Uptone ISO Regen Review and Measurements

[March Audio]

Apparently not.



Maybe they have and you just ignore or dismiss them.



Really? You call a whole swath of rather sophisticated audiophile idiots? And what do you know about what we have or have not verified about our products? That 15 minute chat by the elevator at RMAF two years ago? Good grief indeed!

--Alex Crespi
UpTone Audio LLC

So Alex, can you oblige us with some measurements that demonstrate the positive effect in the DACs analogue output of a regen "cleaning" the USB signal.

For the moment lets ignore power supply and galvanic isolation.

 

[March Audio]

For numerous reasons (including my blood pressure) I do not post here at ASR--and I generally ignore the misguided sideshow, but Amir's latest blunder is just too good to pass up:

https://www.computeraudiophile.com/...-a-dacs-output/?do=findComment&comment=704222

And:

https://www.computeraudiophile.com/...-a-dacs-output/?do=findComment&comment=704286

Alex Crespi
Uptone Audio LLC

With reference to your post on CA, could you explain the difference between an AP analyser which may have a single ended connection to mains ground and an audio amplifier that may have a single ended connection to ground? I presume you understand the reason for the question.

Also, can you explain why you would use a SMPS which creates this problem where Amir demonstrated his linear supply did not?

We wait with anticipation your technical replies.

 

[RayDunzl]

Data Point:

I happen to be making a backup to an external disk right now using a USB 2.0 port and an unidentified but at hand USB cable:

That's 226 x the rate if playing a CD to DAC.

 

[Jakob1863]

Data Point:

I happen to be making a backup to an external disk right now using a USB 2.0 port and an unidentified but at hand USB cable:

View attachment 8074

That's 226 x the rate if playing a CD to DAC.

Which is imo an impressing transfer rate for USB 2, but in which way is that an argument wrt to this discussion?

 

[RayDunzl]

Which is imo an impressing transfer rate for USB 2, but in which way is that an argument wrt to this discussion?

I'll delete it if you find it offensive.

 

[Jakob1863]

I'll delete it if you find it offensive.

Offensive? Why should it be? It´s just a statement and the numbers are nearly correct, but i simply can´t figure out, if there is an implicite argument given or something that should follow as obvious, therefore i ask.

 

[Sal1950]

Data Point:

I happen to be making a backup to an external disk right now using a USB 2.0 port and an unidentified but at hand USB cable:

View attachment 8074

That's 226 x the rate if playing a CD to DAC.

Well there goes the integrity of your files Ray. No USB cleaning or other magic dust, I'm sure your backup is full of noise and sideband distortions.
Hope those files don't have anything to do with your taxes this year, it could mean jail time.

 

[Thomas savage]

Well there goes the integrity of your files Ray. No USB cleaning or other magic dust, I'm sure your backup is full of noise and sideband distortions.
Hope those files don't have anything to do with your taxes this year, it could mean jail time.

No jail time for...,

 

[pinkupanda]

Well there goes the integrity of your files Ray. No USB cleaning or other magic dust, I'm sure your backup is full of noise and sideband distortions.
Hope those files don't have anything to do with your taxes this year, it could mean jail time.

Before filing taxes it would be a good idea to run and clean it up with the Regen though

 

[amirm]

For numerous reasons (including my blood pressure) I do not post here at ASR--and I generally ignore the misguided sideshow, but Amir's latest blunder is just too good to pass up: https://www.computeraudiophile.com/...-a-dacs-output/?do=findComment&comment=704222
And: https://www.computeraudiophile.com/...-a-dacs-output/?do=findComment&comment=704286
Alex Crespi
Uptone Audio LLC

OK, back from the trip and had a bit of time to answer this. I am going to provide two answers. One high level that is easy to understand and should completely do away with this argument. The second answer, will be a deep dive into power supplies, emissions control, safety, etc. that explains why the problem is created with ISO regen and not otherwise.

First, here is the argument from the first link above:

In a nutshell, he is saying that because ISO regen uses a switchmode power supply and so does the Audio Precision (how he knows the latter is beyond me seeing how he doesn't have one), and that switchmode power supplies have a "required Y capacitor" that what I am observing with respect to increased mains frequency and harmonics in the output of the DAC as measured by my Audio Precision Analyzer, is unavoidable. He is also pointing to an iFi post which was measurements of their power supply (and not the DAC) as proof point of this.

Here is the diagram for how I measured the Behringer UMC204HD as is:

Right away we see the flaw with the statement Alex is making. There are plenty of switchmode power supplies in my playback and measurement chain. The Behringer was powered by the USB power of my desktop workstation. This is a custom PC I built with a switchmode power supply. I don't pretend to know what power supply configuration is used in the Audio Precision Analyzer. I do have a laptop connected to it that controls the analyzer over another USB bus and the laptop was connected through yet another switchmode power supply to mains.

So if switchmode power supplies have "required Y capacitors" and anything upstream of the analyzer would create mains harmonic noise, it should have been there all along. But it was not at nearly a significant level until I changed to this configuration:

In this configuration, yet another power supply made by a half-decent Chinese/Taiwanese company called Meanwell is added in the middle of the chain. This is powering the ISO Regen which in turn generates a new USB bus power. In this configuration we managed to increase the mains related harmonics as I showed before:

By now it should be obvious that the mere fact there are switchmode power supplies upstream of the DAC/USB bus does not at all say that the measurement scheme is faulty. The only change here was insertion of the ISO regen and it created the heightened noise products in the output of the DAC. Clearly what Alex is saying regarding design and operation of switchmode power supplies is incorrect (I will dig into this in the later detailed post).

But let's say for the moment that he is right. Nothing about that means that we can't measure the output of the system with the Audio Precision Analyzer. The AP acts just like any other audio device. It has an analog pre-amp, power supply for the same, and other bits to capture that stream. There is no law against such an audio having a switchmode power supply. Class-d amps for example mostly have switchmode supply. Is Alex saying that in such configuration ISO Regen does screw up the fidelity of the system? If so, why is that not indicated in the specification for the device?

Last but not least, I suspect the last thing anyone would think of when reading about a device that says it provides isolation, that it actually creates current leakage of its own!

Summary
There is nothing wrong with the testing as performed. Had UpTone bothered to measure the performance of their system with DACs, they would have likely found this issue and hopefully would have re-looked at their system architecture and chose a different design. AC mains current leakage, ground loops, etc. are part and parcel of unbalanced, RCA connections. Fact that adding yet another power supply to what is already a complex configuration causes more mains related distortions should not be surprising. Simplicity sometimes is our friend and ISO regen moves away from that.

 

[amirm]

For numerous reasons (including my blood pressure) I do not post here at ASR--and I generally ignore the misguided sideshow, but Amir's latest blunder is just too good to pass up:https://www.computeraudiophile.com/...-a-dacs-output/?do=findComment&comment=704222

And:https://www.computeraudiophile.com/...-a-dacs-output/?do=findComment&comment=704286

Alex Crespi
Uptone Audio LLC

Dealing briefly on the second link:

It is remarkable to me that all these words are thrown out without one ounce of instrumentation! Oh there is leakage current? How much? Where did you measure it? How many DACs did you measure?

Then there is bit on LPS-1 solving these problems. Where is the instrumentation on that? If you know it "blocks the path of leakage current" surely you have measured those things and can post them.

Engineers instrument their designs and verify their operation. The school of thought here is to just hypothesize them and say they are solved!

Folks have a hard time accepting my real data but go by what Alex says in just words?

Until instrumentation is provided, folks should be on guard with respect to these word arguments.

 

[Fitzcaraldo215]

My jaw dropped, too, when Alex went into typical CA alternative facts mode by citing the "known but little understood" problem of current leakage, which somehow applied to Amir's test setup, but not to any audiophile's system. And, lo and behold, there were once again only words and hand waving, but zero in the way of measurements to back Uptone up.

Uptone and many others get away with it over and over at CA, the deluxe new version updated for the 20xx generation of good old fashioned BS snake oil.

 

[March Audio]

As I alluded to earlier and Amir stated above, Alex and Uptone seem to miss the point that the AP is no different to having an audio amp in the chain. If you see a problem with the AP you are very likely to see it with an audio amp. If only Uptone were technically professional enough to measure their products in real situations instead of just theorising about their actual real world performance then they would have spotted the issue.

I have asked Alex above to provide some measurements demonstrating how the Regens USB "cleaning" improves the DACs analogue output (ignoring power supply and galvanic isolation). We will see if there is a response.......well we know there will be.......to the fanboys on CA

 

[amirm]

BTW, I asked Alex, who makes the IR, if it would make a difference on a unit that was already galvanically isolated. His response was that there was a reasonable chance it could make a small improvement, because in most units the galvanic isolation is internal, and after the actual USB input circuitry (my paraphrase of what he said). So putting the isolation before the USB input could slightly improve results. He didn't claim anything more than that. So far I don't really hear it.

Why, oh why, would you believe what Alex told you? Did you ask him how many DACs he has taken apart? Brands and models he has analyzed in this regard? What his qualifications are to even understand the schematic and PCB of a DAC?

I have met Alex. He is a very nice and pleasant man in person. But he absolutely is not technical. He is an audiophile no different than any. Yes, he rubs shoulders with John so picks up some of the terms here but this is not his domain.

Further, why did you not ask him for some quantification here? Have him show why galvanic isolation before or after USB have different impacts?

Why would isolation prior to USB be superior? Why would sticking an outboard wall wart on said isolator be a good thing when they come right out and say it generates mains current leakage? Don't you think if I designed that internally in a high-performance DAC, I can avoid that?

I am just amazed how much willingness there is to just accept word arguments. It seems all folks need to do is throw some technical terms in there and people bow and go and shell out hundreds of dollars.

So no, he did claim *a lot*. None of it backed by anything other than he says it, so it must be true. Why is your guard so low with him and so high with me?

Alex did not give me his background. Here is what he has said in public: https://www.linkedin.com/in/alex-crespi-a6257624/

Again, he is a nice guy and I should add, master of Internet marketing. But please keep in mind that nothing this company has produced as ever passed objective scrutiny.

Take JA's measurements/assessment of Regen *even while using a very long USB cable* :https://www.stereophile.com/content/uptone-audio-usb-regen-measurements

"Using this long cable and my MacBook Pro running on battery power, I tested the Regen with a PS Audio PerfectWave DirectStream DAC and a Meridian Prime D/A headphone amplifier, using my Audio Precision SYS2722 analyzer and the same test signals I'd used for the JitterBug review. Sad to report, I found that the Regen made absolutely no difference in the D/A processors' analog output signals. With one exception: the levels of the power-supply–related spuriae in the Prime's output when powered by its wall wart were slightly higher in level with the Regen than without it."

It mirrors my finding here (and for the original Regen).

I know it is hard to put aside lifelong learnings as an audiophiles but you must do so. The facts are overwhelming here.

 

[amirm]

And it is not just Alex but also his designer, John. Here is his response to Stereophile regarding their measurements: https://www.stereophile.com/content/uptone-audio-usb-regen-manufacturers-comment

"Measuring the signal integrity of the USB signal is something fairly easy to do with a 3–4GHz scope and an eye-pattern test. Jitter measurements are a lot harder[;] at the exceedingly low level we are looking at[,] it takes some rather expensive test equipment. Unfortunately[,] where a lot of the final jitter happens is inside the DAC chip[,] and that is essentially impossible to measure.

"None of the standard audio tests have been able to find any difference in the analog audio output. Part of the problem here is that in order to make any sense, the analog-to-digital converter used in the test equipment must have lower jitter than the jitter you are trying to measure the effects of. People doing these measurements are using ADCs that have known jitter levels significantly greater than what the best DACs have. This makes these tests pretty useless for measuring the supposed effects caused by changes in jitter."

This is of course completely incorrect. As people have seen from my measurements and JA's in stereophile we have no problem digging into jitter created in DACs. Our measurements systems use software post-processing and high performance ADCs which have no trouble at all to detect jitter well below any threshold of hearing.

John has never used an audio analyzer and is not familiar with the signal processing concept here so makes a bunch of assumptions that simply do not hold water. How does he think people design DACs with no way of measuring their performance???

Again, I have met John and he is a delightful engineer. He just doesn't know a lot of these concepts as they are not part of his career. He makes guesses, goes and puts solutions forward with no measurements or confirmation objectively that they work. Instead, he relies on likes of Alex to tell him in subjective sighted listening, that things got better. That faulty feedback loop has guided him onto a path that I don't think he himself realizes how wrong it is.

We are talking about topics here that require exceptionally broad set of knowledge and experiences. People need to be careful to not rely on opinion of others not schooled in them all with no objective data to back any of it.

 

[amirm]

Here is some data to back what I said above. This time I have measured it with Prism Sound Analyzer which is a competitor to Audio Precision Analyzer. It is the jitter performance of my 20 year old Mark Levinson No 36S DAC:

Notice how it is showing peak spikes at a whopping -132 dbFS!!!

And here it is with the results of Peachtree Decco DAC overlaid on top of it:

See? We have no problem telling them apart at such low levels of errors.

Here is the Decco again this time comparing its own USB input to audiophilleo USB/SPDIF converter driving its S/PDIF input:

We can see how the Audiophilleo in green is superior.

So if the ISO regen had done anything of the sorts, we would see it.

 

[Thomas savage]

Thanks amir ( my iPad just autocorrected amir to amazing, Amir did you hack my iPad to make this happen? ) that's clear and informative, I look forward to a reply in kind by somebody from uptone.

I'm not particularly interested in word arguments, I think we need data here rather than any " but my dad's tougher than your dad" type responses .

 

[Blumlein 88]

Thanks amir ( my iPad just autocorrected amir to amazing, Amir did you hack my iPad to make this happen? ) that's clear and informative, I look forward to a reply in kind by somebody from uptone.

I'm not particularly interested in word arguments, I think we need data here rather than any " but my dad's tougher than your dad" type responses .

You just say that because Alex of Uptone is SUPERDAD!

I agree, would be nice to see data from Uptone or other parties.

 

[Purité Audio]

Thanks A informative, eductational and entertaining .
Keith

 

[March Audio]

And it is not just Alex but also his designer, John. Here is his response to Stereophile regarding their measurements: https://www.stereophile.com/content/uptone-audio-usb-regen-manufacturers-comment

"Measuring the signal integrity of the USB signal is something fairly easy to do with a 3–4GHz scope and an eye-pattern test. Jitter measurements are a lot harder[;] at the exceedingly low level we are looking at[,] it takes some rather expensive test equipment. Unfortunately[,] where a lot of the final jitter happens is inside the DAC chip[,] and that is essentially impossible to measure.

"None of the standard audio tests have been able to find any difference in the analog audio output. Part of the problem here is that in order to make any sense, the analog-to-digital converter used in the test equipment must have lower jitter than the jitter you are trying to measure the effects of. People doing these measurements are using ADCs that have known jitter levels significantly greater than what the best DACs have. This makes these tests pretty useless for measuring the supposed effects caused by changes in jitter."

This is of course completely incorrect. As people have seen from my measurements and JA's in stereophile we have no problem digging into jitter created in DACs. Our measurements systems use software post-processing and high performance ADCs which have no trouble at all to detect jitter well below any threshold of hearing.

John has never used an audio analyzer and is not familiar with the signal processing concept here so makes a bunch of assumptions that simply do not hold water. How does he think people design DACs with no way of measuring their performance???

Again, I have met John and he is a delightful engineer. He just doesn't know a lot of these concepts as they are not part of his career. He makes guesses, goes and puts solutions forward with no measurements or confirmation objectively that they work. Instead, he relies on likes of Alex to tell him in subjective sighted listening, that things got better. That faulty feedback loop has guided him onto a path that I don't think he himself realizes how wrong it is.

We are talking about topics here that require exceptionally broad set of knowledge and experiences. People need to be careful to not rely on opinion of others not schooled in them all with no objective data to back any of it.

OMG did he really say that!?!?!?!?!? Technically incompetent. Followed by admitting his product does nothing. hahahah.


So lets get this straight, according to Swenson the jitter his product allegedly fixes is impossible to measure. So, can he explain precisely how he has verified the Regen fixes this unmeasureable problem?

People actually fall for this? Really?