[jtwrace]

This is a very interesting product From Alex @ UpTone (Designed by John Swenson):

Well Jason at Schiit does not like to make claims (I admire that among many other excellent business practices of theirs), but in his long blog/book on HeadFi he does talk about the SQ differences the Wyrd can make.  But as John pointed out, the degree depends upon both the computer and the DAC.  But the design of both the Wyrd and our Regen is absolutely not just about providing cleaner 5V USBVbus power.  One does not need a hub chip, clocks, etc. to do that.  In fact, in designing the piece, John and I discussed whether to even interrupt the USB VBus power to provide our own, but of course it made sense to do so.


So yes, both the Wyrd and the Regen will perform their primary purpose even if the DAC does not use 5V Vbus power at all.  (John did some trick things to make ours work/sound extra good: 4 layer board with impedance-controlled output, ultra low-noise regulators, external DC supply--Wyrd brings low voltage AC into it, no USB output cable--I'll be proving USB A>B solid adapter so tiny box can go at the DAC and not introduce another USB cable.)


As for the advantages, it comes back to the research he has been doing on packet noise (where poor SI makes the DAC's USB PHY and processor work harder--causing internal modulation at both 8KHz packet rate and wideband), power distribution networks, etc.  So Regn places creation of new and clean USB signal right at the DAC.  Kind of like an external version of an audiophile USB card (SOtM, Paul Pang, etc.), but at the correct end of the cable and not powered by the computer.  A boon for Mac users for whom such cards don't even exist.


I'd like to refer you to some of John's directly related recent writing: http://www.computeraudiophile.com/f10-music-servers/mac-mini-version-computer-audiophile-pocket-server-music-server-step-step-17666/index10.html#post370186


Would like to be in production within the next 12 weeks or so.  No price set as I have not gotten quotes for milling of the tiny (55mm x 45mm) enclosure's end caps or the PCB fab/stuffing.  Here is a pic of the not final version of the board (final is rearranged and has a big capacitor on it).


 


P.S.  I just realized that this thread is titled "Ethernet to DAC Connection," so this USB hub talk is completely OT.  Sorry.
Ethernet to DAC is a bigger project we have also been working on for a long time, but I really need to be careful not to use the forum for promotion.  The above already treads that line a bit.  Besides, you can find my fairly detailed hinting about out USB>Ethernet Audio Bridge project elsewhere.  It is no longer a secret.

From John Swenson:

Due to the large number of questions I'm not going to quote each one here, I hope I cover them all.


The isolation between computer and DAC was not a primary focus of what I am talking about now. Test I did seem to show this is not as big an issue as many previously supposed.


This post is primarily about the impact of the PDN on the generation of PS noise at sensitive chips in a DAC (main oscillator, DAC chip). In particular how a packetized data delivery (USB, Ethernet) significantly exacerbates this. Primarily because the packetized system produces current through the PDN with a much greater bandwidth than non-packetized systems (say I2S). Producing PDN to work well over this wide bandwidth is MUCH harder than for a non-packetized system.


On the question of WiFi: it is also a packetized system, and because of all the processing going on in WiFi, probably much worse than straight wired Ethernet.


On isolation, I have been including full isolation between digital sections and mixed signal sections for many many years. I do not use optical isolators, I do not like them at all, I prefer the GMR (Giant Magneto Resistive) isolators made by NVE. I think they work way better than opto isolators.


The important question here is how come an isolator doesn't completely fix things, it seems at first glance that having completely isolated power networks for the digital side and the mixed signal side (I'm calling it mixed signal because there are digital signals (I2S data, clocks) AND analog signals (output from the DAC chips) in the same power domain) should prevent PS noise from going between them. If the power domains were truly isolated they would, BUT the domains are NOT completely isolated, the data is going between them! This is the part that is usually forgotten in these types of discussions.


I hope I can convey what is happening here, let's follow a pulse through an isolator between domains and see what happens. Let's assume a real "dirty" digital side, a lot of ground plane noise and power supply noise, and noise riding on top of the digital signal. Lets look at the isolator, it has power and ground connections on the "dirty" side that run the driver that produces the whatever crosses the "barrier" (light, magnetic field, radio waves, whatever).  The noise also modulates the "threshold" looking at the input signal. These and the noise and jitter in the signal all add up to a pretty large amount of variation in the field crossing the barrier.


On the other side of the barrier you have a much cleaner supply driving the receiver circuit, but the noisy field is going to cause a current in the receiver. Thus noise on the dirty side is going to cause current noise on the clean side as well. The isolator designers try and make them so the physical properties of the receivers have some form of thresholding so this transmitted noise is decreased, but a fair amount still gets through, and it is greater at the low frequency side. But that is not all, the data, the signal you WANT to cross the barrier, also causes current to flow through the PS pins of the clean side of the isolator, and that signal has a lot of jitter on it by now.


When the packet noise on the dirty side of the barrier is low, the current noise of the isolator will be lower, when the packet noise is high, the current noise of the isolator will be high. So even though the power supplies are completely separate, packet noise on the dirty side can still make it through an isolator and show up as current noise on the "clean side". If the PDN is very low impedance over a very wide bandwidth this current noise will produce very little voltage noise. If the PDN is not so great, there will be some significant voltage noise. It usually will be reduced from what it was on the dirty side, but still definitely there.


Yes putting a whole tracks worth of data in ram, shutting down the packet interface, and grabbing the data out of ram at the audio sample rate should help this, but this is frequently done by a processor and it's memory, that processor is usually producing it's own set of current noise which can cross the barrier. To be really effective it would take a system where the source (whatever it is) fills up the buffer then completely shuts down, nothing drawing power AT ALL from then on, the only thing drawing power is the counter walking through the ram and the ram itself. You definitely would want a simple ram structure, not something like a DDR3 DIMM which has all kinds of stuff going on all the time. The data from the RAM goes over the isolator and on to the DAC chip. This would probably be a very effective isolation scheme, but I don't think anybody has actually ever implemented this.


I have been doing some more experiments on this in the last week and have some results to share. I was working with the USB regen Alex mentioned, with the first version I was able to clearly see the packet noise on a scope. I made a new version with an improved PDN, this seemed to work, I could not see any packet noise any more, noise was still there but I could not discern any modulation due to the packet frequency. It sounded significantly better. Later I did some crude PDN analysis and discovered there was a raising in the impedance over a certain frequency range. I figured out I could fix this by adding a single capacitor in the right place. I soldered in that cap and started listening and was startled in the magnitude of the improvement in SQ. The noise looked identical with and without the capacitor, the sound significantly improved.


So I think I am on the right track, but it looks like I have already gone beyond what the simple measurements I was doing could detect. Next is to do these tests with the spectrum analyzer, it will probably be able to detect the packet noise buried in the over all noise floor.


I hope that answers some of the questions.


John S.

There is a thread over at CA here about it too.[/quote]

[jtwrace]

I'm surprised nobody is interested here. 

[JohnR]

Why don't you tell us in your own words? Do you have one?

[jtwrace]

Why don't you tell us in your own words? Do you have one?

No, it's not available yet. 

[JohnR]

Oh right. Any idea of price?

I'm curious as to why splitting the USB cable and using a quiet DC power supply wouldn't be the first thing to do.

[mresseguie]

I only just noticed this thread.

[jtwrace]

Oh right. Any idea of price?

I'm curious as to why splitting the USB cable and using a quiet DC power supply wouldn't be the first thing to do.

Alex (UpTone Audio) is still working on the pricing but hopefully it will be announced soon. 


If the data/power is needed on the dac that is certainly one option but I also think that using a proper cable can be as good too.  Hopefully UpTone will see this and respond as he's better equipped than me.   

[barrows]

I kind of wish Alex went ahead and built this into a cable.  As SI is the principle by which this is propsed to work, adding additional USB pressure connections are not really conducive to getting the best out of it, usually connections like this are not good for the SI.
But, it would probably be a good DIY project to remove the jacks and directly solder in a good USB cable...

[jtwrace]

I kind of wish Alex went ahead and built this into a cable.  As SI is the principle by which this is propsed to work, adding additional USB pressure connections are not really conducive to getting the best out of it, usually connections like this are not good for the SI.
But, it would probably be a good DIY project to remove the jacks and directly solder in a good USB cable...

Well one step at a time. Then if one wants to diy it should be easy enough.

[jtwrace]

Hopefully UpTone will see this and respond as he's better equipped than me.   

Or not. 

[jtwrace]

An update that was posted on CA here.


Hi everyone:


I REALLY love all the interest, enthusiasm, and anticipation for the our USB Regen, but some days I almost regret pre-annoucing it just because keeping up with the e-mails and questions can keep me busy all day!   So thank you for that!


So let me say a couple of things about the "notification list":  If you have ever bought anything from us (a JS-2 or MMK), or if you have ever received an e-mail from me (either personalized or one of my "newsletters"), then you are already on the mailing list.  Once we have boards and cases in hand, you will ALL receive a e-mail to your private address with a photo of everything that will be in the package, along with price and shipping cost.


So those of you for whom I already have an e-mail address, posts or messages to me expressing interest or wanting to reserve one are at the present time not necessary (this is not a crowd-fleecing, er, funding campaign).


However, if you have never sent a message or received any product or message from me, then please message me on CA and include your private e-mail address (I promise never to sell or reveal it anywhere, and my "newsletters" are very sporadic so you won't get a bunch of them). 


You are also welcome to send a mailing list request directly to my crespi@sti.net e-mail address (one would think I would have set up an @uptoneaudio.com address by not, and although I own that domain name, I'll have to wait until I finally set up a web site--promised my wife that would be by the end of March.)




Okay, back to the Regen itself:


With regards to the output connection to one's DAC or other device, it is likely that I will include both a solid male/male A/B USB adapter, AND a 6" A/B USB cable.


Hang tight gentlemen.  It won't be too long.
Thanks and regards,
ALEX

[jtwrace]

Oh right. Any idea of price?

Sounds like < $200

[jtwrace]

Oh right. Any idea of price?

I'm curious as to why splitting the USB cable and using a quiet DC power supply wouldn't be the first thing to do.

Officially $175.  Should have mine in a week or so. 


The site goes public 4/14/15.  The first 100 of them are for people that have sent him an interest email, PM or purchased the JS-2 (power supply). 
http://uptoneaudio.com/


Regen
 

The UpTone Audio USB REGEN just might be the next big leap for computer audio.
The USB REGEN takes the digital audio stream from your computer or other music streaming device, and generates a completely new USB data signal to feed to your DAC.  It accomplishes this by combininga carefully chosen USB hub chip with an ultra low-noise regulator and low-jitter clock.  Importantly, it does so with ideal impedance matching—right at the input of your DAC.
If you are familiar with the variations in sound quality that come from different computer configurations, USB cables, and power supplies (no, "bits are bits" really does not apply when pursuing the audio summit), then you will immediately recognize the often dramatic effect that the REGEN can have on the the connection you feel with the music.
Although the REGEN does not eliminate all sound quality differences between USB cables in a high-end system, it significantly reduces those differences.  John Swenson has written about how the PHY chips and processors at the input of every USB DAC (even those with galvanic isolation) are sensitive to "packet noise modulation" and ground-plane noise—caused by poor signal integrityand impedance mis-matching.  Every USB audio source (computer or streamer) and cable causes this, every DAC is affected by this—and the REGEN is the cure.

The USB REGEN's secondary function is that it disconnects the computer's noisy 5 volt bus power coming down the USB cable, and provides clean 5VBUS on its output--for DACs that need it—via a second ultra low-noise regulator.

From all the time we have spent listening to the REGEN in our systems we can say that it is exceeding our expectations. Often it sounds like you are listening to a different DAC!  Of course the effect will vary some by computer/DAC system, but we hear positive differences even with small systems. The improvement is different than with a power supply or computer optimizations—but perhaps larger.
Regardless of whether you are feeding your USB DAC from a from a stock computer, a fully-optimized music server, or a streamer/renderer (Auralic Aries, Bryston, Moon Audio, SOtM sMS-100, etc.), the REGEN has the potential to carry your music system to a new level.
The USB REGEN kit includes:
a) the REGEN itself in an all black with silver-printed aluminum case (57 x 46 x 18mm); Input is USB 'B' jack, Output is USB 'A' jack, DC jack is 5.5mm x 2.1mm.
b) the best spec'ed and sounding 22 watt/7.5V/2.93A (overkill) tabletop (93 x 54 x 36mm) SMPS we could find (use a nice linear if you want—in the range of 6-9V/1.5A is fine; or even 12V if you are certain that your DAC is not deriving much power from USB bus); If you own an UpTone JS-2 LPS, then you can consider using one of its outputs—set to 7V—to power the REGEN very nicely!
c) an 18-inch long Volex 18awg power cord to go from the SMPS to the wall (get fancy if you like, or if you are overseas use a power cord with locally appropriate plug);
d) a male/male USB A/B solid adapter plug (for hanging the REGEN right from the back of your DAC; maybe stick a block of something under it if you feel it needs support);
e) a 6-inch male/male USB A>B cable if things are too tight around your DAC's USB input or you just don't want to use the solid adapter.
f) a 4-year, transferrable warranty.

[jtwrace]

Mine has landed!


Yes, it's tiny! 
 


 


 

[Nick77]

Very cool, how does it sound right out of the gate?

[jtwrace]

Very cool, how does it sound right out of the gate?

Very very nice. 

[*Scotty*]

You are using this between your Aries and your Vega and it replaced your existing USB cable?
Which was?
Scotty

[jtwrace]

You are using this between your Aries and your Vega and it replaced your existing USB cable?
Which was?
Scotty

Yes but it doesn't replace your USB Cable.  You still need one whether it's copper, silver or optical. 

[jtwrace]

In the words of the designer; John Swenson...


The Wyrd and the regen are conceptually similar from an upper level standpoint, they are very different in implementation and motivation for the development.

From reading what Schiit has posted it seems that their motivation was providing a clean power supply and secondly regenerating the data, whereas my motivation was providing the highest signal quality I could, and secondly providing very clean power.

Some of the differences are:The regen has a much lower jitter clock feeding the hub chip, which will provide lower jitter on the data.

The regen uses a 4 layer board, primarily to allow a proper impedance match. With a standard thickness 2 layer board it is impossible to attain a proper impedance match to the hub chip. The pins on the chip are small and close together, this necessitates very thin board traces, with a two layer board the distance between ground plane and these traces (BTW this is called a differential micro-strip configuration) produce an impedance that is much greater than the spec. With a four layer board the ground plane can be much closer to the top layer which allows for appropriate impedance with the very narrow traces. The regen also uses SMD USB jacks which allow for appropriate trace width and spacing to continue the impedance matching through to the USB jacks. The result of this is that there will be very minimal reflections at the regen side. Even if the DAC does not have good impedance matching (which is pretty common) which WILL cause a reflection at the DAC end, it will be absorbed at the regen because of the proper impedance matching.

The regen has a frequency optimized Power Delivery network (PDN), which turns out to make a very significant improvement in SQ. This is quite a technical subject, WAY beyond what I can post here, but here is the mile high summary:

In order to properly respond to the load variations of what the supply is powering, it needs to have a low impedance over a very broad range of frequencies. For digital audio this is from low Hz to hundreds of Mhz range. The entire supply flow from mains AC to board layout and capacitors on the board play a role in getting this right.

The regen is what got me focusing in on this. I was testing the first prototype and was seeing some noise on the supply right at the hub chip power pins that shouldn't be there. After a lot of detective work I traced it down to some frequency ranges of the PDN that were much higher impedance than they should be. I included a fix for this in the second version. With this I couldn't detect the noise any more, and it sounded much better, but Alex was still not super thrilled with the SQ. I then did a mathematical analysis of the PDN and found another frequency range that had a higher impedance than it should, made a fix for this, and sent the result to Alex, he was thrilled, this was much better than anything he had heard before.

This process of frequency optimizing the PDN is something that is done in expensive high speed network equipment, but is almost never done in consumer products, especially audio equipment. But the experience with the regen seems to point to this being quite important for digital audio. I have subsequently tried some of this on some DACs and seen marked improvement in SQ, so it looks like this might be a significant area to look into.

The whole reason I started thinking about a regen was the USBcable threads, after a lot of experimentation and thinking about it, I came to the conclusion that the signal integrity at the DACwas what was probably the difference between cables. Thus a device designed to regenerate the data signals. Because the whole purpose was to regenerate the signals that the cables were messing up, the regen device had to be right at the input to theDAC, thus it needed to be small and low weight.

One un-anticipated benefit to the frequency optimized PDN, is that the noise on the VBUS output is much less sensitive to load transients than other implementations. So if the DAC IS bus powered, that brings even more improvement.Well there it is, the primary reasons the regen has better implementation than other devices.

John S.

[*Scotty*]

This begs the obvious question, will an optimized server like HALs MS-2 sound similar to an Aries, or are we still listening to the software player in the server, say jRiver 20, which is inferior sonically to the player software in the Aries?
Scotty