Measurements of Sonore microRendu Streamer

[dallasjustice]

Since all human brains are made with these defects standard in the factory, the intention or experience isn't important to me.

I can't tell if Chris Connaker is a huge shill (after all, he quit is day job to run Computer Audiophile...gotta keep those ads coming), or just an unadulterated placebophile of the nth degree.

 

[Sal1950]

There is such a thing as integrity.
When we attempt to create or distribute information for the enlightenment of others, we owe it to everyone including ourselves to ensure such is accurate.

 

[watchnerd]

And this is your first mistake, Amir - what Swenson is saying is that the output from the DAC is perceived as lower in noise - in other words with music signals the perception is that everything emerges from a quieter background.

[emphasis added by me]

I can measure the noise floor on a recording using a spectrum analyzer. This includes recordings I have personally made. Noise floor on playback will be the worst element in the chain, either of the recording itself or the combined elements in the playback chain.

One of the microphones I use is a Neumann TLM 103, which has the following stats:

Equivalent noise level, CCIR1): 17.5 dB
Equivalent noise level, A-weighted1): 7 dB-A
Signal-to-noise ratio, CCIR1) (rel. 94 dB SPL): 76.5 dB
Signal-to-noise ratio, A-weighted1) (rel. 94 dB SPL): 87 dB
Maximum SPL for THD 0.5%2): 138 dB

The microphone's self-noise in this case is 7 dBA (quite good). This gets added to the ambient acoustic noise of the recording venue, which in the case of a local jazz venue is about 40 dbA, about as quiet as a library. This gives the following noise floor for the recording:

7 dBA (microphone self noise) + 40 dbA (venue) = 47 dBA
Peak SPL at the TLM 103 during recording (in my last real life example) = 92 dBA
Raw (uncompressed) dynamic range at the microphone = 92dBA - 47dBA = 45 dBA

This puts the recording noise floor WAAAY above the noise floor of digital silence on a 24bit recording (-144 dB), WAAAY above the jitter floor of most good DACs (> -100 dBFS), and WAAAY above the noise floor of other items in a quality electronics playback chain (> 100dBA SNR).

So given all this, please explain how this device will make it so that "everything emerges from a quieter background" when the weak link the quietness chain is the recording itself?

 

[RayDunzl]

7 dBA (microphone self noise) + 40 dbA (venue) = 47 dBA

Are you sure?

7dB + 40dB = 40.002dB

 

[watchnerd]

Are you sure?

7dB + 40dB = 40.002dB

Yep, you're right. I forgot to use log math.

But apparently I was framing an argument against a dead man, so it's all rather moot.

 

[fas42]

So given all this, please explain how this device will make it so that "everything emerges from a quieter background" when the weak link the quietness chain is the recording itself?

Because it trades on the human ability to filter out noise it's not interested in - luckily, the ear/brain is not a Radio Shack measuring device; in fact, it's immensely clever at ignoring what it considers irrelevant at the time - this is the "cocktail party effect", which a lot of research has gone into - amidst a hubbub of competing prattling, you can tune into the one bit that concerns you, and follow it.

Better quality audio does the same thing - it becomes so much easier to follow the strand that interests you, the musical event that the recording captured at some level of quality. When you can play a 1912 recording at maximum volume, and "hear" the singers emoting, as if they're in the room with you, even with the crackling and dreadful limitations of that medium - then it becomes understandable what's possible ...

 

[watchnerd]

Because it trades on the human ability to filter out noise it's not interested in - luckily, the ear/brain is not a Radio Shack measuring device; in fact, it's immensely clever at ignoring what it considers irrelevant at the time - this is the "cocktail party effect", which a lot of research has gone into - amidst a hubbub of competing prattling, you can tune into the one bit that concerns you, and follow it.

Better quality audio does the same thing - it becomes so much easier to follow the strand that interests you, the musical event that the recording captured at some level of quality. When you can play a 1912 recording at maximum volume, and "hear" the singers emoting, as if they're in the room with you, even with the crackling and dreadful limitations of that medium - then it becomes understandable what's possible ...

@fas42 have you used this device?

 

[fas42]

This device?

 

[watchnerd]

This device?

The Sonore Micro Rendu -- about which my comment was made.

 

[fas42]

No ... but any piece of audio equipment which allows one to discard, subjectively, the accompanying noise more effectively is one up, in the game. No piece of equipment is "magic" - all it can contribute is lessening the levels of artifacts which annoy one, while listening.

 

[amirm]

No ... but any piece of audio equipment which allows one to discard, subjectively, the accompanying noise more effectively is one up, in the game.

How do you know it does that?

 

[fas42]

From experience ... my process of tweaking has always been to improve aspects that introduce low level noise, distortion into the final sound. As I work my way through the "usual suspects" the subjective quality improves, to the point where I get my "convincing" sound - I've refined this technique over the years, and know one can get to the point where one only "hears" the recording; the irritating anomalies are no longer apparent.

 

[watchnerd]

From experience ... my process of tweaking has always been to improve aspects that introduce low level noise, distortion into the final sound. As I work my way through the "usual suspects" the subjective quality improves, to the point where I get my "convincing" sound - I've refined this technique over the years, and know one can get to the point where one only "hears" the recording; the irritating anomalies are no longer apparent.

Yeah, but we're not talking about your process.

We're talking about specific claims made by the product manufacturer, and its advocates, about this device.

If you're not a maker or user of it, I don't think you have a dog in the fight.

 

[amirm]

From experience ... my process of tweaking has always been to improve aspects that introduce low level noise, distortion into the final sound. As I work my way through the "usual suspects" the subjective quality improves, to the point where I get my "convincing" sound - I've refined this technique over the years, and know one can get to the point where one only "hears" the recording; the irritating anomalies are no longer apparent.

Keep in mind that the Sonore MicroRendu is not a tweak. It adds another processor and power supply into the equation. So you cannot assume that the only direction the performance can go, is up.

 

[fas42]

No, I certainly can't assume that it will automatically make the sound "better". Feedback from users will guide one though - if there are reviews, or user experiences where the subjective response is a negative one, I would be happy to be pointed to them.

 

[skypickle]

amir, thank you for your measurements. I wonder though if it is possible to measure noise coming out of the usb port. I realize that the power supply is the object of focus as the sure of noise, but the end product is the usb signal. Is it possible to look at the noise at the level of the usb port? If I wanted to make these measurements, what is the minimum setup I would need (so I don't have to keep pestering you)?

 

[skypickle]

But so does a Raspberry Pi @ $50

Has there been a comparison of these two device (microrendu and RPi) in jitter and noise at the usb port?

 

[March Audio]

Has there been a comparison of these two device (microrendu and RPi) in jitter and noise at the usb port?

Not that I know of, however the first question is what and why are you worried about on the USB port?

Noise from a PC (or other computing device, Pi or whatever) can be carried along in the ground connection, plus I suppose RF noise on the data/PSU lines. This why I use an Intona galvanic isolator.

http://intona.eu/en/products

Not that I have ever had a problem, or heard a difference, but it will eliminate the potential for that problem.

Jitter. This is a bit of a red herring. The USB clock isnt the DAC word clock. The data is asynchronous, buffered and clocked out to the DAC chip with a local clock.

This quote from intona is very interesting.

http://intona.eu/en/answer/1236
http://intona.eu/en/answer/popular


My attitude is, use Roon with a Pi, the Intona and problem solved!

Unlike some other usb "conditioners" that could be mentioned, Intona actually know what they are doing and have the measurement kit to test and prove it.

 

[amirm]

amir, thank you for your measurements. I wonder though if it is possible to measure noise coming out of the usb port. I realize that the power supply is the object of focus as the sure of noise, but the end product is the usb signal. Is it possible to look at the noise at the level of the usb port? If I wanted to make these measurements, what is the minimum setup I would need (so I don't have to keep pestering you)?

Unfortunately USB is a very high-speed serial bus. To make sure the instrument itself doesn't get in the way, it requires an oscilloscope running at 4+ Gigahertz. Such scopes exist but with all the bits and bytes to go with them, you are looking at $50K to $100K in instrumentation! The fastest scope I have is 500 Mhz so I am not there.

I suspect the above is the reason microRendu folks themselves have not made and reported on such measurements.

There is a cheaper path which is to buy obsolete oscilloscopes that do go up to these speeds. They are massive boxes, potentially very hard to repair and use. I have been looking into this but so far have not found a unit that still was not too expensive to use. And there is also the justification of buying such a gear just to make USB measurements when the final goal really, is measuring the DAC and that I can do as I have reported here.

 

[March Audio]

Unfortunately USB is a very high-speed serial bus. To make sure the instrument itself doesn't get in the way, it requires an oscilloscope running at 4+ Gigahertz. Such scopes exist but with all the bits and bytes to go with them, you are looking at $50K to $100K in instrumentation! The fastest scope I have is 500 Mhz so I am not there.

I suspect the above is the reason microRendu folks themselves have not made and reported on such measurements.

There is a cheaper path which is to buy obsolete oscilloscopes that do go up to these speeds. They are massive boxes, potentially very hard to repair and use. I have been looking into this but so far have not found a unit that still was not too expensive to use. And there is also the justification of buying such a gear just to make USB measurements when the final goal really, is measuring the DAC and that I can do as I have reported here.

Dont forget the fast differential probe!