USB audio cracked... finally!

[fas42]

11 minutes ago, Ralf11 said:

Are you an engineer?

 

Yep. An EE, from Sydney uni - I got side tracked right at the beginning of my working life, got caught in the web of IT - and never left that field. But I enjoy dabbling in the in and outs of electronics, always have - and audio was something that got my motor running ... .

[mmerrill99]

2 minutes ago, fas42 said:

audio was something that got my moter running

I knew it - a motor mechanic - I could smell the axle grease from  here

[Ralf11]

Sydney?

 

that would be digital chuttering then, as the bits will be upside down

 

motor mechanics are very useful to Ferrari owners...

[fas42]

Interestingly, I approached getting my audio to sound better very much like a mechanic, back then. It was pretty reasonable already, and I just tweaked the rough edges to get it to "run more smoothly". Lo and behold, this did the trick, and everything since has been a logical extension of that approach.

[bibo01]

@PeterSt, what's the impedance of this cable? Have Lush and Clarixa the same impedance?

[marce]

15 hours ago, mmerrill99 said:

Just for some feel for all of this - this youtube video helps to show some issues with USB 3 supersepeed signal (5GHz) in a real world Icebox raid box USB 3. This is that Oz guy EEVblog 'messing around' with a $140,000 12GHz scope to measure.

 

I have linked to the point in the video where he starts to look at the eye pattern.

There are some interesting issues shown on this - admittedly USB 3 with a not optimal probes (about $12,000 for a differential probe)

 

I would draw attention to the very tight eye (the blackish area in the scope) in the scope plots. But also look on the color grading shots & see that there are times when the slope of the signal is way out of spec - shown by green dots in this blackish eye area - as the capture time increases these dots show more & more, beginning to fill in the blackish area - signifying that there are random signal waveforms which are very far off where they should be (you will need to use full screen display to see this)

 

Look also at the difference between the transmit USB eye pattern Vs the USB receive pattern & notice the overshoot & ringing on  the receive pattern

 

There are many other aspects worth talking about that Marce might want to comment on?

 

 

Not surprising it is a 5GHz signal, probe loading alone will have a large effect... This speed isn't required for audio, and as can be seen I would probably add more issues. USB 3 is a bit of a mongrel, extra data lines clagged to the interface, great for disk reading etc where packets can be checked, but it hasen't grow up like Ethernet did.

Just got up and off to work so be back when I have caught up.

[mmerrill99]

1 hour ago, marce said:

Not surprising it is a 5GHz signal, probe loading alone will have a large effect... This speed isn't required for audio, and as can be seen I would probably add more issues. USB 3 is a bit of a mongrel, extra data lines clagged to the interface, great for disk reading etc where packets can be checked, but it hasen't grow up like Ethernet did.

Just got up and off to work so be back when I have caught up.

Yes but I wonder how well it represents the real world i.e. a typical USB cable - remember he is using a $12,000 12Ghz probe & cable admittedly with some soldered on header test points.

[PeterSt]

1 hour ago, bibo01 said:

@PeterSt, what's the impedance of this cable? Have Lush and Clarixa the same impedance?

 

Hi bibo,

 

The answer to this can't be given reliably because of the things "manipulated". So FYI : For Clairixa too I can not guarantee by 100% that it is 90 Ohms because as usual I lack the $$$$$ equipment to measure impedance. All I can do is my stinking very best to apply all little rules to have the complete cable (including connectors and connections and sleeve and all) at 90 Ohms. And say that this is audible by its accuracy (sorry for the word but this is just how Clairixa comes across audibly).

With the Lush the approach has been very different and there it no reason it should be 90 Ohms.

 

I hope you dig my answer. 

[Superdad]

14 hours ago, PeterSt said:

 

I agree with this (assumed you don't know me much). So this is how I will provide those measurements which only will be eye diagrams.

And next it won't tell a qualitative thing, except it will show different from the others. It was made to do so. Haha.

Read more  

 

Hi Peter:

Sadly, the traditional (at least with the 100+ audio engineers I have met in my lifetime) approach of theory, experimentation, testing, listening (all in circular and cross concurrent patterns) will never satisfy those here who either don't have the music system/room to discern the thousands of subtle things that add up, or who refuse to believe that the ear/brain is one of the most sensitive and directly relevant test instruments available.

(Hey, I never write such long sentences but that one seems to work. )

 

Heck, I even began the ISO REGEN Listening Impressions thread by posting before and after eye-patterns.  So we proved our device does one aspect of what we claim (massively improve signal integrity), and then a hundred+ people have been posting detailed reports of what they hear.

 

Yet of course that is nothing for those who demand both a full explanation of the mechanism of why the improved clocking, galvanic isolation, and improved SI and impedance match are effective (truth is somewhere in the DAC's PHY as we have said since the very beginning--but hard to measure as it is a dynamic not static system), and also demand we show the effect at the output of the DAC (which even if shown they would not be able to correlate to qualitative SQ).

 

And now we have Amir at the "science" forum measuring for noise and declaring the whole class of products as snake oil delusion.

http://www.audiosciencereview.com/forum/index.php?threads/uptone-iso-regen-review-and-measurements.1829/

 

So we can tilt at windmills Peter, or we can provide products that music lovers enjoy and appreciate.

I know how I'd rather spend my days.  All while my partner John continues research--and test device building--to eventually probe and measure at the heart of why this all is.  But we won't let that slow the pace of product innovation.  I doubt you will either. 

 

--Alex C.

 

P.S.  Please hurry and ship my 0.7m Lush USB cable when you can.

[PeterSt]

42 minutes ago, Superdad said:

And now we have Amir at the "science" forum measuring for noise and declaring the whole class of products as snake oil delusion.

 

Maybe someone can tell the bloke that if you perform a JTest "measurement" it is quite wrong to NOT see anything of the toggling LSB.

 

The "Test" itself makes no sense to me anyway, but someone with so much noise in his system or DAC or whatever, well, does not understand much of it. It also seems that he is not able to control his beloved AP but that is something else.

Thinking errors as such seem to be in each and every sentence.

The main objection I would have is that : if there is no difference to be found, then there thus is no difference. Man, first learn to measure and judge yourself.

 

I already was fighting with him back in 2007 in his AVR WASAPI introduction thread.

[PeterSt]

43 minutes ago, Superdad said:

P.S.  Please hurry and ship my 0.7m Lush USB cable when you can.

 

Next batch goes out tomorrow. Due Friday. 

[Speed Racer]

1 hour ago, Superdad said:

 

Hi Peter:

Sadly, the traditional (at least with the 100+ audio engineers I have met in my lifetime) approach of theory, experimentation, testing, listening (all in circular and cross concurrent patterns) will never satisfy those here who either don't have the music system/room to discern the thousands of subtle things that add up, or who refuse to believe that the ear/brain is one of the most sensitive and directly relevant test instruments available.

(Hey, I never write such long sentences but that one seems to work. )

 

Heck, I even began the ISO REGEN Listening Impressions thread by posting before and after eye-patterns.  So we proved our device does one aspect of what we claim (massively improve signal integrity), and then a hundred+ people have been posting detailed reports of what they hear.

 

Yet of course that is nothing for those who demand both a full explanation of the mechanism of why the improved clocking, galvanic isolation, and improved SI and impedance match are effective (truth is somewhere in the DAC's PHY as we have said since the very beginning--but hard to measure as it is a dynamic not static system), and also demand we show the effect at the output of the DAC (which even if shown they would not be able to correlate to qualitative SQ).

 

And now we have Amir at the "science" forum measuring for noise and declaring the whole class of products as snake oil delusion.

http://www.audiosciencereview.com/forum/index.php?threads/uptone-iso-regen-review-and-measurements.1829/

 

So we can tilt at windmills Peter, or we can provide products that music lovers enjoy and appreciate.

I know how I'd rather spend my days.  All while my partner John continues research--and test device building--to eventually probe and measure at the heart of why this all is.  But we won't let that slow the pace of product innovation.  I doubt you will either. 

 

--Alex C.

 

P.S.  Please hurry and ship my 0.7m Lush USB cable when you can.

 

I don't doubt that Peter's "Lush" cable alters what happens inside the DAC's USB PHY. I don't even doubt that given enough time, he could tune the cable to improve the sound, in his opinion, of whatever DAC he chose. What I doubt is that a "one size fits all" cable would work the same across various DACs many with very different USB implementations.

 

This kind of tuning has no choice but to be trial and error since there is no way to know how the PHY will react to changes in cable specs. Each unique USB interface would need custom tuning. DACs with galvanically isolated USB interfaces would most likely be much less affected by the "Lush" cable since the affects of the "tuning" are blocked from the rest of the DAC.

 

This isn't "naysaying" so much as it saying it doesn't make a whole lot of sense based on the world as we know it. Excuse me if I don't don't take something that makes little sense at face value.

[acg]

5 minutes ago, Speed Racer said:

 

I don't doubt that Peter's "Lush" cable alters what happens inside the DAC's USB PHY.

 

I do doubt that.  Unless Peter comes out and stops foxing (please don't do that Peter!) I have no firm opinion.

 

 

 

5 minutes ago, Speed Racer said:

 

 What I doubt is that a "one size fits all" cable would work the same across various DACs many with very different USB implementations.

 

 

Peter has already said that this is a cable that should work pretty much everywhere.  In the four years I have known Peter (online of course - we are on opposite sites of the planet - including literally hundreds of emails) I cannot think of one thing like this that he has done that is 'dac specific', or 'item specific'.  He just does not think that way and seems to approach development from a theoretical and practical standpoint not from a view to endlessly 'tuning' a particular system.  I hope you can understand what I have tried to write there...it is important.

 

Think about it...lots of satisfied customers with all different kinds of dacs.  The Lush cable is not dac specific.

 

 

5 minutes ago, Speed Racer said:

 

DACs with galvanically isolated USB interfaces would most likely be much less affected by the "Lush" cable since the affects of the "tuning" are blocked from the rest of the DAC.

 

 

That is where you are completely and utterly wrong.  Peters dac is galvanically isolated.  In fact when he developed the Lush cable I believe it was double galvanically isolated (two Phisolators in series).

 

 

15 minutes ago, Speed Racer said:

 

This isn't "naysaying" so much as it saying it doesn't make a whole lot of sense based on the world as we know it. Excuse me if I don't don't take something that makes little sense at face value.

 

I'm not picking a fight, really I am not, but in regards to the quote above "it does not make a lot of sense based on the world as you know it".  It makes sense in Peters world.  It works in mine, and I don't need to know Peter IP to enjoy what it does for my galvanically isolated dac.

 

 

 

 

 

 

 

 

 

[PeterSt]

26 minutes ago, Speed Racer said:

This kind of tuning has no choice but to be trial and error since there is no way to know how the PHY will react to changes in cable specs.

 

26 minutes ago, Speed Racer said:

DACs with galvanically isolated USB interfaces would most likely be much less affected by the "Lush" cable since the affects of the "tuning" are blocked from the rest of the DAC.

 

What is it ? Are you too ignorant ? Are you ever reading my posts (in explicit response to yours) ?

OK, my Dutch will be too difficult for you - and especially too long winded. You can't digest outlays. So here it is in one sentence (and the last attempt to help you ) :

(I am a bit kidding you know, of course)

 

What is altered is the transmitter - you know, that thing which sits in the PC and which should be the same for everyone.

 

(don't read on because it may be too much)

 

If everybody is to have a same USB Transmitter (Transceiver actually) because PCs are to be compliant to USB specs, and I would be able to change the behavior of those transmitters, all in the same way, then nothing changed between your and my PC. Both behave different from before but both still behave the same.

 

Really ... try to digest this. Put it in your memory and don't let go. It is the explanation why it would work out for everybody in the same fashion. OK ?

 

Then : If you - or anyone - can not understand how this is done, then this is fine of course. Nobody will be blamed. You can question everything regarding this.

 

To be honest, there is one thing which is not consistent with this outlay / thinking, and in case someone comes up with it, I will start talking about that right away. So mark this post ...

[PeterSt]

@acg, wow Anthony. You almost get aggressive.

Kidding toohoo ... 

Many thanks,

Peter

[Jud]

50 minutes ago, Speed Racer said:

DACs with galvanically isolated USB interfaces would most likely be much less affected by the "Lush" cable

 

If the Lush affects the signal (not the noise - important), then galvanic isolation won't stop it (unless you have total galvanic isolation from the signal also, in which case you're hearing no music, right?).  In fact by minimizing any impacts on the sound from noise, galvanic isolation might actually highlight whatever's being done to the signal.

[lmitche]

1 hour ago, PeterSt said:

 

 

What is it ? Are you too ignorant ? Are you ever reading my posts (in explicit response to yours) ?

OK, my Dutch will be too difficult for you - and especially too long winded. You can't digest outlays. So here it is in one sentence (and the last attempt to help you ) :

(I am a bit kidding you know, of course)

 

What is altered is the transmitter - you know, that thing which sits in the PC and which should be the same for everyone.

 

(don't read on because it may be too much)

 

If everybody is to have a same USB Transmitter (Transceiver actually) because PCs are to be compliant to USB specs, and I would be able to change the behavior of those transmitters, all in the same way, then nothing changed between your and my PC. Both behave different from before but both still behave the same.

 

Really ... try to digest this. Put it in your memory and don't let go. It is the explanation why it would work out for everybody in the same fashion. OK ?

 

Then : If you - or anyone - can not understand how this is done, then this is fine of course. Nobody will be blamed. You can question everything regarding this.

 

To be honest, there is one thing which is not consistent with this outlay / thinking, and in case someone comes up with it, I will start talking about that right away. So mark this post ...

Peter,

 

From the transmitter (PC side) your argument makes total sense, but there is more as the same argument can be made for the DAC side for 2 reasons.

 

First, It is likely that any self respecting USB DAC manufacturer has made an effort to ensure the DAC meets USB compliance standards. But, where that is not possible, it is also likely that the DAC manufacturer incorporates third party modules or ICs from companies like Amanero and XMOS where that compliance is in effect outsourced to a third party.  The ubiquitous nature of these solutions suggest a defacto standard and therefore consistent set of behavior exist on the DAC side as well. This may not be quite as consistent as the pc side, but consistent nevertheless.

 

If we tally the type of DAC used by those that have responded to this thread after hearing the Lush, perhaps we can test the dac diversity even in this small sample.

 

I, for one, am using a ifi microidsd DAC with dsd512 upsampling in hqplayer. I have observed the same behavior with the Lush cable as Mani describes in his opening posts.

[mansr]

3 minutes ago, Jud said:

If the Lush affects the signal (not the noise - important), then galvanic isolation won't stop it (unless you have total galvanic isolation from the signal also, in which case you're hearing no music, right?).  In fact by minimizing any impacts on the sound from noise, galvanic isolation might actually highlight whatever's being done to the signal.

Not so fast. Firstly, where is the isolation stage? Secondly, how is it implemented? If the USB receiver is isolated from the rest of the DAC, any effects of the input signal shape should be confined to this part of the circuit, the analogue section remaining unaffected. As for the implementation, it could be either transformer based or optical. In either case, the signal seen by the following stage is whatever the post-isolation driver outputs, which is a clean digital signal. If you now say minor defects in the input waveform to the isolator somehow make it through to the output, you're calling Alex a liar regarding his Regen products (and this aspect of those gadgets has been demonstrated to be true). Sorry, you can't have it both ways.

[Speed Racer]

16 minutes ago, PeterSt said:

 

 

What is it ? Are you too ignorant ? Are you ever reading my posts (in explicit response to yours) ?

OK, my Dutch will be too difficult for you - and especially too long winded. You can't digest outlays. So here it is in one sentence (and the last attempt to help you ) :

(I am a bit kidding you know, of course)

 

What is altered is the transmitter - you know, that thing which sits in the PC and which should be the same for everyone.

 

(don't read on because it may be too much)

 

If everybody is to have a same USB Transmitter (Transceiver actually) because PCs are to be compliant to USB specs, and I would be able to change the behavior of those transmitters, all in the same way, then nothing changed between your and my PC. Both behave different from before but both still behave the same.

 

Really ... try to digest this. Put it in your memory and don't let go. It is the explanation why it would work out for everybody in the same fashion. OK ?

 

Then : If you - or anyone - can not understand how this is done, then this is fine of course. Nobody will be blamed. You can question everything regarding this.

 

To be honest, there is one thing which is not consistent with this outlay / thinking, and in case someone comes up with it, I will start talking about that right away. So mark this post ...

 

Too ignorant?? Where is the "flip off" emoticon?

 

The cable can't just alter one side of the USB connection. It will affect the transmitter and the receiver. In any case, not all PC USB chipsets are the same. There are a variety of chipsets out there. Intel alone has several versions for desktops and several versions for laptops. There are at least 2 dozen other USB chipset manufacturers out there and who knows how many chipset versions. Then, you have unique implementations using those chipsets. In other words, not only are there any different chipsets, there are many different circuitry implementations surrounding those chipsets.

 

Are you trying to tell me they all react to your out of spec cable in exactly the same way?

 

I find that difficult to believe. Why? I have seen out of spec USB cables that would work with Computer A and Device A but would not work Computer B and device A. But would work with Computer B and Device B and would not work with Computer A and Device B. All the same cable. Oh, and Device A has the same chipset as Device B but implemented by a different manufacturer.

 

What does this tell us? That USB cables and the devices they connect are part of systems. Chipset combinations make a difference.

 

 

[Speed Racer]

20 minutes ago, Jud said:

 

If the Lush affects the signal (not the noise - important), then galvanic isolation won't stop it (unless you have total galvanic isolation from the signal also, in which case you're hearing no music, right?).  In fact by minimizing any impacts on the sound from noise, galvanic isolation might actually highlight whatever's being done to the signal.

 

Hold on. Affects what signal? The analog signal that is the music is digitally encoded. The "Lush" cable can't change the analog signal directly.  Internal DAC galvanic isolation is supposed to prevent all the crap on the digital input side from affecting the analog side of the DAC. A clean digital signal is output to the I2S bus. What possible mechanism could the "Lush" cable use to color the sound?

[marce]

25 minutes ago, Jud said:

 

If the Lush affects the signal (not the noise - important), then galvanic isolation won't stop it (unless you have total galvanic isolation from the signal also, in which case you're hearing no music, right?).  In fact by minimizing any impacts on the sound from noise, galvanic isolation might actually highlight whatever's being done to the signal.

Sorry to pick your post Jud, but I want to explain again about Galvanic isolation and noise...

GALVANIC isolation isolates current flow, it does not on its own isolate noise, noise can still couple through the isolation barrier, other techniques such as pi filtering, screens  etc. also have to be used.

[PeterSt]

2 minutes ago, mansr said:

If you now say minor defects in the input waveform to the isolator somehow make it through to the output, you're calling Alex a liar regarding his Regen products (and this aspect of those gadgets has been demonstrated to be true). Sorry, you can't have it both ways.

 

Unrelated to what you said before coming to this pose ...

You can call me that liar just the same. Well sort of. Because I plainly tell you that this isolation is not 100% (it's all on the eye-shattering forum).

 

Now related to what yo said :

Try to read what's being told; all this stuff is not blocked by isolation as the misery is re-generated. You mention "optical" as one of the isolation means, which is the foremost worse because of the processing (protocol conversion) it implies. And this counts for about all.

 

6 minutes ago, mansr said:

Firstly, where is the isolation stage?

 

So indeed it is all about that, but at the "micro level". So what needs to be done behind it. And that again incurs for noise (current draw) and there you can easily be back to square one or have made it worse.

[mansr]

3 minutes ago, Speed Racer said:

What possible mechanism could the "Lush" cable use to color the sound?

Never underestimate the power of suggestion.

[marce]

12 minutes ago, lmitche said:

 

 

First, It is likely that any self respecting USB DAC manufacturer has made an effort to ensure the DAC meets USB compliance standards. But, where that is not possible, it is also likely that the DAC manufacturer incorporates third party modules or ICs from companies like Amanero and XMOS where that compliance is in effect outsourced to a third party.  The ubiquitous nature of these solutions suggest a defacto standard and therefore consistent set of behavior exist on the DAC side as well. This may not be quite as consistent as the pc side, but consistent nevertheless.

 

 

One would hope that when moving to USB digital interface to the DACs the manufacturers would have considered the possible noise coming in via the USB interface.

To not follow the USB spec would be both stupid and a bit silly, its two traces from your connector to the USB input pins that have to be at 90R differential, basic basic stuff...

[PeterSt]

17 minutes ago, lmitche said:

From the transmitter (PC side) your argument makes total sense, but there is more as the same argument can be made for the DAC side for 2 reasons.

 

First, It is likely that any self respecting USB DAC manufacturer has made an effort to ensure the DAC meets USB compliance standards. But, where that is not possible, it is also likely that the DAC manufacturer incorporates third party modules or ICs from companies like Amanero and XMOS where that compliance is in effect outsourced to a third party.  The ubiquitous nature of these solutions suggest a defacto standard and therefore consistent set of behavio

 

Hi - This is all appreciated, but I regard different (brands of) DACs to have a too different topology to behave the same in this regard. This, opposed to PC's which may use different chip sets all right but which still have a similar topology.

Side note : each USB port of a PC sounds different already, because of where the MoBo traces pass; we tested (and reported) this the other day.

 

Let me remind you about the software influence. This largely works out the same for everybody, small personal taste "issues" let alone.

 

Do never forget about the bonding of USB to mains earth and in the end the neutral. This wasn't a subject in this thread, but it sure is one and a big one. It allowed penetration via the back

door

oops.

 

Anyway, the above was the lead in to the driver behavior and THAT is a common denominator for sure (Thesycon).

And mind you, the largest part of XXHighEnd is tuning that behavior.

(plus I am probably the only one around with a license to the source code of it)

 

Or am I making it too wild now ?