I'm Not Gonna Tell How Great My MicroRendu plus Sonore Signature Power Supply Sounds!
- Thread starter Steve Bruzonsky
- Start date
But alas is there any published body of work behind the Rendu's development?
Well, first off, the assertions about him having no measurement equipment is seen for what it is!!
Now the reason for why there are no measurements for microRendo (or Regen) - I take it that's what you mean? It's because there are no current measurements that are useful in showing what these devices do - Swenson is developing test equipment which he is hoping will show some correlation or as Swenson says
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Regardless of what you think about Amir, the lack of a technical counterpoint looks weak. That being said, if Steve and others are happy, so be it.
Where the fault-line shows between subjectivists & objectivists is exactly demonstrated in your statement & my previous remarks!
Audio devices have reached a level of refinement where mostly the gross issues have been dealt with (although this could be argued) - the gross issues (the first order issues) of frequency & amplitude that are revealed by stock measurements. What we are seeing more & more, are devices that are addressing second & third order issues. In other words, like the layers of an onion, as one layer of distortion is dealt with, the underlying layer can now be revealed & addressed.
The problem with these deeper layers of issues is that we do not know exactly what the issue is so that we can design a measurement to demonstrate it. The only means of assessing these issues is by auditory perception. But auditory perception doesn't tell us exactly where to look either - hearing a more realistic sound, doesn't give us a clue where we should focus measurements to find what is different. This is at the cutting edge of audio playback where there are no standard measurements. Asking someone to produce standard measurements to "prove" this is like the old logical fallacy "Have you stopped beating your wife yet"
Some known audio designers recognise & are actively working in this area such as Rob Watts, John Westlake & I would number John Swenson among these based on his past replies & the text I quoted above about him developing some testing equipment which he hopes will allow him to tease out answers to some of the issues that are on this fault-line.
My premise is that the answer will be found in noise floor modulation & how this affects our auditory perception. This is when there is a varying noise floor created by the playback equipment (usually the digital equipment) that fluctuates in some correlation with the dynamic signal that is being handled. There are good psychoacoustic reasons why this should be the first area to investigate & tease out. This is an area that currently escapes standard measurements & as I pointed out to Amir, measuring the static noise floor is a totally different thing. So producing such a static measurement & declaring that the device has no effect is, to me, seen all too often in objectivists - an arrogance that lies at the heart of the obj-subj rift - their belief that stock measurements show everything about an audio device (not that you would get them to explicitly state this but it is seen in their posts) & hence challenging others to produce counter measurements. On the other hand many people listen to these devices & hear an improvement in what they hear - which further underlines the disconnect between these measurements & auditory perception, so the rift is widened as reality is being denied.
If by "lack of technical counterpoint" you mean, lack of measurements then the above should answer that.
If you mean lack of argument then reading what John Swenson has said & informing oneself of the issues (as I outlined above) should not require the need for counter argument - it's all already out there
I'm not sure what you mean by "if Steve & others are happy"?
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We have a similar situation for 99% of the measurements taken in electronic audio equipment - the measurements are very useful and needed to access electrical performance and for development, but we are unable to establish firm correlations with subjective sound quality, particularly because the systems being used are all very different.
Unfortunately people risk using measurements in an abusive sense when looking only at the iceberg tip, ignoring the whole performance.
I routinely carry measurements on my equipment to access it - particularly with tube equipment, when looking for ground loops or setting a cartridge. But I do not grade my equipment using them! And any speaker entering and leaving my listening room is always measured - I have detected a few driver faults on arrival!
John,
Why do you think that this type of noise is created by playback and not by recording?
Yes, you are right - I suspect it might be an issue in both recording & playback but my focus, for the moment, is on audio playback, for a number of reasons.
One of which is that this is the area where the issue is showing itself first & is probably the easiest to get to grips with. I know Rob Watts claims that ADCs suffer from noise modulation as much as DACs & this is one of the reasons why care & cleverness with measurements is needed - he claims the APX55 is the first device that is capable of measuring noise floor modulation although I haven't seen any results from him yet.
I believe it's easier to experience this in playback rather than recording - as Fas42 has described - when volume is turned up & the sound gets shouty rather than just just louder.
I've also experienced what I believe is the same phenomena at other than higher volumes & it is perceived as more realism. This perception of realism comes from the attack part of the signal being free of this noise modulation. Another side effect of this is that soundstage seems to be better delineated because the attack is perceived as more defined.
An interesting recent AES paper seems to tangentially address this although I haven't been able to read it
Agree
The usual words of wisdom is that "the map is not the territory" but I would go even further & say that a map with details missing is very much a misleading guide to the territory.
The problem is that we don't yet know how to fill in these details & I have a lowly regard for the hypocrisy of people that use such measurements as a form of abuse, particularly using the science moniker.
It may be because I was schooled by "religious" teachers & I saw the hypocrisy of the "charity" that they dished out - all in the name of the religion they believed in.
I agree, there's a new form of trolling, the Science Troll: asks for 'science'-based evidence, but makes a total farce of real science, things like the DUT being chewed by the house dog, obvious mis-measurements, people not being schooled in Science asking for scientific proof, etc...
And without delving in the religious but merely spiritual and logical, I dare think that in this day and age, tables within the temples would be overturned as well...
Both of these examples are a form of corruption of the original.
While I enjoy philosophy (it fills 99.8% of forum pages and what audiophile doesn't like the sound of his own voice....), it is not really apropos in this situation. Engineer/manufacturer claims his gizmo "lowers the noise floor." Measurements are made by another engineer (former midlevel management at Microsoft) contradicting this claim. No counterpoint is provided despite reams of pontificating in response to said measurements.
From an intuitive, layman's standpoint, despite being a dedicated audio box, its diminutive size appears to make it vulnerable to "noise." Its sole selling point is size and convenience. Like the tiny house movement, being small does not make it intrinsically better than a normal sized house.
What we really need are dacs that are impervious to source. That is where more engineering energy should be spent.
I think you are just maybe misunderstanding the process, or being mislead by the so called measurements. What makes one think that size would have a relation to noise?
IMO Selling point is it sounds good end of story. Now size matters is talking sonics???
I think you are just maybe misunderstanding the process, or being mislead by the so called measurements. What makes one think that size would have a relation to noise?
IMO Selling point is it sounds good end of story. Now size matters is talking sonics???
Not really. Altered performance due to back leakage from a SMPS that otherwise "appears" to be low noise in alternative settings (according to the manufacturer) is odd particularly when they are recommended to be used together.
All this aside, it would be interesting (and even "scientific") to have Amir or some other tool with DIY propensities measure a standard puter with different PSs and to performed blinded listening tests to see if his kids or the local audio society could hear the difference.
Is there any evidence that this claim has been made?
As an engineer myself if I was claiming such I'd be sure to back it up with a measurement which demonstrates a lowered noise floor.
I appreciate your remarks about the technical info I gave but if you don't understand then there's no reason to imply that it is philosophy & I like the sound of my own voice
Yes, it is apropos to the situation. No, the designer, John Swenson, doesn't claim this & you are now repeating Amir's misinformation as if it was Swenson's claim - it's Amir's misunderstanding/misinterpretation which he then set about measuring.
What Swenson said was
"The microRendu produces a very clean USB signal to the DAC, which seems to produce lower noise levels in the DAC. The exact mechanism for this is not well understood at this time. The lower noise in the DAC allows the DAC circuit to operate at its peak performance. "
Note the words in bold "SEEMS to produce lower noise levels in the DAC". Does this mean that it lowers the noise floor? No, it doesn't. Why would an engineer of Swenson's calibre say this & then go on to say "The exact mechanism for this is not well understood at this time" if it was just static noise floor that he was talking about? Static noise floor is easy to measure & it's certainly not a mystery or "not well understood at this time" Swenson is talking about the perception of the sound. If your read any of Swenson's statements about the microRendu or Regen, you would realise this. Why would he be intending to develop the test equipment in his above quote if he could easily measure this static noise floor? Do you think he is telling lies & just trying to sell devices? If there was any confusion about this (as Amir has stated he has) then I would expect the appropriate thing to do was to check with the designer before intending to do measurements of the microRendu.
Note the words in bold "SEEMS to produce lower noise levels in the DAC". Does this mean that it lowers the noise floor? No, it doesn't. Why would an engineer of Swenson's calibre say this & then go on to say "The exact mechanism for this is not well understood at this time" if it was just static noise floor that he was talking about? Static noise floor is easy to measure & it's certainly not a mystery or "not well understood at this time" Swenson is talking about the perception of the sound. If your read any of Swenson's statements about the microRendu or Regen, you would realise this. Why would he be intending to develop the test equipment in his above quote if he could easily measure this static noise floor? Do you think he is telling lies & just trying to sell devices? If there was any confusion about this (as Amir has stated he has) then I would expect the appropriate thing to do was to check with the designer before intending to do measurements of the microRendu.
Or even more cogent when Swenson states
"What seems to be happening is that the USB hardware in the DAC is generating noise on power and ground planes which causes increased jitter from the local oscillator, AND causes the DAC chip to receive that clock with additional jitter. That noise can also make its way into the DAC chip directly so it is a combination of jitter and good old fashioned noise.
The fun part is that this P/G noise seems to be modified by the signal integrity of the incoming USB signal. When the USB signal is generated by a circuit using a lower phase noise clock we get a change in the noise. Exactly what is causing this is unknown. I don't have the right tools to do an in depth analysis of this chain from USB clock to P/G noise to DAC clock phase noise. It would take several hundred thousand dollars worth of test equipment to track this all down. I can't afford that!
On the surface it would seem that all you need to do to get around this is to have isolation between the P/G domains of the USB circuitry and the DAC. This helps some, but does not seem to get rid of the issue. As far as I can tell the issue is that the P/G noise is adding jitter to the signals crossing the barrier and when those signals get into the DAC domain the jitter on those signals is still there. Just the signals going through any chips will create noise in the DAC domain which is correlated with the jitter in the USB hardware domain. This happens in the isolator chip and inside the reclocking flop itself.
Completely getting rid of this seems to be a very difficult task.
So yes your statement that the isolation is not perfect is in fact the case, but making it perfect is not trivial. Just using an off the shelf isolator chip and a flip-flop does not cut it.
The fun part is that this P/G noise seems to be modified by the signal integrity of the incoming USB signal. When the USB signal is generated by a circuit using a lower phase noise clock we get a change in the noise. Exactly what is causing this is unknown. I don't have the right tools to do an in depth analysis of this chain from USB clock to P/G noise to DAC clock phase noise. It would take several hundred thousand dollars worth of test equipment to track this all down. I can't afford that!
On the surface it would seem that all you need to do to get around this is to have isolation between the P/G domains of the USB circuitry and the DAC. This helps some, but does not seem to get rid of the issue. As far as I can tell the issue is that the P/G noise is adding jitter to the signals crossing the barrier and when those signals get into the DAC domain the jitter on those signals is still there. Just the signals going through any chips will create noise in the DAC domain which is correlated with the jitter in the USB hardware domain. This happens in the isolator chip and inside the reclocking flop itself.
Completely getting rid of this seems to be a very difficult task.
So yes your statement that the isolation is not perfect is in fact the case, but making it perfect is not trivial. Just using an off the shelf isolator chip and a flip-flop does not cut it.
Again, if you don't understand this then ask questions rather than snide remarks
Again, let me correct this - he sets out to measure what isn't claimed & then he, you & others start to accuse Swenson of not producing counter-measurements. As I said already it's a logical fallacy - let me ask you this - can you show us evidence that you don't beat your wife?. If you read what I posted already the measurements to demonstrate what the MicroRendu & Regen are doing to the signal waveform need to be developed - this is the situation we have with these devices & others."
Why not ask Amir to produce measurements from the analogue out of a DAC which shows the audible improvement of the Intona on a USB DAC to see how his measurements stack up?
Sure, I can't argue - that is a layman's perspective. Can I ask you - have you listened to a microRendu or Regen?
Of course that's what we need but this is not an easy problem to completely solve - partial answers are emerging & more will probably materialise along with understandings of the underlying mechanisms of what is happening
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I don't know if Amir will appreciate you calling him a "tool"?
As a layman, what do you understand by " back leakage from a SMPS"?
Indeed!! I make exactly this case - noise floor as Amir has measured is not a difficult measurement & evaluating Swenson's engineering chops, I find it unbelievable to contend that "lowers the noise floor" is Swenson's claim.
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That's exactly what I see happening here.
Yet, it's funny how many can't seem to see through all this.
http://www.microrendu.sonore.us
This point has been splashed around in multiple forums including Computeraudiophile, etc, etc.
I don't know if Amir will appreciate you calling him a "tool"?
As a layman, what do you understand by " back leakage from a SMPS"?
"Tool" is US collegiate slang for engineer.
I have seen "back leakage" bandied about in regards to SMPS switching frequency noise that leaches back onto the mains due to a cheapo supply with an unfiltered output. The Blizzinator told me his Japanese supplies and better designs are relatively impervious to this, etc, etc. Educate me if you feel you must. That is my faux interpretation.
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