Measurements of Sonore microRendu Streamer

[Thomas savage]

Ok from here on in let be know we welcome measurments that established doubt regarding amirs efforts. It's all we want! Amirs measurments are a start of a conversation!! Sadly no others are talking, in fact all they are effectively doing is pulling faces and flouncing like 2 year olds.

These measurements have offended people's beliefs, but the way they have all reacted shows the limitations of thier reason.

Rather than hand waving, recognise the effort made and engage accordingly...

Anything less will be deleted now.

 

[alfe]

Sorry I'm little bit lost with this story of measurement, is it a new generation of processor,ram or whatsoever used? a new technology is in discussion here?
If some guys are buying the story of audiophile motherboard, congratulation that's what we call freedom.
If Amir had different results I'll be seriously doubting of his integrity.

 

[Blumlein 88]

I saw the other post by the iFi guys. Measurements can be tricky of course.

For instance, if you need all the superb isolation to test (which will tell you the limits of the DUT best) yet the DUT will typically not get that level of galvanic and other isolation in use you have another side to consider. A good reason that plenty of basic testing can be good using just a decent ADC. It is a more typical load the device would normally see in its usual service.

Now getting back, the big thing is we only have Amir's measures. Correct or mistaken it has started the conversion and is a starting point. Think a bayesian approach if you will. At least some of the things Amir is seeing would be possible with a basic good sound card. We need others with these devices to test. Some of us can give assistance how to do it. If lots get measures like Amir, and fail to match the lab bench results of iFi (if we ever see them, I mean come on, am I to believe they don't already have them? or are they still searching for just the way to throw poo on Amir's tests and show better ones?), then we have to assume most users of the device aren't getting the best from it. iFi would be well advised to show what is needed. It looks like a better PS for one thing.

 

[amirm]

From my POV, publishing his initial mistake and criticizing a product when he himself wrote that his measurement didn't make sense - shows a rush to judgement and lack of objectivity.

You seem to be misunderstanding the nature of the original tests. I made two points then:

1. Differing level with and without sonore. This did NOT happen because of my measurement system being in error. It happened because of Windows 10 using two different audios stack when playing the identical file locally versus using DLNA. This is precisely what would happen to anyone else doing the same test. And would face the differing volume levels except that they would not know it. Yet they would draw conclusions and stay with that potential falsehood.

It was through extra effort and my knowledge of how the system works that I was able to find not one but two potential ways the two data paths were different resulting in different volumes and noise floor. I was the only one who caught and fixed the latter (dither in Windows audio stack). Folks immediately credited microRendu with reducing the noise floor and rushing to judgement just the same.

I am usually more careful. But got bamboozled by the way Windows 10 works which I had freshly installed. I found, retested and reported the new results. It is those results that we are discussing now, not the old ones.

2. The second problem I found with the first set of tests remains: combination of iFi power supply and microRendu inject substantial amount of mains related noise and distortion into the output of the iFi Dac. No mistake has been found here.

Importantly, I did things that no one that is out to get these guys would do: I volunteered to test with my lab supply which I know to perform excellently in these tests and another linear power supply. I did not have to do either. I could have stopped at just the iFi power supply combination and left it at that. But that is not my motivation or style. Mine is to investigate and help resolve problems. So I used the equipment time and resources I have to narrow the issues here. Instead of microRendu getting full black eye for degrading audio, it is only the combination of iFi and microRendu that is in question now.

Now look at the reaction in reverse. I am rediculed by Alex and John as not knowing how to use my instruments, not understanding basics of circuit theory, etc. Now ifi is joining the bandwagon. Instead of leading with data as I did, they are leading with word arguments and theories regarding my competence. Since you continue to defend them it is your own objectivity is what you need to worry about, not mine.

 

[ceedee]

If the manufacturer didn't already have measurements available, then how could they make claims about the microRendu's lower noise floor with "audiophile" power supplies?

Aside from the iFi power supply debacle, I don't think the measurements are controversial. There is (in all likelihood) no need for an "audiophile" computer, because our regular computers can already do a passable job of putting out a signal. So measurements showing "no improvement" would hardly be a shock to me.

It does tickle me to read reviews from audiophiles saying that this computer makes their music sound better than any other computer. I'm sure we'll see purpose-built audiophile SSDs before long, if they're not already out there.

 

[dallasjustice]

It does tickle me to read reviews from audiophiles saying that this computer makes their music sound better than any other computer. I'm sure we'll see purpose-built audiophile SSDs before long, if they're not already out there.

You should read computer audiophile sometime if you want more tickles. Don't forget that SATA cables matter too!

http://www.computeraudiophile.com/f28-highend-audiopc-sponsored/pachanko-sata-cable-27065/

My favorite:

Over the years I have replaced countless numbers of Pre-Amps, DACs, Power Amps, Speakers, Speaker Cables, interconnects etc. etc. Many of the changes made a difference, none timbre and tonal improvements as did the Pachanko cables...

 

[cjf]

You should read computer audiophile sometime if you want more tickles. Don't forget that SATA cables matter too!

http://www.computeraudiophile.com/f28-highend-audiopc-sponsored/pachanko-sata-cable-27065/

My favorite:

Let's not forget that all veils won't be fully lifted until the Audiophile SATA cable is teamed with an off grid battery powered supply driving a SATA disk elevated on Stillpoint Ultra 6 feet .

 

[amirm]

IFI/AMR says you have a ground loop in your test measurement.

http://www.computeraudiophile.com/f...ower-much-ado-about-nothing-28982/#post555510

Thanks Michael. I am pleased to see the industry try to address this topic. But I am at a loss as to where they are going there. Seems like they are confused about what I have tested. Wish they had contact me prior to writing their multi-part response.

So to bring clarity, here are the two configurations I have tested. Case 1, is their iFi DAC directly connected to my laptop with USB to feed it digital audio, and its only analog output which is unbalanced, to the Audio Precision's unbalanced inputs for measurement:

​

This configuration performs great. As noted, the Audio Precision analyzer is replacing your pre-amp with unbalanced inputs. It would be how I use the iFi iDAC2 in my music system when it is not being put to use here.

Here is the Audio Precision analysis of what was fed to it over those RCA jacks from ifi DAC2:

This was our reference and "control" if you want to be "scientific."

The next configuration was to insert microRendu in the chain. Since it is a networked device, the picture looks busier:

​

The right hand stayed the same: Audio Precision acting as the pre-amp receiving what iDAC2 give it as before. The connection from my laptop to microRendu was over wireless to my home gigabit Ethernet switch. micoRendu was powered with the iFi iPower power supply that I purchases as a package. It was one system or a "black box" in engineering terms. It is exactly what someone in my position would do in their system.

As before, the Audio Precision is standing in for your pre-amp. It is not some special connection or configuration. RCA audio out comes from iFi iDAC2 as before and feeds analog audio to Audio Precision. Audio Precision digitizes that signal and performs a fourier transforms on it which shows its frequency components as reported before:

It is clear that making this configuration change in the chain of audio (and NOT the Audio Precision) has caused these new, correlated, mains related distortion/noise products to appear.

iFi and prior to them, Alex/John seem to be saying I created a ground loop and that is my problem. Their argument holds no water unfortunately. I have done nothing that a customer would not do. My ifi DAC2 only has unbalanced connection. It does not have balanced output for me to have used.

iFi talks about lack of galvanic isolation in Audio Precision. I am sorry but I have not heard of amplifiers with unbalanced analog audio inputs having galvanic isolation. If the combination of iFi Power and microRendu create a ground loop between them (which they may very well do), and that in turn gets through iFi's own iDAC2, then between them they have created a non-performant system. It is indeed one of the perils of adding this class of device which is created by needing yet another power supply.

Regardless, I can't emphasize enough that what I am measuring is what is seen by any pre-amp. Arguments of ground loop being specific to my setup doesn't hold water. If a $600 audio-optimized network streamer can create ground loops when paired with iFi's DAC, they need to fix this. For $600, they could have galvanically isolated the USB output if they wanted. If they have not, and noise is travelling all the way from a power supply, through microRendu, then iFi iDAC2 to my analyzer, then I am not happy about this situation. They need to build a more optimized solution that doesn't create problems that vast majority of customers without instrumentation would be blind to.

Finally, I want to make sure they are absolutely clear that I am NOT, let me repeat, NOT measuring their power supply. I am measuring the output of their DAC. Per above, I am measuring a system, not a component. My read of a lot of their comments about how they use the Audio Precision is that they think I am measuring the power supply. They say things like using transformers in front of the Audio Precision analyzer. I can't imagine them only testing their DACs through transformers. Power supply noise measurements, yes. But not DAC output.

Anyway, I look forward to the rest of their response. Hopefully it has a measurement of the system as I have pictured above. And as always, I welcome all new data, challenges, corrections, etc.

 

[John Kenny]

What's the WiFi connection between your laptop & iFi DAC? I didn't think the DAC had a WiFi receiver?
How is the iFi DAC being powered in the first diagram?
What is the USB connection between laptop & AP analyser doing?
When you used the bench supply - what configuration was it powering?

 

[John Kenny]

What's the WiFi connection between your laptop & iFi DAC? I didn't think the DAC had a WiFi receiver?
How is the iFi DAC being powered in the first diagram?
What is the USB connection between laptop & AP analyser doing?
When you used the bench supply - what configuration was it powering?

OK, I see you clarified your diagram & WiFi has been removed but clarity on my other questions would be good, thanks.
Is there a USB connection on the AP?
I presume the iFi DAC2 in diagram 1 is being powered from USB VBus?

 

[Don Hills]

What's the WiFi connection between your laptop & iFi DAC? I didn't think the DAC had a WiFi receiver?
How is the iFi DAC being powered in the first diagram?
What is the USB connection between laptop & AP analyser doing?
When you used the bench supply - what configuration was it powering?

This is a common tactic of yours, much in evidence in this thread. You ask questions that have already been answered.

1. The Wifi is between the laptop and an AP. The connection to the DAC is via wired Ethernet.

2. From the laptop USB.

3. Ok, that doesn't appear to have been answered. You're not perfect after all - you can't be wrong all the time.

4. It replaced the iFi plugpack in the second diagram.

 

[John Kenny]

This is a common tactic of yours, much in evidence in this thread. You ask questions that have already been answered.

1. The Wifi is between the laptop and an AP. The connection to the DAC is via wired Ethernet.

Really? You should check again!!

2. From the laptop USB.

I already stated this was probably the case, if you checked

3. Ok, that doesn't appear to have been answered. You're not perfect after all - you can't be wrong all the time.

Is there even a USB connection on the AP?

4. It replaced the iFi plugpack in the second diagram.

OK

 

[amirm]

Is there a USB connection on the AP?

Yes, it is a USB to APIB bridge.

 

[amirm]

How is the iFi DAC being powered in the first diagram?

By my HP laptop's USB port.

 

[amirm]

What is the USB connection between laptop & AP analyser doing?

That's how you communicate with the AP. User interface runs on the PC, the rest inside the AP.

 

[amirm]

When you used the bench supply - what configuration was it powering?

It is a replacement for iFi power supply. It has the same two pins and connector and voltage adjusted to match iFi's.

 

[John Kenny]

"iFi talks about lack of galvanic isolation in Audio Precision. I am sorry but I have not heard of amplifiers with unbalanced analog audio inputs having galvanic isolation. "
Amir, do you really think that a measuring device's input stage should be the same as a preamplifier's input stage?

"Regardless, I can't emphasize enough that what I am measuring is what is seen by any pre-amp. Arguments of ground loop being specific to my setup doesn't hold water. "
Really? How many preamps would have a USB connection to the computer as well as RCA connection form DAC that is connected to the computer? What's the ground potential difference between these two grounds going into the AP & how is this ground potential handled within the AP. Do you see any potential ground loop here?

From your statements, you don't seem to understand what you are measuring & how your measurement configuration differs from a playback config.

 

[Purité Audio]

Why don't you submit some measurements John ?
Keith.

 

[John Kenny]

Why don't you submit some measurements John ?
Keith.

What a ridiculous reply.

Does peer reviewing require someone submitting alternative measurements?

Did pointing out Amir's original flawed 8dB difference in his measurements require that alternative measurements be done?

If you can't understand the logic and/or the technical points being made then you really can't add anything to the discussion.

 

[ceedee]

Thanks for the explanation, Amir. You didn't have a Shakespeare reference, movie references, or memes, but I think you made up for that with actual content.

I'm confident that if your measurements are shown faulty, you will accept that and be happy to correct anything that was done wrong. That's the process, after all; others try the same tests and at some point we hope to get repeatable results.

It's interesting to me that those who dismiss your measurements and techniques also unreservedly accept the least reliable and most error-prone measurement of all: uncontrolled subjective listening. That is exactly what has caused this hobby to be in the state it's in, IMO.