Matrix X-SPDIF 2

…or that it won’t one day be measurable:)

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I haven’t been reading this thread assiduously, but just in case the point hasn’t been made phase noise is basically lower frequency jitter. It’s also the main part of jitter that matters to audio. Attacking phase noise anywhere where people attack jitter will be more effective than worrying about all jitter. The lower the frequency of jitter the harder it is to measure. It costs a heck of a lot to get accurate measurements of phase noise - FWIW Neither I nor PS Audio can afford the equipment to measure the phase noise that I’d like to measure on the DS.

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@tedsmith,

Could you afford to rent the equipment? John Swenson was supposed to be designing and building his own equipment to measure this clock phase noise. But, he could certainly rent the equipment if he could not build it and perform the tests to show how well the EtherREGEN performed.

I always assumed this noise existed but did not and do not understand how it would be propagated over Ethernet. You saying it does exist and is difficult to measure makes me feel better about the concept of the EtherREGEN. But, I would still like to measurements that show the noise and then show the noise after passing through the EtherREGEN.

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Sound reasoning, but if the means to measure the EtherRegen are cost prohibitive and will not be done, you could be missing out an a device that brings significant improvement to your system. If I am not mistaken, doesn’t Uptone offer a money back guarantee? Then you can use your ears as you did with the ultraRendu without succumbing to financial risk. If it sucks, send it back. The only risk is being temporarily deprived of the purchase price after testing and returning the device. Seems worth it to me.

Yes, 30 days.

As with all things, observations comes first. Then we try to explain the observation. If the units make a system sound better the question becomes, why?

In so far as jitter matters over Ethernet in an audio system, phase noise matters more. Noise anywhere in a system can modulate the levels of the power or ground or reference for a rising or falling clock. These all affect jitter. Conversely jitter anywhere in a system will affect the timing of clock edges and hence the spectrum of noise on the power rails. Overall, any jitter or noise in a system can be propagated thru any path that passes jitter or noise. Most of the time the jitter/noise at the source is greatly attenuated before it gets to the DAC and the jitter/noise at the DAC matters the most. Still the best anything that filters jitter can do is to low pass filter that jitter - but what’s left (phase noise) is what matters most to audio. Things like buffers in USB or Ethernet may attenuate jitter above the PLL control loop bandwidth, but the phase noise below that isn’t attenuated.
Paying attention to phase noise in a system is important, but less important the further away from the DAC you are.

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Perhaps this will help.

Lets assume the phase noise at the source is very simply a variance at 1Hz. All of the buffering in the system, the clocks in the Ethernet, etc. will be tracking that 1Hz variance so their buffers don’t get too full or too empty. That 1Hz variance will show up at the destination (tho probably not at the same level.)

1Hz may not matter much, but lower frequencies are usually called “wow” and we know that that matters, somewhat higher frequencies, say 10Hz are audible since it modifies the output frequencies of the DAC by 10Hz (tho at a low level.) That compromises the bass performance somewhat…

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For more details on the results of phase noise see
https://www.analog.com/en/analog-dialogue/articles/analyzing-and-managing-the-impact-of-supply-noise-and-clock-jitter-on-high-speed-dac-phase-noise.html
and in particular figure 4 which shows the phase noise spectrum affecting EVERY frequency being reproduced by the DAC.

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Interesting information. So the EtherREGEN, if it indeed filters out clock phase noise, could have a noticeable impact on what comes out of the DAC and what we hear out of our speakers.

How noticeable do you think this could be? $640 noticeable??

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I have no opinion on the audibility of the EtherREGEN since I haven’t heard one. I’m just pointing out that phase noise does matter and it’s worth trying to minimize it. John’s a good egg and I’m sure he’s doing something worth doing. I don’t know how much difference it makes in any given system. I have heard the USB REGEN. It’s design makes sense and it made a noticeable difference to my ears, but once again I don’t know different it might sound in any given system, nor the value for any given person.

I should also add that I take a lot of pains in the DS to filter jitter and phase noise. I don’t know if the EtherREGEN has a lower control loop bandwidth than the DS.

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With the DirectStream DAC?

Yes. They brought it to the PS Audio room at a show and Paul asked them to leave it in the system…

I appreciate all of your extremely transparent and honest feedback. But this is at the crux of what I don’t understand. If you put forth great effort to reduce phase noise, how can you possibly know if you are successful if it’s not measured?

I also don’t understand why it can’t be measured. I cannot afford a MRI machine. They cost millions. Yet I’m able to pay a few thousand dollars and have a MRI performed. Can’t PS Audio scrape up the cash to have phase noise tested by someone who does own such a machine?

Do such machines exist at all?

Continuing the medical parallel with the EtherRegen. Isn’t it akin to saying we cannot prove this disease exists. We cannot prove that you have this disease. We cannot prove our protocol treats this disease. Please sign here, here, and here :hugs:

Back to the EtherRegen. I have no doubt that adding 2 cables, a LPS, and a cheap black box will alter the sound. It may do so in a positive way. It’s very difficult to accept, based on scientific confirmation, that the alteration has anything to do with the jargon on the Uptone website.

It definitely passes the smell test, so IMO it’s worth trying if you want. If you aren’t interested, don’t. It’s no different than power cords, interconnects etc. which usually have less “proof” in their marketing. If you believe in and like tweaking, it’s something to consider. Just because you don’t understand all of the principles used in the design of your audio equipment doesn’t mean you can’t enjoy it.

If I took the time to “prove” every piece of knowledge I used in designing the DS, I’d still be at it and have much less money to buy equipment. I’ll make more customers happy by working on new software and new hardware. If people don’t believe I know what I’m doing or that I grossly misallocate the budget when designing a DAC it’s no skin off of my nose. I can only do what I think is right. I want to make customers happy. And, for what it’s worth, my experience is that skeptics don’t believe measurements of things they don’t believe in, just ask Galen about his measurements of his ICONOCLAST cables.

[P.S. I’m not trying to sound testy (no pun intended) I don’t try tweaks I don’t understand or believe in. But if I hear a difference in someone’s system from such a tweak I’ll revisit it.]

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I’m on the same track as you, preferring ease of listening, etc vs resolution. In your thoughtful and thorough journey, what products have you found that further your goals?

Thanks

Well said!

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I understand. But, if you were selling a device which sole purpose was to reduce clock phase noise, wouldn’t you want to show that it did indeed reduce clock phase noise?

Word!

Yes, but much more important is how it interacts with various systems and how people like the difference it makes in audio quality. But if people don’t understand exactly what’s being measured and how the changes in measurements affect the sound they won’t believe them anyway. Very few demand proof that jitter reduction devices reduce jitter. And some of the jitter measurements that I’ve seen by “neutral” third parties don’t have any real idea what really matters in the measurements.
I guess what I’m saying is that I don’t know why phase noise reduction is being treated with more scrutiny than many other tweaks. The theory is sounder than most products that claim sound quality improvements, e.g. from reducing jitter.

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@dancingsea, this admission is a little embarrassing because I just recently bought new stereo components after using my old system for nearly 40 years. In a sense, I am a newbee of 2 years. I am not selling for a particular brand but I was lucky to like the first components that I auditioned and as you would expect I was super impressed at what modern electronics have to offer.
Now I decided not to continued with vinyl or reel to reel even head phones because component costs got out of hand real fast. I love CDs.

Well when I decided to sit in my chair (my dog won’t change the CD for me), I looked to streaming. I tried Sonore UltraRendu with a SonicOrbiter server to get off the laptop and rip my CDs in flac. I purposely have omitted identifying power supplies and cables to keep this response short.

Now, I was heavily influenced by this Matrix X topic, the first 1,000 replies covered a lot of information. A couple of the guys offered, suggestions and here is where my little embarrassment comes in, I was extremely pleased with my first streamer/server trialed; so I kept all. I have read where others have experienced disappointments. But I have concluded from this blog that there are many good setups, but they need to work with your system (synergy which is vip). Testing should get you results. Try to get a 100 to 250 hours of listening (combined critical and casual) is my rule of thumb, up to 250 for major components.

Outside of the PS Audio blog, I like John Darko with a little Steve Guttenberg. I find their reviews easy and informative to follow.

Have fun and good Listening.

Chas