I'm Not Gonna Tell How Great My MicroRendu plus Sonore Signature Power Supply Sounds!

Elberoth · Jun 23, 2016

jkeny said:
I suspect that Amir has some grounding issues in his measurements setup & these are showing up in hi measurements when the right conditions arise. His own measurements showing 60Hz & related harmonic spikes should immediately signal such an issue was at play in the measurement system. The 8KHz spikes in his Regen tests were also a sign that he has some grounding issues, I believe.

Unfortunately, he seems reluctant to investigate this possibility instead he blames other devices for what is his system issue.

As to whether the microRendu should be immune to passing through such ground noise issues, I would suggest that devices are designed to work in normal setups - setups that have grounding issues should be fixed & normalised, it's not the job of the audio device to do this unless it's a specific design goal of the device

I'm not sure those are just grounding issues. John Westlake - who is a seasoned audio designer - also noted 8kHz related USB noise when he tested the Regen. He also showed how this noise can be easily cancelled out, with just 3 modifications.

From his post on PFM:

Regen PSU noise measured with a "nothing special" lab linear PSU - note the 8KHz related USB noise currents on the PSU rail.

I added 3 modifications to the Regen PCB to reduce the USB packet noise, otherwise the same as above with the linear PSU:

Original post:
http://www.pinkfishmedia.net/forum/showpost.php?p=2689811&postcount=192

That is why I said I would be surprised If the problem is still present on the microRednu. But I'm not an engineer, so I might have read it all wrong. Plus, John Westlake is working on a competing product, so has a stake here as well ...

jkeny · Jun 23, 2016

Yea, I saw those measurements, Adam & I believe they were also done with single ended set-ups (both audio system & measurement system).
AFAIR, BE718 also did measurements & didn't find these 8KHz spikes - his playback system is balanced all through - was his measurement system also using balanced probes (as John S suggested?)
The added resistors in the ground plane of the Regen were the cause of the 8KHz USB packet spikes showing up on the measurements but these only showed up in single-ended & not balanced

It's difficult to speculate on all of this as neither Amir, nor John Westlake gave us enough information about their measurement systems to be able to come to any firm conclusions about this but everything points towards a ground issue, IMO.

Something I would investigate more fully before declaring a device results "degradation is as much as 30 db" & adopting the attitude to prove him wrong with measurements

To my mind he rushed to judgement with the Regen, declaring the spikes as additional jitter before I corrected him - he similarly rushed to judgement about the uRendu (8dB higher amplitude on DAC output - really?).
It does paint a picture of a less than objective approach to this

Elberoth · Jun 23, 2016

Yes, I agree with you 100%. It is all possible.

wisnon · Jun 23, 2016

The original Regen Green did not have the extra resistors. They were added due to subjective SQ enhancement potential.

jkeny · Jun 23, 2016

wisnon said:
The original Regen Green did not have the extra resistors. They were added due to subjective SQ enhancement potential.

Yes, but what's your point?

wisnon · Jun 23, 2016

Maybe if Amir/Westlake tested that, they would have not had the same result they found objectionable?

jkeny · Jun 23, 2016

wisnon said:
Maybe if Amir/Westlake tested that, they would have not had the same result they found objectionable?

You mean they would not have the 8KHz spikes on the graphs?

Yes, but I would expect Amir's results to then be framed in exactly the same way as we see his uRendu measurement results framed i.e. SMPS introduces degradation & a better quality PS shows that the Regen does nothing to improve analogue DAC output, no?

The reason I'm skeptical with his approach is that I have experimented with the Regen & with addressing the various PS areas within a PC & my experience reflects that of others - they both can make an audible improvement.

wisnon · Jun 23, 2016

Fair enough.

jkeny · Jun 23, 2016

wisnon said:
Fair enough.

I see Mivera has suggested on ASR that he & Amir do measurements on the exact same device (he using his rented APX-555 & Amir using his older AP device?) & post results - this might be useful as some sort of "calibration" of the measurements but I predict it won't happen.
Sorry for my skepticism but isn't skepticism considered a healthy attitude according to our objectivist friends?

Antoine · Jun 25, 2016

IFi is responding to these ASR measurements of the iFi(/microrendu). They might prove it's (a) ground loop(s) that messed up these measurements.

"Much Ado About Nothing". It will be a four parts article, first two have been published as of now:
http://www.computeraudiophile.com/f...easuring-ipower-much-ado-about-nothing-28982/

Geardaddy · Jun 25, 2016

Antoine said:
IFi is responding to these ASR measurements of the iFi(/microrendu). They might prove it's (a) ground loop(s) that messed up these measurements.

"Much Ado About Nothing". It will be a four parts article, first two have been published as of now:
http://www.computeraudiophile.com/f...easuring-ipower-much-ado-about-nothing-28982/

Outstanding.....what will the men of science say now? I will repost the link on ASR....

jkeny · Jun 25, 2016

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.

YashN · Jun 25, 2016

So apparently, the Blizz, under his moniker of Mivera Audio has his new device out.

It looks good.

Has anyone heard it?

Geardaddy · Jun 25, 2016

YashN said:
So apparently, the Blizz, under his moniker of Mivera Audio has his new device out.

It looks good.

Has anyone heard it?

I am getting one soon.

wisnon · Jun 27, 2016

YashN said:
So apparently, the Blizz, under his moniker of Mivera Audio has his new device out.

It looks good.

Has anyone heard it?

Yes, it does seem good. I quizzed him about it and it seems solid.

GearDaddy, please let us know ASAP.

jkeny · Jun 27, 2016

jkeny said:
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.

It seems I was wrong - the Audio Precision model Amir has (model 2700) does have a USB connection but he states he is using the USB-APIB bridge as the connection between laptop & AP - don't know why?

jkeny · Jun 27, 2016

Oh dear, Amir has banned me

Too many of his flaws & the general forum arrogance & attitude being exposed to the general public
Let's see if they now clean up the thread to sanitise the ridicule, insults & bad language directed at me in their posts & remove some of my posts too?

NorthStar · Jun 27, 2016

jkeny said:
Oh dear, Amir has banned me
Too many of his flaws & the general forum arrogance & attitude being exposed to the general public
Let's see if they now clean up the thread to sanitise the ridicule, insults & bad language directed at me in their posts & remove some of my posts too?

Lol, must be just temporary John. Hang in there.

...Irish folks have green blood?

Yeah, they just don't know that "rich heritage" that came to America back then.

Hey, we live in a universal world, but not everyone is aware of all the various "voltages".

jkeny · Jun 27, 2016

NorthStar said:
Lol, must be just temporary John. Hang in there. ...Irish folks have green blood? Yeah, they just don't know that "rich heritage" that came to America back then.

Hey, we live in a universal world, but not everyone is aware of all the various "voltages".

Hehe, your optimism is naive, I'm afraid - it's a permanent ban - they just don't accept peer review or alternative viewpoints/opinions.
I have to say that thread was fun though - pity they don't allow open discussions?

Geardaddy · Jun 27, 2016

jkeny said:
Oh dear, Amir has banned me
Too many of his flaws & the general forum arrogance & attitude being exposed to the general public
Let's see if they now clean up the thread to sanitise the ridicule, insults & bad language directed at me in their posts & remove some of my posts too?

I thought you'd already been banned?

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