What is the Argument for USB DACs and Streaming via USB?

[plissken]

He's as lame and trollish as Amir.

 

Let me guess... If I go into the thread and find the other EE's that confirmed Amir's measurements you'll say they are lame also?

 

It's an interesting debate style.

[YashN]

Let me guess... If I go into the thread and find the other EE's that confirmed Amir's measurements you'll say they are lame also?

 

It's an interesting debate style.

 

Also interesting: you can't name "4 EEs", and can't say whether you have Engineering credentials.

 

You belong to HA or Amir's forum. Have fun there with others like you.

 

What debate? You've already shown your own level of ignorance. You wouldn't be able to debate me if your life depended on it.

[sandyk]

Let me guess... If I go into the thread and find the other EE's that confirmed Amir's measurements you'll say they are lame also?

 

It's an interesting debate style.

 

What makes you clowns think that the measurements you have taken have any relevance to the improvements heard by so many CA members, and more than a few WBF members ? Did you even use anything better than the cheap Meanwell SMPS when the measurements were performed ?

Quite a few members are now reporting marked SQ improvements when using vastly improved power with the Regen, especially if the power is isolated from the AC mains supply, which the new LPS-1 and battery derived supplies provide .

 

If you love WBF so much, what the f**k are you doing here ?

Don't bother answering. It's called TROLLING !

[Jud]

Agreed. However, in the event that the DAC does not completely "take care of it", a device sold as a "filter" or improvement via an inline box ostensibly addressed at the issue of reducing noise, what do we have if it measurably increases noise insted?

 

I am still seriously disappointed that the measurements glibly promised over and over by both John and Alex never materialized. What does this say about their alleged genius and integrity? IMHO, they goofed and revealed themselves for what they are big time. No more of their promises and products for me.

 

The Meridian USB was working fine however. They implemented the USB interface properly. They implemented their interface according to Intel's standard. The Regen buggered the standard by adding a resistor to ground.

 

I write software for the credit card industry. One of the things we do is pass a string with token id and not the actual card data. It's considered a best practice so you are PCI compliant. It would never occur to me to write additional handling to detect a mask of XXXX XXXX XXXX XXXX because some other idiot at a processing gateway decided to use the card number in the clear as the token id value. That's not on me as the developer.

 

Why would Meridian, looking at Intel's implementation guide, and seeing how to implement rejection of ground noise think: Hey we need to do X, Y, or, Z because some idiot is going to introduce something that is totally out of spec?

 

Meridian did their job. It's not their job to secure their DAC from receiving 120VAC on the USB buss if we want to take your position and extrapolate it to, what I think we both agree, is a ridiculous conclusion.

 

Since we've gone to the extent of name calling and slagging of reputations, I think it's time for something that may be of interest.

 

This is from a Roon Labs Community thread about the microRendu ( https://community.roonlabs.com/t/microrendu-measurements-thread/11761/226 ), designed by "some idiot" named John Swenson, and incorporating that awful Regen circuitry that "bugger the standard" and causes that terrible ground noise that Amir measures:

 

Says a fellow styling himself "Magnum Innominandum:"

Having just come across this thread and having read the other one at a site that claims to cover audio science, I am surprised by the reasoning and logic that seems involved.

Hence I would like to raise an open question to Amir and anyone else, dispassionately and without appealing to emotions or creating FUD etc. about what this device or that thing does.

Amir claims "microRendu is highly sensitive to power supply noise.". And he posts measurements that he claims prove this when using a specific power supply from a specific manufacturer.

Meanwhile the power supply manufacturer posted measurements that show their power supply to have essentially no relevant noise in the output and Amir used the "noisy" power supply in a different setup, which showed no noise. Someone else also measured the power supply in question previously and shows practically no 50Hz mains noise (as the measurements were done in in England).

So we have:

1) An audio test system with a source that shows a lot of noise based on mains frequency. I am eyeballing perhaps 40uV of 60Hz noise in Amir's measurements if the scaling is as I expect.

2) The source is small computer plus a DAC both, powered via a DC power supply with additional local regulation in the computer as 9V powers neither USB nor Computer chips directly.

This local regulation should reduce any noise further and there is no 50/60Hz related switching frequency or AC power supply voltage anywhere within this source or attached to this source, other than the DC power supply.

3) A power supply with DC output powers this source. Based on several separate tests (including by Amir) this power supply has very low noise and no significant directly mains related noise on the output

Given these three simple facts I cannot reconcile Amir's original statement that: "microRendu is highly sensitive to power supply noise." with any currently known law of physics.

If the mico rendu did zero to reduce any incoming power supply noise, it could never produce more mains related noise on the output than it receives on the input.

Yet it would seem that Amir claims that somehow the micro rendu takes a few microvolt 100 (or 120Hz) noise and somehow creates more than ten times this level noise AND halves the frequency of this noise.

It would be nice if Amir would provide his scientific reasoning on the mechanisms in the micro rendu that create this noise out of apparently thin air.

If anyone else has suggestions as to how and why Amir's measurements would show much more mains related noise from the DAC output in the tested source than is actually input into the system by the power supply, I'd also appreciate the comments.

 

There is a reply from John Kenny, who knows a teensy bit about power supplies, ground noise, that sort of thing:

 

Hi M.I. - don't want to stoke up controversy but your question deserves an answer.

What iFi measurement shows is the correct way to measure the noise from the iPower SMPS power supply.

Now if this is done the wrong way i.e.with ground loop issues, then the noise measurement raises by a significant amount as they also show in their measurements. The reason for this being that the leakage noise which is part of every PS is not shunted to ground in the normal way but is instead being shunted through the Audio Precision's signal ground & appearing in the measurements

This is also what Amir's measurements shows - a ground loop issue.

I hope this answers your question?

 

plissken, would you care to tell us by what physics (apparently unknown to John Kenny, who designs and builds power supplies for a living) a resistor on ground would cause the measured effects noted by Magnum? I also see Kenny forgot to note that the designer of the microRendu must be "some idiot."

 

It appears Amir was careless in setting up his test rig, which can happen when you are set on debunking something of which you are skeptical, i.e., when you are bent on finding something and your results confirm your suspicions. This mindset was evident to me at a conversation I listened to between John, Alex, and Amir. Alex and John were unfailingly polite, perhaps more than I would have been. Other folks at WBF could easily have "confirmed" Amir's measurements by duplicating the error in his setup.

 

John has talked about the technical difficulty of providing the types of measurements that would be convincing with regard to the Regen, and about building a test rig that could do such measurements. (Though I do recall an EE who provided eye patterns showing favorable results from the Regen.) Of course he's also got a day job (with one of the world's leading semiconductor manufacturers - sad they have to stoop to hiring idiots) and designs audio equipment besides. So eager as I too am to see more sophisticated measurements, I will have to wait.

 

By the way, with regard to whose name is mud at What's Best Forum - Did Amir manage to complete his attempted surprise hostile takeover of the forum from his erstwhile partner the forum founder, or was he cast out of WBF?

[plissken]

 

plissken, would you care to tell us by what physics (apparently unknown to John Kenny, who designs and builds power supplies for a living) a resistor on ground would cause the measured effects noted by Magnum? I also see Kenny forgot to note that the designer of the microRendu must be "some idiot."

 

Sure:

"Lowest possible noise floor" than what? Not using microRendu? I don't think that is what they meant to put in their advertising copy. They like to make potential customers think that the noise floor is reduced with microRendu versus direct USB connection to the server. And that is the message that I have seen repeated over and over again by people after the announcement.

 

I just did a quick search on further statements on this and here is John Swensen saying this: http://www.computeraudiophile.com/f...nore-microrendu-27389/index30.html#post522581

 

"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 DACcircuit to operate at its peak performance. "

 

Pretty clear that he is telling people that DAC noise floor is reduced. Yet no such performance was shown in my measurements even with a linear power supply:

 

 

It appears Amir was careless in setting up his test rig

 

Keenly interested in your support of this

 

Amir can still post at WBF and as far as I'm aware still has a principal interest in WBF. May be that has changed but I'm unaware if that is the case as of now.

[plissken]

 

 

There is a reply from John Kenny, who knows a teensy bit about power supplies, ground noise, that sort of thing:

 

You can believe what you want to.

 

"Thanks JK, you have once again demonstrated you don't know what you are talking about.

 

You don't understand what a Y capacitor is or where it is in the circuit. Excuse the pun but "why" do you think I mentioned the lack of earth connection on the psu?

 

So quit the googling, you are not competent in this field.

 

Secondly another point that has been mentioned but you ignore is if you were correct (haha) any single ended hifi that has a connection to ground somewhere would suffer the same problem. Hence the psu would still be totally unsuitable. It's not just due to the AP.

 

You are ridiculed because of your repeated disruptive argumentative uninformed behaviour. No-one wants to listen to you. Don't you get it? People want you and your BS to go away. "

[sandyk]

You are ridiculed because of your repeated disruptive argumentative uninformed behaviour. No-one wants to listen to you. Don't you get it? People want you and your BS to go away.

 

Plissken

Are you 100% sure that this reply wasn't directed to you ?

It fits the bill perfectly !

[Jud]

plissken - Rather than continuing to hijack this thread, I invite you to be courteous to other folks possibly interested in the thread topic and post about the Regen to your heart's content in another thread I created specifically for the purpose:

 

http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/thread-where-plissken-may-slag-regen-he-likes-30283/#post595393

[plissken]

Read the OP again folks.

 

For the past 10 plus years USB has been a standard for consumer DAC's. It isn't routinely outperformed by other inputs and has the advantage of not being the source clock for the DAC.

 

I don't care what 3000 think. I care what 3000 people can demonstrate. I care what Alex can demonstrate, or what AQ can demonstrate.

 

The OP asked a question and I think it's been answered.

[plissken]

Plissken

Are you 100% sure that this reply wasn't directed to you ?

It fits the bill perfectly !

 

 

I see your wishful thinking is still as powerful as ever.

[sandyk]

The OP asked a question and I think it's been answered.

 

But not by you !

A Thread Where Plissken May Slag the Regen As He Likes

 

Seems that he is unwilling to stop his crapping all over this existing thread !

 

I would be happy to demonstrate through my own system, in the next couple of weeks, using my own files , to any interested Sydney member to report back to the forum whether the Uptone Regen does as claimed or not. I live in the Sydney suburb of Ermington if any Sydney member wishes to take me up on this.

They won't need to use pointless A/B testing either, as unless they are as frigging deaf as you obviously are, they will readily hear the improvements it makes for themselves, just as Sydney member Audiophile neuroscience and another Sydney member has already done, although I am prepared to do this myself with up to 20 pairs of .wav files if need be.

Not only that, I will show that the .wav files being compared STILL have identical .md5 checksums .

 

P.S.

You can safely bet your left one (or your right one) that Plissken will refuse to accept the results !!!

[Ralf11]

well, I've been using toslink to go from an Apple TV3 that catches my computer's WiFi and into a Cambridge Dacmagic.

 

should I unplug it and use a USB cable?

[Jud]

well, I've been using toslink to go from an Apple TV3 that catches my computer's WiFi and into a Cambridge Dacmagic.

 

should I unplug it and use a USB cable?

 

If it makes you happy, why change?

 

(I actually made the change from Toslink and coax to USB in slightly different circumstances years ago, and in my specific system I liked USB better. That doesn't mean USB will sound better to you in your system.)

 

If you're curious, just try a USB cable you have sitting around and see what you think.