JPLAY Responds: An Open Letter

[jkeny]

Perhaps I should just post blanks to threads like this.

Tim

I perceive that is what you are doing, indeed!

 

[Phelonious Ponk]

I perceive that is what you are doing, indeed!

Good one, John. They really should be easier for you to refute, then.

Tim

 

[microstrip]

...I rest my case. Oh and make this "all of these tests that challenged their core beliefs were flawed." They usually fail to find fault with the tests that agree with them.

Oh, and this description of an exhaustive process?



I didn't make it up. Any guesses as to what study I'm talking about? Hint: it was broadly and immediately rejected by the high-end community. And bear in mind, that's a description of what I believe it would take to possibly change a few audiophile minds, not what it would take to make a statistically valid test. That's a lot easier.

Tim

Tim,
Please give us facts - nominate and refer explicit to the tests you are addressing. Although I think that the ALL you refer are the usual very few, may be you are referring to something more recent.

 

[Phelonious Ponk]

A very good point. And I want to add a comparison from my profession of professional violin playing: In the business of providing violins ("master" violins) to the aspiring young fiddler, violin dealers nowadays rarely let you take out an instrument, partly because the high value is difficult to insure for a few days (or so they say), and partly to keep control over the evaluating process:
There has been a lot of Stradivarius bashing of late, which will not confuse any true specialist: A Strad is a fantastic stile of instrument, among many other fabulous makers of comparable quality, be it old or new
But to get to know it, and being able to handle it, you usually need an extremely light hand and a free mind, which is unlikely in a "TEST" situation.

Why am I writing this: You will never hear what it (be it a violin or an audio system..) can do within a split second. I am a firm believer of extended assessments, where the results hit you, just like Tim says, without any proof ;-)
egidius

I'm a firm believer in extended assessments of systems as well. It takes us a while to decide what we like. Where quick switching is valuable is in verifying perceived small differences, or in determining whether or not perceived large differences are, in fact, small. Many, for example, think the difference between a good 256 or 320 VBR and uncompressed audio is glaringly obvious. Few can differentiate them blind, in quick switching, at a rate that supports "glaringly obvious." Other examples are even more dramatic. Some widely-accepted benefits, thought to be obvious, have been just plain inaudible when knowledge of what was playing was taken away. Audiophiles have not only denied the results, they have continued to believe, and profess that the differences, undetectable unsighted, are obvious to anyone with good hearing and a good system. Myths die hard.

Tim

 

[Phelonious Ponk]

Tim,
Please give us facts - nominate and refer explicit to the tests you are addressing. Although I think that the ALL you refer are the usual very few, may be you are referring to something more recent.

Nah. They've all been argued out on internet audiophile boards to exhaustion. I see no good reason to re-live them here. It would change no one's mind.

Tim

 

[microstrip]

Nah. They've all been argued out on internet audiophile boards to exhaustion. I see no good reason to re-live them here. It would change no one's mind.

Tim

OK. I understand that you were just addressing the old exhausted flags. Surely they will not change any one mind.

 

[Phelonious Ponk]

OK. I understand that you were just addressing the old exhausted flags. Surely they will not change any one mind.

I don't think the flags have been exhausted, I think they have just been ignored and denied, but no, flying theme again is not likely, to change anyone's mind; it'll just resurrect old arguments.

Tim

 

[NorthStar]

Perhaps I should just post blanks to threads like this.

Tim

I got a bunch of those here, in several threads.

* Sorry Tim, I just couldn't resist.

 

[jkeny]

So after all this talk, has anybody newly downloaded Jplay & tried it? Do you wish to report your listening impressions & configuration?

 

[joelha]

jkeny,

I'm not sure how long someone has to have been using JPLAY to be a new user, but my JPLAY experience really began with 5.1.

In short, I won't listen to digital without it. And realize I tried JPLAY version 4 and didn't think much of it. So when I tried 5.1 my inclination was not to like it.

Between the remarkable focus it's brought to my music and the many ways in which the program can be customized (both through software settings and hardware configurations) the improvements are as great as any hobbyist is willing to make them. But even if you want to install the software and listen with minimal tweaking, the improvements are remarkable.

My configuration is Streamer Mode (each PC connected by lan cable), Ultra Stream #30 for redbook and above, and #100 for DSD files.

Using Core Server with Audiophil's script on my Audiopc.

For anyone who isn't sure about JPLAY, the trial is free and fully featured.

If you don't like it, uninstall it but if you do like it, you're likely to enjoy it a lot.

Joel

P.S. I have zero financial interest in JPLAY.

 

[jkeny]

Yep, Joel but I just wondered how many might have tried it since there was a lot of theoretical opinion on this thread but little experiential information. Seeing as it's a 5 minute download & install, I wondered how many had even tried it.

 

[Elberoth]

I've been wondering, what people who are so hard on Jplay think about differencies in sound quality between Mac and PC platforms ?

Almost everyone that tried both agrees, that PC sounds better than Mac (including the founder of Computer Audiophile, who said that openly many times), and yet, the measurements published on that site, made by the same person that tried to measure Jplay effect, show zero difference between the two.

Are there really no differencies, or maybe the resolution of measuring equipment used is just not good enough ? Or maybe we are measuring the wrong things altogether ?

I still remember the discovery of jitter pheomenon. In the 80s audio designers have lived in a total bliss, untill someone discovered and learned how to measure a new type of distortions.

Just a thought.

 

[Julf]

I've been wondering, what people who are so hard on Jplay think about differencies in sound quality between Mac and PC platforms?

Are we talking about "PC platforms" in terms of hardware (so including PCs running Linux and other non-MS operating systems)? What hardware generations are we talking about? Or are we talking about Windows vs. OSX (possibly on same hardware)? Which versions of Windows?

Almost everyone that tried both agrees, that PC sounds better than Mac

A lot of people I have talked to disagree, but that could be because the image of the Mac environment as more "media-friendly".

Are there really no differencies, or maybe the resolution of measuring equipment used is just not good enough? Or maybe we are measuring the wrong things altogether?

I think the first step, before asking about the measurements, is reliably establishing that there really are differences.

 

[barrows]

A couple of points: first, I have not tried jplay, as I do not use windozs. I use a custom linux server, which is already optimized for music playback alone.
The reason that folks are skeptical about the supposed sound quality advantages of jplay is that even the developer themselves cannot even offer a single plausible reason for any improvement in the case of a well designed, asynchronous USB DAC. Perhaps jplay are just being coy, and would rather not divulge proprietary secrets, but the absurd elements of its operation which they have mentioned here is not doing them any favors: in fact, I think they could be more convincing by just claiming they use a proprietary approach.
In my experience, electrical and airborne noise from a computer music server can, and often does, affect an audio system negatively, when the serving device is located in close proximity to the system, and/or powered from the same mains supply. It is in this area where, I believe, some music player SW programs can have an advantage (and purpose built servers as well); by shutting down all operations on the server not needed for audio playback, noise levels drop, and sound quality can improve, in some systems. Windows, of course, is notorious for the amount of computer resources it uses just to be running-so if jplay minimizes CPU load, and hence power consumption and noise levels, I could accept that having a positive effect in some systems. Of course, there are probably other ways to accomplish the same thing.
I am a little bewildered by jkenny's apparent lack of knowledge on how to properly isolate a USB interface though? I thought he was much more knowledgable about this? The approach which does work, is as follows: lets consider a system using the XMOS processor for our example, USB cable comes from server, and goes to the USB receive board (inside DAC). The XMOS processor is powered form the USB bus, and grounded to the host server, this is the "dirty" side of the system. Then the I2S output of the XMOS goes through isolation chips (typically GMRs), these isolate everything including ground. On the "clean" side of the interface we have the oscillators, and a signal processing chip. The "clean" side is powered from a clean power supply of its own, and the masterclock clock is sent back to the XMOS through the isolation. The I2S signal is re-clocked by the oscillators on the clean side, removing any jitter from the XMOS output and the added jitter from the GMR isolators. This approach allows for jitter at the intrinsic level of the oscillators, and has no limitation on sample rate. This is the approach used by the best USB interfaces, both internal to DACs, and as external USB-SPDIF converters.

 

[jkeny]

A couple of points: first, I have not tried jplay, as I do not use windozs. I use a custom linux server, which is already optimized for music playback alone.
The reason that folks are skeptical about the supposed sound quality advantages of jplay is that even the developer themselves cannot even offer a single plausible reason for any improvement in the case of a well designed, asynchronous USB DAC. Perhaps jplay are just being coy, and would rather not divulge proprietary secrets, but the absurd elements of its operation which they have mentioned here is not doing them any favors: in fact, I think they could be more convincing by just claiming they use a proprietary approach.
In my experience, electrical and airborne noise from a computer music server can, and often does, affect an audio system negatively, when the serving device is located in close proximity to the system, and/or powered from the same mains supply. It is in this area where, I believe, some music player SW programs can have an advantage (and purpose built servers as well); by shutting down all operations on the server not needed for audio playback, noise levels drop, and sound quality can improve, in some systems. Windows, of course, is notorious for the amount of computer resources it uses just to be running-so if jplay minimizes CPU load, and hence power consumption and noise levels, I could accept that having a positive effect in some systems. Of course, there are probably other ways to accomplish the same thing.

I am a little bewildered by jkenny's apparent lack of knowledge on how to properly isolate a USB interface though? I thought he was much more knowledgable about this? The approach which does work, is as follows: lets consider a system using the XMOS processor for our example, USB cable comes from server, and goes to the USB receive board (inside DAC). The XMOS processor is powered form the USB bus, and grounded to the host server, this is the "dirty" side of the system. Then the I2S output of the XMOS goes through isolation chips (typically GMRs), these isolate everything including ground. On the "clean" side of the interface we have the oscillators, and a signal processing chip. The "clean" side is powered from a clean power supply of its own, and the masterclock clock is sent back to the XMOS through the isolation. The I2S signal is re-clocked by the oscillators on the clean side, removing any jitter from the XMOS output and the added jitter from the GMR isolators. This approach allows for jitter at the intrinsic level of the oscillators, and has no limitation on sample rate. This is the approach used by the best USB interfaces, both internal to DACs, and as external USB-SPDIF converters.

I see you said "apparent lack of knowledge". I already built this configuration.

I'm really interested in the fact that nobody on this thread has tried to download & try Jplay

 

[barrows]

John: OK, so why then did you claim earlier in this thread that applying appropriate isolation to a USB receiver is difficult? I am still confused? Clearly, there is an appropriate solution, which is in common use in the better USB interfaces.

 

[jkeny]

John: OK, so why then did you claim earlier in this thread that applying appropriate isolation to a USB receiver is difficult? I am still confused? Clearly, there is an appropriate solution, which is in common use in the better USB interfaces.

First off you are not fully isolating the USB receiver, are you - the USB receiver is still in contact with the PC ground & in your XMOS case driven by the noisy VBus - you really think this isolates it? I used a USB receiver that was not powered from Vbus.

Second, care to tell me how many USB converters or DACs are configured such?

Thirdly, do you know this solves the issue or are you working on theory as you are with Jplay i.e have you tried this type of USB converter/DAC?

 

[barrows]

First off you are not fully isolating the USB receiver, are you - the USB receiver is still in contact with the PC ground & in your XMOS case driven by the noisy VBus - you really think this isolates it? I used a USB receiver that was not powered from Vbus.

Second, care to tell me how many USB converters or DACs are configured such?

Thirdly, do you know this solves the issue or are you working on theory as you are with Jplay i.e have you tried this type of USB converter/DAC?

1. It matters not. The noise stays on the XMOS side, and the signal is re-clocked on the output side directly by the oscillator(s). There is no ground connection between the computer/XMOS side and the output/clock/DAC side, nor any sharing of noise. Of course, one could also provide a clean supply (separate transformer or battery) if one was paranoid about it. I prefer to use an separately powered USB card on the server side, to insure clean power supply to the XMOS side.
2. Do not know, but here are a few: Ayre DACs, Wavelength Audio DACs, MSB operates with their own variation on this same theme, Berkeley Alpha USB-SPDIF, Audiobyte Hydra USB-SPDI-I2S. I suspect there are more, but those are the ones I know off of the top of my head. There are also various DIY solutions for this, as you likely well know.
3. Solves what "issue" exactly? I do not think we are dealing here with any well established issues. The only issue which I accept in this environment, is that nosie from the server may couple into the sensitive oscillators, DAC, and analog output stage. This method of isolation does solve the problem of cable borne noise, airborne RF needs to addressed separately if it is a problem.

 

[jkeny]

1. It matters not. The noise stays on the XMOS side, and the signal is re-clocked on the output side directly by the oscillator(s). There is no ground connection between the computer/XMOS side and the output/clock/DAC side, nor any sharing of noise. Of course, one could also provide a clean supply (separate transformer or battery) if one was paranoid about it. I prefer to use an separately powered USB card on the server side, to insure clean power supply to the XMOS side.
2. Do not know, but here are a few: Ayre DACs, Wavelength Audio DACs, MSB operates with their own variation on this same theme, Berkeley Alpha USB-SPDIF, Audiobyte Hydra USB-SPDI-I2S. I suspect there are more, but those are the ones I know off of the top of my head. There are also various DIY solutions for this, as you likely well know.

So if a €100 Jplay software does as good as these expensive devices with regard to noise isolation, are you complaining?

3. Solves what "issue" exactly? I do not think we are dealing here with any well established issues. The only issue which I accept in this environment, is that nosie from the server may couple into the sensitive oscillators, DAC, and analog output stage. This method of isolation does solve the problem of cable borne noise, airborne RF needs to addressed separately if it is a problem.

Yes, the noise "issue" was the one you raised & I was speaking of. So, as I asked have you tried one of these DAcs that you have listed? What is your experience with it's isolation characteristics?

 

[amirm]

So if a €100 Jplay software does as good as these expensive devices with regard to noise isolation, are you complaining?

Where is any measurement to show similar noise reduction and isolation? From the descriptions provided, Jplay is actually increasing CPU load by using short buffers. So even the theory doesn't support what you say.