the order of picoseconds (trillionths of a second). The jitter debates rage on but for the most part it is irrelevant. Jitter can never be totally eliminated but the levels in modern electronics is so low that it isn't worth worrying about.

When using digital connections, the quality of the transport is irrelevant because the data will be buffered and re-clocked on the receiver side. Given identical dacs there will again be no difference in sound quality that could be attributable to the dacs.

So yes, I think buying an uber expensive player on the premise that its 'transport' is better is wrong headed.

Now if you want to spend huge sums of money for bragging rights...so be it, but there is no other reason.

 

[Buckle-meister]

Thanks where thanks is due

Thank you my friend,

For a moment, I thought I had asked some kind of taboo question!

kind regards

Robbie

 

[mtrycrafts]

Using analog connections, the quality of the transport would come into play; ie can the player read the digital data off of the cd with the correct timing so that the data fed to its dac is accurate and free of jitter (jitter is a TIMING error). .

I am sure this is immaterial as the digital data goes to a buffer on all CD players and gets reclocked.

If it was wrong, then it would also matter if the digital signal is sent on the the receiver.

 

[mtrycrafts]

My reasons for changing my present DVD player to the new Yamaha are:

1. The video DAC in the yamaha will almost certainly be better than that of my budget DVD player.
2. I will be able to take the HDMI-out directly from the Yamaha player to my DLP projector. At present I use component leads.
3. I will be able to listen to SACD/DVD-A which at present I cannot.

These are sound reasons for purchasing the new Yamaha in terms of DVDs and SACD/DVD-A, however, my question was not directed to at these; it was with regard to CDs.

Plenty of people must have bought a top notch CD player in addition to an amp with DAC capability. All I am asking is:

1. If the sound is the same using either the player or amps DAC, then do all those people simply have too much money to burn?
2. Does the quality of a CD transport make much of a difference to the final sound that we hear?
3. Isnt it irrelevant whether or not identical DACs give identical sound, since the rest of the electronics in either a CD players or amps box must further 'shape' the sound in its own distinctive way?

Cheers

Robbie

I thought that I gave you the correct answer, use the existing DVD player for CD and let the receiver do the DA conversion. If it mattered I would have given a different response. It doesn't.
But, now that you need other performance from a DVD player, get the newer one that meets your need and use that for the CD playback as well.

There is too much made of a nothing event, playback of a CD.

 

[Jazzwyld]

DAC aren't all the same

If you check out a few manufacture DAC's, such as Burr-Brown or AKM you will find out they are not all the same. They have different bandwidth and bit depths. This in turn does play a sonic difference, it is similar to listening to a CD or an MP3, a drastic comparsion, but one DAC that has x amount of SN ratio compared to one that has less there will be a difference. Another thing to think about is the electronics, you can have the same DAC and have a different sound quality. Theta Digital uses BurrBrown and so does NAD, and no one would ever confuse the two of sounding the same.

 

[Jazzwyld]

Digital Outs

Just a comparison a customer of mine took home the Yamaha DVDS-1500, he has a Sony DVD player cost around $99, was blown away by the audio and the video and he was using the digital out, if you are looking for a great little player and not wanting to spend the money on the DVDS-2500 which is now available. You won't be sorry you bought the 1500 at all.

 

[Buckle-meister]

I thought that I gave you the correct answer, use the existing DVD player for CD and let the receiver do the DA conversion. If it mattered I would have given a different response. It doesn't.
But, now that you need other performance from a DVD player, get the newer one that meets your need and use that for the CD playback as well.

There is too much made of a nothing event, playback of a CD.

I have to disagree I'm afraid. I am stunned by the picture and sound from my HT kit, but let me be clear; I am a music lover first and foremost, so I certainly do not consider playback of CDs as nothing events.

Any way that I can squeeze more from a CD is of interest to me, and whilst my questions may be trivial, the answers I recieve to them may just prevent me from needlessly wasting my cash.

Regards

 

[Buckle-meister]

If you check out a few manufacture DAC's, such as Burr-Brown or AKM you will find out they are not all the same. They have different bandwidth and bit depths. This in turn does play a sonic difference, it is similar to listening to a CD or an MP3, a drastic comparsion, but one DAC that has x amount of SN ratio compared to one that has less there will be a difference. Another thing to think about is the electronics, you can have the same DAC and have a different sound quality. Theta Digital uses BurrBrown and so does NAD, and no one would ever confuse the two of sounding the same.

That last sentence; thats what I was talking about!!

Regards

 

[WmAx]

.....If you check out a few manufacture DAC's, such as Burr-Brown or AKM you will find out they are not all the same. They have different bandwidth and bit depths.....

....This in turn does play a sonic difference....

How does this relate to audible differences? Please be specific. A flawed conclusion, due to speculation(s), should be avoided when possible.

it is similar to listening to a CD or an MP3, a drastic comparsion,

An mp3? Which mp3? Encoder? Encoder mode(s)? Bitrate? Source material being encoded? With a high quality encoder such as Lame, using the appropriate mode(s), it is shown to be transparent in ABX trials on almost all music program material. The exceptions are limited to specialized test signals and rare occasional problem samples in some music. Don't assume that all MP3 sounds the same: a properly encoded MP3 is excellent compared to the source PCM data.

but one DAC that has x amount of SN ratio compared to one that has less there will be a difference.

In order to reach transparency, one only needs a S/N ratio that allows the noisefloor to be below that of the environment that is used to listen. Realize that a very quiet, specially built room, may achieve a 30dB noisefloor on a good day(no traffic or lawnmowers, etc.). Now, calculate the SPL ability of the speakers at the listening position with reasonable levels of distortion. This will be in the <110 dB range for most full size speakers(typical exceptions being line arrays and horn speakers). In this optimal room/conditions, an electronics noisefloor of -80dB is all that would be required for optimal response. The only application where -80dB can be typically taken advantage of by a person is with headphones, which isolate some external noise. It is strongly suggested that [1]-75dB average noisefloor in electronics is appropriate for optimal response with loudspeakers, and [1]-80dB is appropriate for optimal response with headphones, as concluded by research and perceptual testing.

Now, additional SNR is good to have, simply from a persepective of having a wider tolerance for error(gain mismatches of equipment, etc.) and still achieving a sufficient SNR.

Another thing to think about is the electronics, you can have the same DAC and have a different sound quality. Theta Digital uses BurrBrown and so does NAD, and no one would ever confuse the two of sounding the same.

I have not seen a full set of measurements comparing the two, but if they do sound different, it would be revealed in proper measurements. The most likey difference(if one exists) will be frequency response difference.

-Chris

Footnotes
[1]
Signal-to-Noise Ratio Requirement for Digital Transmission Systems
Spikofski, Gerhard
AES Preprint: 2196

 

[Buckle-meister]

I have not seen a full set of measurements comparing the two, but if they do sound different, it would be revealed in proper measurements. The most likey difference(if one exists) will be frequency response difference.

Excuse my ignorance, but my understanding of frequency response is, for example, the human hearing range of 20Hz to 20kHz.

If this is true, then are you saying that the upper and lower frequency bounds might be different for DAC x compared to DAC y?

And if that is true, then wouldn't this simply imply a loss of information rather than a different 'feel' to the sound?

Regards

 

[WmAx]

Excuse my ignorance, but my understanding of frequency response is, for example, the human hearing range of 20Hz to 20kHz.

Frequency response, as is typically referred, is amplitude vs. frequency. The overall range would be referred to as the bandwidth. What I mean in my last response, is that the analog output stage(after the DAC) can be designed to filter the response slightly within an audible bandwidth, e.g.; -2dB at 10kHz, etc., relative the lower frequencies.

If this is true, then are you saying that the upper and lower frequency bounds might be different for DAC x compared to DAC y?

The final analog output will differ slightly between every DAC, due to the choice of different anti-alias filter topologies, but these differences are not shown to normally result in an audible difference. For example, DAC X may be -1dB by 19kHz while DAC Y may be -3dB by 20kHz. The anti-alias filter begins usually at frequencies greater than 18kHz, on a 44.1kHz PCM. Despite the example differences given above, this is not of audible consequence. It is outside of the sensative range of hearing. Another factor in real audible differences can be the failure to use a sufficient anti-alias filter, or even to go without an anti-alias filter at all. This will result in lower frequency artifacts in the signal, as a result of modulating the audio band information with the 44.1kHz sample frequency(which is filtered out in properly designed DACs). I know that some DACs do lack this critical filter, such as a couple of models from AudioNote.

And if that is true, then wouldn't this simply imply a loss of information rather than a different 'feel' to the sound?

Regards

The above discussed factors certainly can change the 'feel' of the sound, if of sufficient magnitude(s).

-Chris

 

[Buckle-meister]

Cheers WmAx

...Another factor in real audible differences can be the failure to use a sufficient anti-alias filter, or even to go without an anti-alias filter at all. This will result in lower frequency artifacts in the signal, as a result of modulating the audio band information with the 44.1kHz sample frequency(which is filtered out in properly designed DACs). I know that some DACs do lack this critical filter, such as a couple of models from AudioNote.

Doesn't that imply that the 'feel' of the sound from a given CD/DVD player is as a result of deficiencies rather than quality components?

 

[mtrycrafts]

I have to disagree I'm afraid.

One reason we are here and discussing


I am stunned by the picture and sound from my HT kit,

Great.


but let me be clear; I am a music lover first and foremost, so I certainly do not consider playback of CDs as nothing events.

Again, you are misunderstanding the state of audio technology and give weight to the hype passed on. Using the digital out from th eplayer will give you the best audio and purchasing a stand alone CD player cannot improve but can degrade if the design is euphonic by purpose.

Any way that I can squeeze more from a CD is of interest to me,

OK. Buy better Cds as not all recorded equally well, and work on your room acoustics, not CD players.

and whilst my questions may be trivial,

Not at all; that is why this board is here.

the answers I recieve to them may just prevent me from needlessly wasting my cash.

Regards

That is exactly why we are here, the separate out the audio voodoo, bs, etc.
So, CD playback today is not much of an issue as it is well understood and mostly executed well.

 

[mtrycrafts]

That last sentence; thats what I was talking about!!

Regards

So are we. Not rocket science to do CD players but some cater to the gullible audiophile community. Just because one may measure different doesn't mean you can hear the difference. Our hearing is rather limited.

 

[mtrycrafts]

Just a comparison a customer of mine took home the Yamaha DVDS-1500, he has a Sony DVD player cost around $99, was blown away by the audio and the video and he was using the digital out, if you are looking for a great little player and not wanting to spend the money on the DVDS-2500 which is now available. You won't be sorry you bought the 1500 at all.

I wonder if your custome really knows how to compare those two players without bias overwhelming his perceptions
I seriously doubt it, hence his perceptions are of dubious merit.

 

[Buckle-meister]

Again, you are misunderstanding the state of audio technology and give weight to the hype passed on. Using the digital out from th eplayer will give you the best audio and purchasing a stand alone CD player cannot improve but can degrade if the design is euphonic by purpose.

If the above is true, and I do not doubt you, then it is surely indicative of just how duped by hype I have been. In essence, you are saying that there is no difference in sound quality, using the digital out, between a budget and high-end CD player. Wow! I can scarcely believe it!

Yoda: You must unlearn...what you have learned.!!!

...and work on your room acoustics, not CD players.

You read my mind! I have a few more queries for you if you dont mind answering them?

After reading further Audioholics papers, I have been giving some thought to purchasing the Radio Shack (analogue) SPL meter in addition to AVIAs Guide to home theatre.

1. Is it recommended that I also purchase JKPs Digital video essentials for use with my DLP projector, or will AVIAs DVD do?

2. The following is a quote from the Audioholics paper Subwoofer Calibration Using Rives Audio Test CD 2: "Also, I had to increase the amount of delay to 20 feet even though the subwoofer is only 13 feet away." Doesn't this mean that the timing of the LFE information would be incorrect? Or does this not matter due to the non-directional nature of the sub coupled with the speed of sound and the 20-13=7 feet distance?

3. Armed with a tape measure, SPL meter, and my own limited knowledge, I have enough self-confidence (/over-confidence?!!) to manually set the wiring, distance, size and level parameters. However, this still leaves the Equalizing (composed of Frequency, level and Q-factor) which YPAO automatic calibration sets. Is it ill-advised to tamper with these? If not, where can I read-up on these subjects?

Finally, thanks for your replies. I am discovering that it can sometimes be quite tricky to post replies; most especially opinions, without conveying the feeling of 'stepping on someones toes'! It is not my intension to do so to anybody.

Thanks very much for your help.

Luke: ...but I've come so far [in such a short period of time]!!!.

Kind regards

Robbie

 

[mtrycrafts]

Well, it is great that you have further questions to me Not sure I can answer them all well enough but will try

If the above is true, and I do not doubt you, then it is surely indicative of just how duped by hype I have been.

Don't feel badly about this. Humans by nature are gullible, just look around to any consumer marketplace or beliefe systems.

In essence, you are saying that there is no difference in sound quality, using the digital out, between a budget and high-end CD player. Wow! I can scarcely believe it!

Yep, that is correct. How could the digital signal be altered to alter the analog signal conversion? The digital signal on a CD is grouped and scrambled, in easy to follow language (Reed Solomon cross interleaving, I believe it to be). To alter it, youy'd have to know which portions, where it is in the scrambled eggs to alter it intelligently, such as altering the high frequencies only.




You read my mind!

But I am not Sylvia Brown


After reading further Audioholics papers, I have been giving some thought to purchasing the Radio Shack (analogue) SPL meter in addition to AVIAs Guide to home theatre.

This is a small investment to add to your audio tool kit. The Avia has the video feature to adjust each color intensity, not sure if that Digital has it but, even adding that as a second test disc is a cheap investment and would recommend that too. Certainly cheaper than expensive wire of players and more productive results

1. Is it recommended that I also purchase JKPs Digital video essentials for use with my DLP projector, or will AVIAs DVD do?

As above, I would. Not that expensive. Look around for it. Amazon may have it available in used DVD, cheap. Make sure it has all the filters with it for the video tune up.


2. The following is a quote from the Audioholics paper Subwoofer Calibration Using Rives Audio Test CD 2: "Also, I had to increase the amount of delay to 20 feet even though the subwoofer is only 13 feet away." Doesn't this mean that the timing of the LFE information would be incorrect? Or does this not matter due to the non-directional nature of the sub coupled with the speed of sound and the 20-13=7 feet distance?

I read that too but not sure what to make of it. You may want to ask that in a new thread but tune yours to the classic setup, measure with tape and use that.

3. Armed with a tape measure, SPL meter, and my own limited knowledge, I have enough self-confidence (/over-confidence?!!) to manually set the wiring, distance, size and level parameters.

Go for it. All it can do is not sound quite right but it won'd harm any component.

However, this still leaves the Equalizing (composed of Frequency, level and Q-factor) which YPAO automatic calibration sets. Is it ill-advised to tamper with these? If not, where can I read-up on these subjects?

Try the auto setup and see what distances it comes up with. If it is close, leave it. If far off, I'd change to what you measures but the EQ will be set well enough. You can also ask this in a new thread.

Finally, thanks for your replies. I am discovering that it can sometimes be quite tricky to post replies; most especially opinions, without conveying the feeling of 'stepping on someones toes'!

Hey, don't feel like the Lone Ranger You will get the hang of it and stepping on toes are why we are here. Besides, no one will phisically strike back, I hope. Part of learning, asking and part of life.