[James Tanner]

James, I noticed above you quoted jitter figures for the BDP/BDA? How they measure jitter on the BDA? I understand  measuring the digital output of the BDP-1, but I don't follow why they include the BDA DAC? Do they pop the top off and measure at the some point along the digital stage?

Thanks

Hi - not sure on that - they just tell me the DAC is required to get meaningful numbers?

james

[Sasha]

My point does not have so much to do with T1's, as the jitter sensitivity of TDM circuits, and how we eliminate the jitter by using a buffering mechanism on the end nodes. I was originally asking why a DAC could not buffer ( I know some do), on the digital input side. This should effector eliminate any jitter introduced into the digital signal by the transport/pc etc.

Cheers,

Ok, understood now.
My experience was, confirmed countless number of times, that there is no such thing as complete jitter elimination, and all methods employed can only attenuate jitter but not eliminate it.
After all, we live in a world ruled by laws of physics.
 

[sfraser]

Hi - not sure on that - they just tell me the DAC is required to get meaningful numbers?

james

Maybe a passive monitor, that requires sync between the BDP and BDA?
......or perhaps the testers wanted to take the BDP/BDA home and listen to it over the weekend 

[Sasha]

Wow, what a thread    Where's Nap's insightful comments when we need it.

IMHO, comparing a CD Player and BDP with a 44.1/16 file is still a huge improvement even if you exclude the jitter discussion using a great dac (BDA) or a very poor dac (MF vDAC).  We can't ignore the fact that there are read errors with transports and cd rot or scratches on the disc so CDs might be a more reliable format than an LP, it's still not even remotely as reliable as a file.   Eventually when a reviewer reports the BDP-1's jitter playing a 44.1/16 file connected to the BDA or another dac then you will have the much needed numbers.   The reported jitter measurements with the BDP/BDA for the higher rez files are amazing, it would be interesting to know what products have less jitter at any file resolution.

For those stuck on playing back music with a computer, do yourself a favor and at least do a home audition of the BDP even if is for kicks.   If your only goal is to playback audio, the BDP will have the advantage over any computer with it's custom power supply, modified sound card and an OS that only runs the minimal service required not to mention no video card, no wifi, no bluetooth, etc.   Running Windows 7 or Mac OSX, you will still be running a few dozen processes that are unnecessary for playback, not to mention the various software and tricks you need to do to ensure correct playback.  In the end you will always be second guessing it after each OS or application update.   

As for the various file formats, there are very few products that can decode audio streams other than PCM or DSD on die.  Several of the newer generation Apple products can decode h.264 and by extension AAC and possibly Apple Lossless.  I'm not aware of any products that will decode FLAC or WMV on die.  For most DIY HW, Linux, Windows and even the BDP, the only audio stream accepted to the sound-card will be PCM, so the driver or perhaps the application will perform the task of converting it to PCM before shipping it off to the sound card.   

The fun thing about the BDP is that you can monitor the CPU utilization with various file formats and clearly AIFF and WAV 44.1/16 is the lowest, next is ALAC 44.1/16, followed by 44.1/16 FLAC, and then 96/24 WAV and 96/24 FLAC following the rear (just random songs, monitoring the load and cpu utilization).  I've downloaded one album (free) in 96/24 FLAC, 96/24 WAV and 44.1/16 ALAC, and went ahead using the WAV file to create 44.1/16 FLAC and 96/24 ALAC, and added them all to the playlist.  It's very difficult to hear a difference between the various formats, but I do feel that I can pick out the 96/24 over 44.1/16.

I have to make comments on many of the statements here because they create distorted picture.

First, no one is disputing that error correction in CD player does not work well with damaged disks, however that is not the point. You have to create an even playing field if you want to make proper comparison. Do not assume you are dealing with scratched and rotten CDs. Otherwise the same assumption can be made for bad memory used in whatever form on PC based transport.
So you begin with good CD where error correction does not have to take place.

Second, quoted numbers are meaningless till they cover 16/44.1, again I am talking about CD playback.

Third, quoted numbers are meaningless till individual components are measured (not combination BDP-1/BDA-1), and it is clearly explained where and how measurements took place.
Otherwise there is no any kind of comparison, you are either stating the measurements of an entire system, or preference for an entire system.
Again, take top end CD player with digital I/O and start making measurements and subjective comparison. Till this is done, all the numbers quoted from BDP-1/BDA-1 are meaningless and have no bearing whatsoever on the subject and my contention.
Same goes for any subjective assessment of a standalone CD player versa  BDP-1/BDA-1, that is absolutely meaningless in this context, you are comparing combinations of many different components together in a system, and whoever says that BDP-1/BDA-1 is better than X, it only means that they prefer the sound of BDP-1/BDA-1 but they cannot say if it is because of different conversion (because it is different from a standalone CD player), or analog section (because it is again different), or different upsampler, or better match of output impedance in their system (because it is again different), or indeed because BDP-1 is better transport.
Skewed logic cannot be used as an argument.

Fourth, the statement that “BDP will have the advantage over any computer” is a gross generalization. There are PC based transports that have been built with the same care in minimizing power noise, OS footprint, etc, the way it is done in BDP-1.
And if those PC based transports use better quality components there is absolutely no base for such statement, in fact the opposite could be argued.

Fifth, the difference between different formats on a resolute system, especially with such significant jump such as 96/24 over 44.1/16, is clearly audible, so how can the inability to hear it or barely being able to hear it be used as an argument for supremacy of BDP-1?

[sfraser]

Ok, understood now.
My experience was, confirmed countless number of times, that there is no such thing as complete jitter elimination, and all methods employed can only attenuate jitter but not eliminate it.
After all, we live in a world ruled by laws of physics.

Ok, I agree with the laws of physics . But in mind mind (and I could be missing important attributes) in regards to jitter the focus should be on the DAC, not the transport. For instance if the input buffer stage of a said DAC is designed to buffer and re-clock the incoming digital signal, the jitter introduced by the transport should be effectively eliminated. However, having said that, it si quite possible that  new jitter could be reintroduced within the DAC as the digital signal is played out to the next stage of the DAC circuitry.

James, could you run this by your engineers? I have the feeling the fly in the ointment maybe in the re-clocking.

Thanks,

Great fun! now back to my day job.

[Sasha]

Ok, I agree with the laws of physics . But in mind mind (and I could be missing important attributes) in regards to jitter the focus should be on the DAC, not the transport. For instance if the input buffer stage of a said DAC is designed to buffer and re-clock the incoming digital signal, the jitter introduced by the transport should be effectively eliminated. However, having said that, it si quite possible that  new jitter could be reintroduced within the DAC as the digital signal is played out to the next stage of the DAC circuitry.

James, could you run this by your engineers? I have the feeling the fly in the ointment maybe in the re-clocking.

Thanks,

Great fun! now back to my day job.

I understand what you are saying, but make a simple experiment, take a number of different digital sources all producing different amounts of jitter, connect them to any DAC, including BDA-1, using different inputs.
If the theory that buffering and re-clocking should effectively eliminate jitter is not baseless, then all those sources over all those different interfaces should sound the same, logic would dictate that, correct?
Why would you then even spend money on BDP-1 if you can get the same result with some $200.00 digital source?
Well, you are in for a big surprise, they all sound different.
So if all of them send bit perfect signal, and jitter is eliminated, explain why they sound different?

[sfraser]

I understand what you are saying, but make a simple experiment, take a number of different digital sources all producing different amounts of jitter, connect them to any DAC, including BDA-1, using different inputs.
If the theory that buffering and re-clocking should effectively eliminate jitter is not baseless, then all those sources over all those different interfaces should sound the same, logic would dictate that, correct?
Why would you then even spend money on BDP-1 if you can get the same result with some $200.00 digital source?
Well, you are in for a big surprise, they all sound different.
So if all of them send bit perfect signal, and jitter is eliminated, explain why they sound different?

Well to be honest, I have never heard a difference between transports playing the same source file into the same DAC.

[James Tanner]

James, what size of input buffer does the Bryston DAC have?

Thanks

Hi,

Engineering tells me it is part of the upsampler chip and TI does not give us that information.

james

[Sasha]

Well to be honest, I have never heard a difference between transports playing the same source file into the same DAC.

Ok, fair enough, I do hear the difference, sometimes significant one.
This is why there is so much contention on the subject, some simply cannot hear what others can, for whatever reason.

[werd]

Ok, fair enough, I do hear the difference, sometimes significant one.
This is why there is so much contention on the subject, some simply cannot hear what others can, for whatever reason.

Everything you do in-front of the dac will get amplified. This can be jitter or noise related issues.

[skunark]

I have to make comments on many of the statements here because they create distorted picture.

And the fact that you are unwilling to demo isn't?  You seem to be very passionate about your opinions, so today at least I'm not going to fire back, but just ask you to do the demo and get a few hours under your belt with the BDP.   If you still feel the same, then fine, i will respect that.   i do feel that measurements should be treated as guidelines but it doesn't mean an amp with 0.007% distortion will sound better than one with a 0.1% distortion, there's several factors besides distortion and jitter that makes a system click.  Even the weight of the component can indicate it's higher quality, but has no influence on the sound. 

Also, Feel free to list what computer build would be equivalent to the BDP, and do list out the OS and the software.  I would be interested to know what you would build.  If you are okay with using the BDA as the DAC, please spec it out with an AES EBU and keep it below $2,150.  If you want the DAC build in, then i guess you can spend $4,250, but make sure it has balanced outputs.   

And as for the file format wars,  this is all rather funny to me as all sound cards have to accept PCM data streams, and folks swear that one is better than the other. Sure if there is a bug in the software that converts from FLAC to PCM, then yeah it's a problem, and maybe WAV and AIFF are the safer bet to minimize the amount of time the software handles the data, but a bug free set up, there's no difference.  As for High Rez vs Red Book, most systems won't be able to hear the difference as they just don't have the resolution. 

I was rather honest stating that in my system I can barely hear a difference between high-rez and redbook, but i did hear a difference.    Since I've almost entirely have played 44.1/16 based music over the years, saying that the BDP is the best source I've owned or demoed is also an honest statement, and I'm not the only one.

[skunark]

Hi,

Engineering tells me it is part of the upsampler chip and TI does not give us that information.

james

Part number of the TI chip? 

[Sasha]

And the fact that you are unwilling to demo isn't?  You seem to be very passionate about your opinions, so today at least I'm not going to fire back, but just ask you to do the demo and get a few hours under your belt with the BDP.   If you still feel the same, then fine, i will respect that.   i do feel that measurements should be treated as guidelines but it doesn't mean an amp with 0.007% distortion will sound better than one with a 0.1% distortion, there's several factors besides distortion and jitter that makes a system click.  Even the weight of the component can indicate it's higher quality, but has no influence on the sound. 

Also, Feel free to list what computer build would be equivalent to the BDP, and do list out the OS and the software.  I would be interested to know what you would build.  If you are okay with using the BDA as the DAC, please spec it out with an AES EBU and keep it below $2,150.  If you want the DAC build in, then i guess you can spend $4,250, but make sure it has balanced outputs.   

And as for the file format wars,  this is all rather funny to me as all sound cards have to accept PCM data streams, and folks swear that one is better than the other. Sure if there is a bug in the software that converts from FLAC to PCM, then yeah it's a problem, and maybe WAV and AIFF are the safer bet to minimize the amount of time the software handles the data, but a bug free set up, there's no difference.  As for High Rez vs Red Book, most systems won't be able to hear the difference as they just don't have the resolution. 

I was rather honest stating that in my system I can barely hear a difference between high-rez and redbook, but i did hear a difference.    Since I've almost entirely have played 44.1/16 based music over the years, saying that the BDP is the source I've owned or demoed is also an honest statement, and I'm not the only one.

Thanks for well balanced answer 

[sfraser]

Part number of the TI chip?

I am guessing TI = Texas Instruments.

[James Tanner]

I am guessing TI = Texas Instruments.

Yes

[sfraser]

Everything you do in-front of the dac will get amplified. This can be jitter or noise related issues.

The point I was making, is that by buffering  at the DAC input, any transport jitter should be reduced to non substantial numbers. Yes the DAC could potential introduce it's own jitter as it plays out the data stream to the next stage. In regards to noise are you referring to the analog stage or digital?

[ricko01]

So unless I am interpreting things incorrectly it seems like the BDP/BDA  has lower jitter numbers than even the best of the CD Players?

james

No disrespect to James or anyone else.... but at some point its all diminishing returns.

Jitter is important but at a certain point it becomes academic. Other parts of the "food chain" swamp the lack of distortion presented by low jitter numbers.

If you use a CD player/transport as a transport for example, then it forces the DAC and the transport/DAC interface to bear the brunt of carrying the transport jitter (or lack there of) forward.

In the case of an "integrated" CD player, then the jitter is what it is intrinsically, but the analogue section needs to bear the brunt of carrying the CD jitter (or lack  there of) forward.

So what I am saying is that a pure technical number is just that, an isolated metric that needs to be considered as part of a complete chain to have meaning.

A device with 1ps, while essentially perfect, doesnt matter when referenced against the downstream distortions a systems components has.

Peter

[werd]

The point I was making, is that by buffering  at the DAC input, any transport jitter should be reduced to non substantial numbers. Yes the DAC could potential introduce it's own jitter as it plays out the data stream to the next stage. In regards to noise are you referring to the analog stage or digital?

I think the  jitter that has an effect is jitter off the clock in the bdp (the one on card). I would say its best measured at a point right before the dac in the bda.

I also think that jitter in pico time length is the big joke of the 21 cent in audio. I doubt very much jitter is being measured at that time length in audio.

What you are talking about Sfraser sounds more like fanning out then jitter. Fanning out insures that previous logic can drive all the forward logic successfully and sink all the current back until its converted to AC.