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Uptone ISO Regen Review and Measurements

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amirm

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Thread Starter #341
Looks like the CA discussions continue to go down the direction which has already been covered:
upload_2017-8-14_11-23-21.png



"the so called "claims" are general in that regenerating the USB signal and galvanically isolating it CAN/does improve SI, mitigate, noise, etc, to the DAC, which can ultimatley improve the overall sound. "

What comes "to" the DAC is not important. What comes out of the DAC is. DACs are designed with huge immunity to USB vagaries. High-end designers go to extreme measures to isolate what they know to be a computer interface. Even low-end ones like Behringer are well aware of such things. It is only in the imagination of non-designers that these things are impossible to do well inside the DAC and are in need of external help.

Our measurements prove what I am saying here, demonstrating that noise did not go down. That in the face of even noisy "SI" the standard DAC actually did better in extracting the USB signal and UpTone Regen.

There is no evidence that we can verify that any sound was improved. FYI I did listen and did not hear any such improvement. If someone wants to volunteer themselves to show that they can hear improvements with Iso Regen, I am very happy at my expense to come and verify such. Until then, that is an empty claim I am afraid. It is all based on lay assumptions of what these devices can do vs reality of audio electronics.

"Why did you and Amir single out Uptone? "

I didn't single them out. I was asked to measure one by a forum member as I have already noted multiple notes here and elsewhere:

upload_2017-8-14_11-29-34.png


This was in an email exchange about a completely different topic. This was my answer:

upload_2017-8-14_11-30-12.png


And this response:

upload_2017-8-14_11-31-10.png


I don't know how anyone could look at this exchange and decide I am out to get UpTone or singling them out.

BTW, this was also the case with the original Regen which member DallasJustice had purchased and wanted me to measure.

Folks on CA forum need to stop looking at me through the lenses by which they make decisions. I am not motivated by emotions, revenge, etc. My money does not grow on trees either and I like to apply it to many things other than these audio bits. But when genuine interest is expressed and with me being uniquely situated to make such measurements with professional equipment, I go ahead and do it.

"What about the 9 other ones? What claims are they making? The claims are very verifiable, tested, and proven to the satisfaction of the 95% who have tested them. These products work."

I don't know about 9 other ones. But I have tested the Audioquest Jitterbug and reported its ineffectiveness just the same:







You want me to test any other? My door is open. Send me a PM and I give you the address to ship them to me for testing. And I will pay return postage out of my pocket.

"The best way to verify what many are conflating these "claims" to be is to "prove" it by subjecting it to RIGOROUS testing which necessitates listening tests. "

That's where I am but I can't find a single one of you willing to help with it. I can't even get one person to tell me which music track is more revealing. Or what setup they exactly used. Or sit through a controlled testing.

So please put aside these empty word arguments and continued PR campaign and lay assumptions. They don't work with me. Step up and be constructive and then we have something.

P.S. I appreciate someone providing this answer to him on CA forum.
 
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"the so called "claims" are general in that regenerating the USB signal and galvanically isolating it CAN/does improve SI, mitigate, noise, etc, to the DAC, which can ultimatley improve the overall sound. "

What comes "to" the DAC is not important. What comes out of the DAC is. DACs are designed with huge immunity to USB vagaries. High-end designers go to extreme measures to isolate what they know to be a computer interface. Even low-end ones like Behringer are well aware of such things. It is only in the imagination of non-designers that these things are impossible to do well inside the DAC and are in need of external help.

Our measurements prove what I am saying here, demonstrating that noise did not go down. That in the face of even noisy "SI" the standard DAC actually did better in extracting the USB signal and UpTone Regen.

There is no evidence that we can verify that any sound was improved. FYI I did listen and did not hear any such improvement. If someone wants to volunteer themselves to show that they can hear improvements with Iso Regen, I am very happy at my expense to come and verify such. Until then, that is an empty claim I am afraid. It is all based on lay assumptions of what these devices can do vs reality of audio electronics.

"Why did you and Amir single out Uptone? "

I didn't single them out. I was asked to measure one by a forum member as I have already noted multiple notes here and elsewhere:

View attachment 8143

This was in an email exchange about a completely different topic. This was my answer:

View attachment 8144

And this response:

View attachment 8145

I don't know how anyone could look at this exchange and decide I am out to get UpTone or singling them out.

BTW, this was also the case with the original Regen which member DallasJustice had purchased and wanted me to measure.

Folks on CA forum need to stop looking at me through the lenses by which they make decisions. I am not motivated by emotions, revenge, etc. My money does not grow on trees either and I like to apply it to many things other than these audio bits. But when genuine interest is expressed and with me being uniquely situated to make such measurements with professional equipment, I go ahead and do it.

Amir, can you please explain the influence of your SMPS's on your tests as described here?



upload_2017-8-15_8-58-37.png
 

March Audio

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Oh, so now its Audio Precisions fault........

So the Regen power supply causes "AC leakage current over DC connections - in other words its going from the USB ground to the DAC then on the RCA cables to the analyser then through the power supply"

Just like it would to an audio amplifier (esp with grounded shield).

Its interesting to note that a product like the Intona doesn't have this problem because its power supply is properly isolated
 
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Purité Audio

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The Intona I thought a decent product, unfortunately it didn't improve the sound quality of one single DAC I tried it with,
Keith
 

March Audio

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I agree, I haven't found it improve the sound of any DAC Ive tried it with. It does however definitely help in situations where a ground loop is a problem. Its allowed me to source and measure on the same PC for example.

It would clearly solve the Regen problem if inserted in between it and the DAC :) You need to isolate the isolator LMAO :)
 

Purité Audio

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Not buying a 'regen' solves the Regan problem!
Actually the Intona did help one customer who had some DAC with valve output.
Keith
 
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amirm

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Thread Starter #347
Amir, can you please explain the influence of your SMPS's on your tests as described here?

View attachment 8158
First, let me give the punchline that Alex (likely his designer John) later on have agreed that his hypothesis was wrong. Please see: http://www.audiosciencereview.com/f...view-and-measurements.1829/page-15#post-46792

Here is the much longer answer.

Switchmode power supplies due to their nature of turning on and off, create tons of electromagnetic interference (EMI). This switching noise starts at Kilohertz frequencies but goes way up to megahertz due to its high power and decomposition of a square wave (odd harmonics forever). In western world, such devices must limit this kind of interference or they are not legal to sell.

What is bad is that the radiofrequency energy actually comes out of the DC wire of the power supply! Even though the switching is before the isolation transformer, there is enough capacitance to let high frequencies to travel across that isolation barrier and as such, make the DC wire as an antenna radiating everywhere.

Turns out there is a very cheap solution to the problem. You put a capacitor from the output of the power supply to its AC input. The impedance of the input is pretty low for high frequencies and as such, it works to substantially reduce the radiated energy.

Now, you don't want that capacitor to ever fail short because if it does, it will connect the AC input to output representative massive risk of shock/death! For this reason, special safety capacitors called "Y" (and "X") capacitors are used here which in failure mode, become open (there is a film in there that burns through). So if there is an incoming surge on the AC line, all that happens is that you lose your EMI reduction above.

Now you know why the "y capacitor" reference has been used time and time again.

Here is the issue with the Y capacitor though. It not only takes the output noise and dumps it in the input, but also works in reverse, allowing some (small) amount of AC mains current to travel the other way onto the output of the DC power supply.

There are regulations on how much is allowed before there is a risk of shock. If you ever touch an appliance and you get a "buzz", that is the leakage current that is allowed. That is, it doesn't kill you so it is OK.

Problem we have in audio is that we have "single-ended" equipment, i.e. RCA Jacks. This means that the reference for the signal, i.e. what is "zero," is the chassis of the equipment. This is a bad architecture and the reason people sometimes get hum. Getting rid of that hum requires that we stop the current flow between the chassis of the two pieces of equipment. Because once it flows, it is indistinguishable from audio signal itself.

In the case of switchmode power supply as used in this context is that it is already anxious and ready to pump out AC current. By design, it is "leaking" current and it is doing so on the ground pin of the DC connector which becomes the ground of the audio circuits.

Wow. Are you with me still? :)

Now let's get into Alex's hypothesis that there is a switchmode power supply in the Audio Precision Analyzer and hence, it also contributes the same problem. The fundamental problem with that theory is that he doesn't know it is using a switchmode power supply for its operation. I don't either. But this becomes immaterial if you read further.

If you have read this thread fully, you will see that I tested sources powering my USB DAC like my main computer and laptop which too have switchmode power supplies. These supplies showed none of the AC leakage.

The reason they did not is because they have better designed power supplies than the $10 wall wart supplied here. Putting in the Y cap above is a hack, an effective one but still a hack. It allows the power supply to have lots of noise to start, and then tries to filter it. A better but more expensive solution is to use other power supply topologies that have far less noise (e.g. switch when the current is zero). To that end, if the AP has switchmode power supply, it too would be of highest quality by nature and not source of its own leakage.

Now, the theory that Alex/John put forward was even more complex than this. They were attempting to say -- poorly I might add -- that not only there was leakage in the AP but that it was adding to the ones contributed by their supply. Well, this was easy to test for as I have an AC power generator that lets me program its frequency. So I set that to 70 Hz and let the AP run at 60 Hz. That way, the AC leakage contribution would be different from each other. The result resoundingly showed the leakage to be entirely that of 70 Hz and hence, the power supply that came with Iso Regen:



It is true that if we had used balanced system, we would not worry about this. But 99% of the people are not. If your amplifier/pre-amp is connected to the DAC using RCA jacks, then you would see the exact the same leakage as my Audio Precision Analyzer sees.

Summary
Cheap switchmode power supplies employ filtering that by design creates AC current leakage. In typical unbalanced (RCA) audio systems that we use, we are highly susceptible to such leakage because it establishes the reference for our audio signal. As such, this leakage current travels all the way through the DAC and presents itself on its output.

Solutions are to use linear power supplies, avoid these devices if they present no other value, or much better switchmode power supplies.

None of this points to a flaw in the design of the test fixture that I am using. I am on purpose emulating what happens in real life.

P.S. Welcome to the forum. :)
 

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amirm

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Thread Starter #348
BTW, this is an opportune time to show why the iFi's counter to my measurements of microRendu demostrating the same leakage problem was wrong. Here is their write up: https://www.computeraudiophile.com/...o-about-nothing-part-4-uploaded-and-complete/

Note this:

"At AMR/iFi we have a fairly complex setup with multiple isolation transformers separating AP2, Host PC and the Audio device being tested. Overall this setup massively reduced the tendency for instrument ghosts but took an age to develop and then extra time and a chunky budget to arrive at a completely safe, reliable package.

Any AP2 and PC just plugged into common mains does MUCH worse. We’ve been there, done that. Got the t-shirt and the key ring."

So what are they doing? They completely isolating the Audio Precision analyzer such that it cannot see/shunt the AC leakage current from their power supplies! That is why their measurement graphs show no AC mains contributions.

In other words, they are never measuring what happens in *your* audio system.

Isolating and floating the Audio Precision analyzer is also very dangerous. It means that should it develop a short to its chassis, there is no ground path to trip the circuit breaker!!!

And it is not just me saying it. Every skilled engineer will tell you the same thing. Here is Tektronix which is the top two electronics measurement/instrumentation company in the world:



See the last two rows in red.

BTW, those isolation transformers you see on Amazon, ebay, etc. do NOT isolate ground for this reason. To use them as iFi says requires modifying them to defeat the ground wire that goes from input to output.

Now, if you read instructions for measuring power supplies, you often see that they say to provide such isolation. That is fine if you are trying to sell a power supply and AC leakage current is not a concern. For us though, in audio, that is absolutely a concern for us. We want to know if there is AC leakage current because per previous post, our systems unfortunately incorporate that in our audio signal chain.

Net, net, everything iFi said in that write-up was to deflect a problem that is theirs, and make it that of ours.

And you don't have to take my word for it. Here is them saying the same thing:

upload_2017-8-15_10-20-23.png



See? Right there it says that the same leakage occurs in audio systems with PCs and multiple pieces of audio equipment.

Finally, here are the results of my measurements of SOtM SMS-200 networked audio player: http://audiosciencereview.com/forum...w-of-sotm-sms-200-network-player-part-1.1846/



See how much worse the iFi iPower is in exactly the same setup. It is actually performing worse than the stock cheap power supply that came with SMS-200.

So many people have run with their defense without pausing for a moment and asking questions. I mean how many of you use a true isolation transformer on your pre-amp??? Why would you accept their argument when they say in black and white that is how they measure their power supplies?

There is a reason high-performance audio products are built in large boxes with linear power supplies and not powered by these cheap wall warts. It is through that kind of integrated design that you can make sure you are not creating leakage current.

OK, I feel better now. :)
 

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...He is doing science like tests that don't rise to the level of scientific proof...
Your use of the phrase "scientific proof" shows a fundamental misunderstanding of the scientific method. Measurements merely test a hypothesis (or model or theory) for consistency. Strictly speaking, they don't "prove" anything. Every scientific, and hence testable, hypothesis is just one possible measurement away from being disproved.

Testing hypotheses, and moving on, is how we learn.
 

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A good example of the measurements ( experiment) shooting down a theory. That's the problem with folks who like to make up elaborate theories but have zero desire to test them out in practice.
No need for all that if you have a hungry customer base that will buy into any good subjective spin.
 

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I suspect that analog components that suffer from 'Y' capacitor problems, would also do poorly with the John Windt 'Hummer Test". It's all part of the pin #1 problem.
 

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It is true that if we had used balanced system, we would not worry about this. But 99% of the people are not. If your amplifier/pre-amp is connected to the DAC using RCA jacks, then you would see the exact the same leakage as my Audio Precision Analyzer sees.
Really? 99% of DACs and preamps don't have balanced XLR outputs and inputs? Where did you pull that statistic from?

And why are you still going on about the basic facts of SMPS?

And by the way, quite a few DACs with built in power supplies are using SMPS units (with leakage of one degree or another).

And typically, the bigger the supply, the larger the leakage. At least that is what we have found with giant pile of SMPS units we have tested. Of course one can get lower-leakage "medical" units.

BTW, contrary to what you wrote, floated-secondary isolation transformers are quite safe. TV repairmen have been relying on them that way for safety for 70 years.
 

Superdad

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Its interesting to note that a product like the Intona doesn't have this problem because its power supply is properly isolated
Well that's pretty funny since the Intona does not have a power supply. It is 100% bus-powered. And it uses a DC-AC switching converter to get the 5V across the moat through a transformer, then on the other side diodes and a linear regulator with 150 times the noise of the LT3042 (world's lowest noise regs: RMS Noise: 0.8μVRMS (10Hz to 100kHz), spot noise: 2nV/√Hz at 10kHz, PSRR: 79dB) that we use 5 of in the ISO REGEN. Plus, from a standard USB 2.0 port the Intona can not provide more that about 300mV of bus power, well short of USB spec (whereas the ISO REGEN can provide up to 1A for devices that need it.) And they put their cheap clock on the dirty side of the "moat."

You personally may not be able to hear the quality of the Crystek CCHD-575 that we splurge on, but I and lots of other people can. Take a look at the recent upgrade offered to microRendu users. Only change to the board (V1.3 to V1.4) was the replacement of the CCHD-3391 with the CCHD-575. And hundreds of users are thrilled with the difference.

Hopefully soon we will be able to produce the graphical proof you all are so desperate for to show you that upstream stuff really does make a difference in the output of the DAC. It will be from a system that reveals more that the general purpose AP.
 

jtwrace

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Only change to the board (V1.3 to V1.4) was the replacement of the CCHD-3391 with the CCHD-575.
Do you think this would be able to be objectively be seen on the output of a dac?


Hopefully soon we will be able to produce the graphical proof you all are so desperate for to show you that upstream stuff really does make a difference in the output of the DAC. It will be from a system that reveals more that the general purpose AP.
This is a bit confusing. The AP and dScope are pretty much a standard in audio testing. If you're developing a new piece of equipment what type of certification will it have and also will you at least do a round robin test? This is how the real world works in testing and standards development (ASTM for example) which is what I do daily.
 

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Really? 99% of DACs and preamps don't have balanced XLR outputs and inputs? Where did you pull that statistic from?
Most of my friends that are into this have SE in their system somewhere. Certainly the HT crowd. In our meet up last year I and another where the only ones with a balanced I/O from start to finish.

I would say the majority don't. As you go up the cost chain balanced I/O becomes more prevalent. With mastering gear it's basically a given. Hence I like to recommend mastering gear vs audiophile gear.
 

Blumlein 88

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Really? 99% of DACs and preamps don't have balanced XLR outputs and inputs? Where did you pull that statistic from?

And why are you still going on about the basic facts of SMPS?

And by the way, quite a few DACs with built in power supplies are using SMPS units (with leakage of one degree or another).

And typically, the bigger the supply, the larger the leakage. At least that is what we have found with giant pile of SMPS units we have tested. Of course one can get lower-leakage "medical" units.

BTW, contrary to what you wrote, floated-secondary isolation transformers are quite safe. TV repairmen have been relying on them that way for safety for 70 years.
Of course they only use the xfmr during TV repair, and one has to be very careful not to touch any part of the Isofmr if one wishes to be safe while working on them. A rather apples and oranges scenario.
 
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amirm

amirm

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Thread Starter #359
Really? 99% of DACs and preamps don't have balanced XLR outputs and inputs? Where did you pull that statistic from?
I said 99% of people don't use balanced interconnects. Even when the DAC for example may have such a connection, they opt instead to use unbalanced connection because their amp is that way.

What do you think the stats are? What DAC do you and John personally use and is it with balanced connections?
 
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amirm

amirm

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Well that's pretty funny since the Intona does not have a power supply. It is 100% bus-powered. And it uses a DC-AC switching converter to get the 5V across the moat through a transformer, then on the other side diodes and a linear regulator with 150 times the noise of the LT3042 (world's lowest noise regs: RMS Noise: 0.8μVRMS (10Hz to 100kHz), spot noise: 2nV/√Hz at 10kHz, PSRR: 79dB) that we use 5 of in the ISO REGEN. Plus, from a standard USB 2.0 port the Intona can not provide more that about 300mV of bus power, well short of USB spec (whereas the ISO REGEN can provide up to 1A for devices that need it.)
And with it, they avoid the problem you ran into by introducing an AC mains supply that injects its own AC current into the path.

As for noise levels, do you have the actual, measured noise levels of ISO Regen as opposed to relying on the linear tech IC specs? As I hope you well know, major source of noise contribution is from layout and design of the circuit. So quoting chip specs is completely improper.

Finally, remember that I am seeing no reduction in noise level in the output of most DACs I tested because they have their own post-regulator onboard. In other words, even when fed non-clean USB power, they create their own (sans Schiit Modi 2).
 
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