Measurements of Sonore microRendu Streamer

[John Kenny]

BTW, why do you think AP provide a ground connection below each of the BNC inputs/outputs arrowed by Amir in his diagram?

 

[Purité Audio]

I look forward to your explanation John when you post your measurements.
Keith.

 

[NorthSky]

No matter how we cut it, this Sonore MicroRendu Streamer product the size of a cigarettes pack is the rage.
It's making the news all over the World Wide Web, and this right here @ ASR is the most popular threads of them all. Chapeau Amir!
The total number of views is still far from 10,000,000 but way ahead of any other threads.
__________

I'm almost tempted to buy one, with iFi power supply, just for the popularity, measurements included and subjective listening tests as well.
I would love to get more professional opinions in Amir's direction, just for confirmation that it's worth experimenting with.
...Guys like Mike (Mivera), and other audio scientists of high caliber.

It's the sum of all the best audio scientists that helps us make informed and best music listening decisions.

We live on a beautiful blue planet and our audio products keep improving for our listening music pleasure.
And they don't cost tens of thousands of dollars, but less than a thou, and tomorrow less than a hundred.

For the true love and art of music listening.

 

[alfe]

Ground loop....how airplane with all the electronics are still flying

 

[amirm]

Does it really have to be explained that if you want to attempt to measure such low level signals/noise with any degree of veracity then you have to be scrupulous about sources of noise within your measurement configuration. Have you? You are using single-ended connections between DAC & AP (RCA to BNC) - which means you are using directly connected grounds, not floating grounds.

And where is that floating ground in your pre-amp John that is connected to the DAC? There isn't one, right? The audio precision acts just like your pre-amp would. If a ground loop is created in the ifi iPower and microRendu setup, you would have one just the same with your pre-amp. Ergo, I am measuring what real systems work like, not a hypothetical one you are making up. We care about system performance, not component. That is what generates sound.

Unbalanced connections are the most prevalent interconnect in audio. You seem to be thinking no one should measure them as such. Total confusion.

You also have another ground connection through the USB APIB bridge, between laptop & AP. All devices that plug into mains may have ground connections. All of these channels can be ground loops & introduce ground noise issues.

Again, just like your audio system. Every audio component has its own power supply and independent system. My laptop and AP also have two different power supplies, yet no "ground loop" was generated. A perfectly working system was broken with insertion of microRendu and iFi iPower. Why it was broken, ground loop or otherwise, is something for them to investigate and fix. If they cannot fix it and as a result say that additional means are created for ground loops to develop then this is a big cautionary note for users. Adding more moving parts to fix what is not broken is not a good idea.

What checks or balances have you implemented in your measurement setup to mitigate against possible ground loops?

What do you have in your audio system just the same? None I imagine would be your answer. You really have no argument here John. It is not like you have even shown to have been a ground loop here. In identical situation, two different power supplies had no issues with microRendu and my measurement system.

What measurements have you taken to ensure that what you are seeing in your measurements are not due to noise conducted via these ground loops? Any high school student would be asked the same questions based on their presenting such measurements.

I am measuring the output of the DAC just like when it was directly connected to my laptop, "ground loops and all." As I said, you are seriously confused about audio measurements of unbalanced systems. Show me a single review of unbalanced connections in Stereo Review where JA used isolation. You won't find any.

You are also overly focused on the iFi issue. This product claims to lower noise floor. How come noise floor was not reduced under any condition? Do you have any measurements that show noise floor is lowered?

 

[Deleted member 65]

No matter how we cut it, this Sonore MicroRendu Streamer product the size of a cigarettes pack is the rage.
It's making the news all over the World Wide Web, and this right here @ ASR is the most popular threads of them all. Chapeau Amir!
The total number of views is still far from 10,000,000 but way ahead of any other threads.
__________

I'm almost tempted to buy one, with iFi power supply, just for the popularity, measurements included and subjective listening tests as well.
I would love to get more professional opinions in Amir's direction, just for confirmation that it's worth experimenting with.
...Guys like Mike (Mivera), and other audio scientists of high caliber.

It's the sum of all the best audio scientists that helps us make informed and best music listening decisions.

We live on a beautiful blue planet and our audio products keep improving for our listening music pleasure.
And they don't cost tens of thousands of dollars, but less than a thou, and tomorrow less than a hundred.

For the true love and art of music listening.

&Northsky,

Pls, pls tell me what you're smoking/eating, I need you're recipe ...

 

[NorthSky]

Tequila sunrise.

 

[Deleted member 65]

Tequila sunrise.

+Great, I'm a Czech/German beer lover but I do understand and appreciate the instant effect of the above drink.
/Lars

 

[Mivera]

So anyways now that we are through with the measurements, how did it sound? Did you try it with music?

 

[amirm]

I look forward to your explanation John when you post your measurements.
Keith.

He doesn't know how I am afraid any more than others. This is what someone forwarded to me posted on WBF by John:

I love the irony of this post from Amir on ASR "So to bring clarity, here are the two configurations I have tested."
He then proceeds to confuse matters in his two diagrams:
- His original diagram shows a Wifi link (now corrected - he removed Wifi) between laptop & iFi DAC2?? DAC doesn't have a WiFi connection
- he shows a USB connection between laptop & AP?? AP doesn't have a USB connection, AFAIK

Is this clarity? Does Amir ever do any sanity checks? Anybody who has been involved with scientific measurements knows this is a very basic self-test.

AP doesn't have a USB connection? What the heck is he talking about? Audio Precision box, other than one speciality portable unit, has no user interface. All the software for interacting with the machine is done through a computer connected via USB. Here is the manual for the AP which he did not bother to look at, let alone have knowledge of its operation:

"Analyzer Input signals:
Analog signals Audio input signals are acquired using precision interfaces and eventually digitized. The data goes through some initial processing in the hardware, and then is streamed up the USB cable to the PC."

He has looked at the front of the unit and not seen a USB and thinks it works by magic. Here is the manual showing the rear connections with USB within:

So please stop it John. From here on I will be deleting any more of these repetitious, knowledge-free word arguments you are putting forward. You are just adding noise to the thread. Spend the time instead learning how measurement systems work.

 

[amirm]

So anyways now that we are through with the measurements, how did it sound? Did you try it with music?

As I noted earlier, it broke and no longer recognizes my DAC. I have to ship it back to them for them to analyze the problem. So I can't do more testing on it for a week or more at this rate.

 

[Mivera]

As I noted earlier, it broke and no longer recognizes my DAC. I have to ship it back to them for them to analyze the problem. So I can't do more testing on it for a week or more at this rate.

Doesn't the OS run on microSD? Couldn't they simply send a new image to copy on it or a new microSD card?

 

[Mivera]

For the Superstream I'm going to setup a download portal where owners can download the latest OS image to copy on the SD card at anytime. It will be updated weekly.

 

[Deleted member 65]

For the Superstream I'm going to setup a download portal where owners can download the latest OS image to copy on the SD card at anytime. It will be updated weekly.

Right, any 230V EU version?

 

[Mivera]

Right, any 230V EU version?

It will run on any voltage available on the planet.

 

[Purité Audio]

Mike you will send a SuperStream to Amir for measurements ? You can send mine if you need to.
Keith

 

[Blumlein 88]

Show us your measurements John, we are all anxious to see your results.
Keith

Please.....

John is a DAC designer. He doesn't need to do any measurements.

 

[amirm]

Doesn't the OS run on microSD? Couldn't they simply send a new image to copy on it or a new microSD card?

It does but I have to go with their call which was to send the unit back to them for diagnosis. Maybe it is a hardware problem.

 

[John Kenny]

And where is that floating ground in your pre-amp John that is connected to the DAC? There isn't one, right? The audio precision acts just like your pre-amp would. If a ground loop is created in the ifi iPower and microRendu setup, you would have one just the same with your pre-amp. Ergo, I am measuring what real systems work like, not a hypothetical one you are making up. We care about system performance, not component. That is what generates sound.

Unbalanced connections are the most prevalent interconnect in audio. You seem to be thinking no one should measure them as such. Total confusion.

When you purport to measure something do you use a device designed to emulate your preamplifier or something much more sensitive & accurate?

No. you are not "measuring what real systems work like, not a hypothetical one you are making up." I'm not making up a hypothetical system - I don't know any preamplifiers that have another USB connection to PC as well as indirect RCA connection through a DAC also connected to the same PC

Again, just like your audio system. Every audio component has its own power supply and independent system. My laptop and AP also have two different power supplies, yet no "ground loop" was generated. A perfectly working system was broken with insertion of microRendu and iFi iPower.

You either don't understand or willfully miss the details of your two configurations. Is the ONLY difference between diagram 1 & diagram 2 the insertion of microRendu and iFi iPower? No, it isn't. How many other devices are inserted in the loop & how many are plugged into the mains? Without being scrupulous about ground noise injection you have no basis on which to point the finger at the uRendu or iFi iPower as the culprit - I consider this a rush to judgement. What it appears to me is that you have setup a ground loop & are seeing the consequences of this in your measurements

Why it was broken, ground loop or otherwise, is something for them to investigate and fix. If they cannot fix it and as a result say that additional means are created for ground loops to develop then this is a big cautionary note for users. Adding more moving parts to fix what is not broken is not a good idea.

Again, you are building a strawman argument here without presenting sufficiently rigorous measurements to justify your premise

What do you have in your audio system just the same? None I imagine would be your answer. You really have no argument here John. It is not like you have even shown to have been a ground loop here. In identical situation, two different power supplies had no issues with microRendu and my measurement system.

I am measuring the output of the DAC just like when it was directly connected to my laptop, "ground loops and all." As I said, you are seriously confused about audio measurements of unbalanced systems. Show me a single review of unbalanced connections in Stereo Review where JA used isolation. You won't find any.

Please, any basic text on measurements will warn about the introduction of common mode noise when using SE connections. Here's a tech note on noise using a laptop with AP - note the grounding! If you want more technical info - see these TI guidelines for measurements' Look under "Measurement Pitfalls"

You are also overly focused on the iFi issue. This product claims to lower noise floor. How come noise floor was not reduced under any condition? Do you have any measurements that show noise floor is lowered?

What you don't seem to comprehend is that if you have a ground noise issue, you will not see a reduction of system noise with any device - there could well be system noise reduction happening but the ground noise masks it & the reduction won't be measurable. So I'm not overly focussed on iFi, I'm focussed on your measurement setup & it's potential issues. Unless the configuration is rigorously audited then the accuracy of your measurements remain an unknown.

Sure, most here want to accept the measurements without question & make declarations about the uRendu (& iFi iPower) but if this forum is really putting itself forward as a bastion for audio science then there should be more than me looking into the details of the measurements, it's setup & possible issues.[/quote]

 

[Purité Audio]

I am sure you will be absolutely scrupulous when you make your measurements John, when can we expect them?
Keith