Thanks for the link (wish they would have adopted a more straightforward style, though - the many puns and pictures are a little tedious to go through, IMO).
One thing I do not quite understand, is that the test was performed with different power supplies: the ifi, a lab power supply, and a power supply from sbooster. The last two showed good measurements. So if there were a ground loop, would it not be present with all three?
Also, as a side note, I seem to remember that Swenson had also challenged ifiâs claims on the CA forum a while back (when the PS first came out, and a long time before you chose to package it with the RenduâŠ).
Hi guys. Was out on a mini-vacation. Was pleased to see I was not being sanctioned for posting here. Much appreciated.
On iFi response, I too was disappointed to see all the energy put in comics aspect of their write-up, yet they did not try to contact me and learn more about my tests and my background since they are questioning both. As best as I can tell, they seem to think I have been measuring their power supply which I have NOT done. I am testing Sonore microRendu and ifi iPower as a packaged system. I put in a much more detailed explanation to cut through the confusion here: Measurements of Sonore microRendu Streamer | Page 22 | Audio Science Review (ASR) Forum
I hope they contact me and produce measurements to show how the above combination is performant. Saying there is a ground loop when two out three components are theirs (power supply and DAC), tested just like any customer would in an unbalanced system, doesnât seem like a healthy direction to me.
When doing tests or any other type of analysis there has to be some type of baseline or calibration, some way to understand that the testing system or the methodology actually has any merit.
A simple example is a speed radar gun used by the police department. This has to be calibrated and certified in order to ensure that a displayed speed when brought to court is actually legally useful. Without this, any stops made with this device cannot be legally used in a proceeding.
Moving on to your [Moderated] testing, how do we know that this test can show any useful differences that can be directly related to sound. You keep insisting that your test can determine fidelity and that the two devices you have tested so far which curiously are from the same designer either do not degrade or actually can harm sound quality.
Can you please show us that your methodology can actually be directly related to sound quality, as this is what you are trying to tell us. Without this what you are doing is pretty meaningless.
[Moderated]
You have to provide some calibration, a baseline to show reliability of your methodology.
[Moderated]
Please seriously consider this, as at this moment everything that you post shows little or nothing in regard to sound quality. And at the end of the day what we are doing here is listening to music and not looking at pictures of meaningless test tones.
Alex C has no direct commerical interest in the mR. He doesnât make money from it, it isnât his product.
He is about to market a power supply that among other uses, will be marketed as an upscale PS for the mR.
So actually, bad measurements for the iFi are good for his product.
Alex does work with John S. as a designer - he also designed the mR for Sonore. The mR has a USB out that is similar to the Regen that John S. designed for Alexâs company. So you could say he has indirect interest in the mR having good measurements as it reflects on his product. Also, Amir made similar comments about the Regen itself.
iFi has already publicly stated and explained that they believe Amir doesnât know how to use his AP measuring equipment properly, and that they are about to post different measurements and show what the iFi power measurements look like when the measurements are done properly.
Lets see what happens when they publish.
My problem with the ASR thread is that after one set of botched measurements, the Amir fanboys there all accept Amirâs measurements as TRUTH. Iâm not rejecting them, but one set of measurements by one guy - who botched the measurements on first try - doesnât count as âproofâ to me. Iâd need confirmation from somewhere else in order to accept Amirâs measurements.
Really? In your tests you showed the iFi to be the source of added noise in the mR output.
The thread is full of your fanboys dissing the iFi and commenting how your tests prove it to be a âsnakeoilâ product bought by âaudiofoolsâ.
Why would iFi want to contact you about your tests? They also own an AP, and from reading your results they believe you donât know how to operate it properly for definitive results in audio testing - i.e., that you are getting âghostâ results from a lack of fulll knowledge of how to use the device.
I donât know whoâs right.
Theyâll publish their results and methodology, and the public can judge which results are more credible.
Make sure they are responding to the right set of issues. As I noted, from my read of their post, they appear to be thinking I am showing measurements of their power supply output which I am not. Another person did that test and they seem to think mine was the same. It was not at all.
You build goodwill. I was on their side of the fence for nearly 30 years, producing products that got reviewed. You always want to take the high-road, try to make a connection, see if there are real issues that need resolving, etc. It is just good form.
The best outcome here is one where both sides agree to what the facts are. Writing multi-part PDF docs without contacting me and confirming their assumptions simply is not the way to do it in my book. If you think as a consumer you are best served with this kind of back and forth, then I am not here to change your mind. Only speaking mine.
The testing I did took just a few hours and that included figuring things out that they donât have to now. By now, both manufacturers should have run their own version and post the results. As you say, that would speak volumes. We donât need long intros, comics, etc. Yet that is all we have after a week that has gone by.
Please read my response to them. What they say does not hold water at all. If you have questions, please ask. Donât go by their headline. They have not made any valid case against my methodology. It is what John Atkinson does day in and day out in his measurements in stereophile.
As far as the other test done on the iFi, both the guy who did it and iFi say it doesnât back up your results. You seemed previously to say the opposite. Whatâs the explanation, as far as you understand it.
Iâm closing this thread for the time being while moderators decide what to do with it.
Edit: Ok, Iâve decided to re-open the thread because there is an interesting audio related discussion buried underneath here.
I have moderated posts or parts of posts that do not comply with the Forum guidelines or which solely discuss such posts. Where I have edited material out of a post I have marked it [Moderated].
There may be a place for people to carry on arguments from other forums, or engage in personal ad hominem attacks, but it is not this place.
Edit2: Thanks @danny2 for clarifying Alex Câs position as regards the microRendu. Apologies to Alex for my assumption.
Thanks, Andrew. Difficult task for moderators as the debate seems to be quite personal; but I appreciate your efforts to keep discussions open and civil.
Craig
The problem with threads like these is not so much the measurements themselves (anyone is free to take them for whatever they think theyâre worth), but lies in the grandstanding that follows at various online outlets, the careless speculation on design choices, the demanding nature that manufacturers should respond or consult. After all â this is just a guy on the internet taking (poorly documented) measurements and posting on the internet about a guy taking (poorly documented) measurements. If this is the state of âAudio Scienceâ, then count me out.
What is troubling however is that this careless speculation is potentially damaging to great little companies coming up with innovative, sensibly priced solutions for the digital audio age and offering great consumer service. In no way they are under any obligation to respond to every other guy on the internet taking (poorly documented) measurements and posting on the internet about a guy taking (poorly documented) measurements.
I think iFiâs responses offer a well-needed perspective. At least they offered some insight and made me smile â which is more than can be said about the mess above.
Just for the record: I do not own nor intend to own any equipment from the companies mentioned above.
Ther personal aspects need to stop and I vote for aggressive moderation in this regard. This is a âseriousâ sudiophile/sonic discussion. There is a lot of snake oil sold in both the low-end and high-end market. I doubt there is a difference that can be heard with the Rendu in a system that costs less than $5K- 10K, but I am happy to be proved wrong.
iFi sums it up nicely: âmuch ado about nothingâ. Iâm just back from a long run and right now Iâm listening to some nice music using Roon through the microRendu. Pure bliss!
Iâm not using the iFi PSU (waiting for a nice Paul Hynes SR7EHD-MR4 and using a cheap Chinese EBay linear PSU in the mean time) but even if I were these measurements mean absolutely nothing to me. I question both the motives for and execution of them. Being as one-dimensional as they are, theyâre about as useful for determining the microRendu sound quality as a photograph of the device is.
PS: I was educated to become an EE but got into ICT instead as I found that more interesting. I used to be a lot like many here: âbits are bitsâ, denying anything else until I started trying some of the stuff other people experimented with. Bits are still bits but thereâs simply more to it, especially when it comes to the D to A conversion. Especially with the less than ideal (for audio) USB interface a lot comes down to high quality power supplies and clocks, proper isolation between different domains in power and ground planes to feed the DAC the cleanest signal possible. This all matters just as much for the DAC internal circuits as well. Of course Iâd like to have a DAC thatâs simply impervious to anything bad itâs fed but I donât think one exists yet, although some may come close.
I am too dumb to know if the above references are to me or not. In case it is, and I hate flashing my resume, I am be dumb but not an idiot on the Internet. This is part of my qualifications: Introductions anyone? | Audio Science Review (ASR) Forum
iFi talks about how they have had an Audio Precision Analyzer for 10 years. That would make it 2006. I bought our first Audio Precision Analyzer around year 1990 when I was working at Sony and I wanted to measure our computer designâs audio fidelity. Few people knew about the company as HP ruled the world then (now Agilent/Keysight).
The AP unit I now have is long in the tooth but it costs $25,000. I donât know anyone who buys and owns such a device and doesnât know how to operate it. I have written countless articles which have been published in major AV magazines and not one manufacturer has called to complain about the data.
None of this makes my data right. I could have made mistakes. But one dog that donât hunt is to assume I am some random blogger on the Internet. I am not. This is a hobby for me after retirement in the industry and I am fortunate enough to have the tools and experience to share what I discover.
And oh, it is not âscience.â It is simple qualification of design criteria. Sonore Says that their product does this:
"What makes the microRendu different from a typical computer music server is that itâs a purpose built audiophile device. The problem with computer music servers is that they all rely on mass produced motherboards designed for general purpose computing and are built to the lowest possible price point. The microRendu solves this problem by removing the consumer grade computer peripherals and optimizing power supplies where necessary. The microRendu has been specifically built for processing USB audio perfectly. You can also combine the microRendu with an audiophile grade linear power supply to achieve the lowest possible noise floor. "
I have not found any evidence of the device lowering noise floor. This is an objective claim that is trivially verified. It is what we use instrumentation for. My consumer grade computer is doing as well as it is yet it is mass market products.
I donât take any pleasure out of finding and reporting on what I do. I am simply on the consumer, not manufacturers. Products get reviewed all the time on Amazon. Why doesnât Amazon take them down if they are negative? Well, I asked them that question! When I was at Microsoft we made a major announcement with them that had a very short fuse. So I went there with our PR people to write and approve the press release right there. While PR people were working, I asked my counterpart executive at Amazon why they leave those negative reviews. And wouldnât they hurt sales? His answer stays in my mind to this day:
âWe are on the side of consumers, not manufacturers. We need to earn the trust of consumers.â
And that is what my goal and mission is now. If manufacturer makes statement that at technical level seem implausible, I use my own money to buy and test the product. I post the results and let folks have more visibility into them. I try to be as fair as I can as you see here where I went out of my way and tested the Sonore microRendu with my own lab power supply which generated better results than iFi. I didnât have to do that if all I aimed was to hurt them. I like to troubleshoot and get to the core of the problem and report on that.
Well, I am an EE. And no, I do not believe in bits being bits. Written a bunch of articles on that showing with objective measurements how that is not so. See the last two links I provided where I tested different digital interfaces and yet, the analog output of DAC varied.
It is in that landscape where I am cautious about the statements made here. High performance USB DACs must, must by definition be immune to noise on that link. If I wanted a USB DAC that was not, I would buy an ebay $20 product. When I spend thousands of dollars on a USB DAC, I expect to not even wink no matter what is going on on the USB bus. The bus must be used in async manner with galvanic isolation. Once there, what on earth is this device is going to do extra???
Besides being an EE, I managed the audio signal processing and compression group at Microsoft. I created, conducted and analyzed literally thousands of audio listening tests. Without controls, vast majority of ad-hoc tests such as what you mention generate faulty results. They just do. I love to have my listening test results be as valid as the next guy. But despite proving that my training in hearing audio compression sets me aside from many others (see the link Bob provided to my high-resolution audio listening tests), I have lost track of how many times there was no difference in sound waves hitting my ears yet I thought there was night and day difference. If you want others to accept that bits are not bits, then for your part you need to accept that your listening tests very well may be faulty. Certainly tons more faulty than objective measurements I am sharing.
I donât make these rules . It is just the way to science/engineering of audio works.
This exactly what is bothering me: big words, broad asides, little substance.
Let me just state that I hope this thread will either run its course or finds a way to stay on subject. Speaking of which: as the subject itself is of little interest to me, Iâll gently remove myself from the conversation here.
Was out on a mini-vacation. Was pleased to see I was not being sanctioned for posting here. Much appreciated.
