Amir at ASR claims Uptone won't sell the ISO regen to him...

[esldude]

7 minutes ago, mansr said:

I was fooling around with an old Cambridge Audio AVR recently. As it turned out, feeding it an unexpected, but in-spec, S/PDIF signal made it emit smoke.

I have had that happen with tweeters before in some of my test to destruction activities.  Unintentional destruction, but same result.

[jabbr]

5 minutes ago, esldude said:

This is what I described.  And no the Crystek graph has no single peak it actually starts at 10 hz from the carrier.  I lined my graph up so the edge is lined up with the peak.  So you are seeing the upper sideband.  I am not measuring a 100 mhz clock.  I am measuring the 12 khz tone of a DAC.  No I don't have 1 microhertz resolution.  If I did, the 1 hz wide level would measure somewhere close to the same. 

 

Now part of the reason I posted this is to show you are comparing apples and oranges in one sense.  Yet if you wished to do comparisons this way it would be valid as far as it goes.  Same idea different frequencies.  Lower jitter will net better results on such a graph.  Not all types of jitter mind you which is another problem with the assumption close in jitter is of large importance. 

 

Ah ok  I misinterpreted what you were doing ... 

 

Yes lower close-in phase error will get a more narrow peak. This is math. I know this is a new concept that doesn't appear to be widely described but I am very confident of the underlying math. 

 

Let me pose this question to you: you fed a 12kHz pure tone in, right, so where did the non precisely 12 kHz stuff come from on the FFT? How did it get there?

 

 

[Jud]

3 minutes ago, plissken said:

You were comparing items that most likely have very measureable differences in output

 

You mean two versions of the ISO Regen that everyone has been going on for pages here wondering how to measure any differences from?

 

What exactly do you expect would be so wildly out of spec between two versions of USB-hub-with-isolator-chip, and what measurements or examination of the circuit topology are you basing these strange accusations on?  You talked about 120V - are you seriously thinking a USB hub will be sending that or anything else similarly far out of spec to a DAC, and that the DAC would still be playing music if it did?  Or that differences in *sound quality* would result from a comparison between two hubs that were so severely compromised?

 

Talk about needing new physics to explain some people's weird ideas....

[mmerrill99]

2 minutes ago, jabbr said:

 

Ah ok  I misinterpreted what you were doing ...

 

Yes lower close-in phase error will get a more narrow peak. This is math. I know this is a new concept that doesn't appear to be widely described but I am very confident of the underlying math. 

 

 

The point is he has absolutely no idea what portion of the close in phase noise is accounted for by the ADC jitter or the DAC jitter so if he then proceeded to measure a ISO Regen in front of the DAC & got exactly the same plot he might well declare that the ISO Regen has no effect.

 

This is called measurement Amir-style

[esldude]

5 minutes ago, jabbr said:

 

Ah ok  I misinterpreted what you were doing ...

 

Yes lower close-in phase error will get a more narrow peak. This is math. I know this is a new concept that doesn't appear to be widely described but I am very confident of the underlying math. 

 

 

I don't know that it is new.  Perhaps the importance of how narrow the central peak is has been overlooked or considered unimportant. 

 

On a graph like this where would you wish to measure it.  1 hz either side of the peak, 10 hz?  What level is telling in your opinion?  With matlab one can measure to about any size FFT you desire.  You have to be really careful with relative clock timing to even get what I have shown you here.

 

[Jud]

12 minutes ago, mansr said:

I was fooling around with an old Cambridge Audio AVR recently. As it turned out, feeding it an unexpected, but in-spec, S/PDIF signal made it emit smoke.

 

Yes, that's just what happened with my DAC - black smoke with one hub, white smoke with the other, so of course I knew which one to choose as Regent, er, Regen.

[mmerrill99]

5 minutes ago, Jud said:

 

Yes, that's just what happened with my DAC - black smoke with one hub, white smoke with the other, so of course I knew which one to choose as Regent, er, Regen.

One was elected Papal Regent by decree of the Archbishops - an infallible blind test, I would say

[jabbr]

21 minutes ago, esldude said:

I don't know that it is new.  Perhaps the importance of how narrow the central peak is has been overlooked or considered unimportant. 

 

On a graph like this where would you wish to measure it.  1 hz either side of the peak, 10 hz?  What level is telling in your opinion?  With matlab one can measure to about any size FFT you desire.  You have to be really careful with relative clock timing to even get what I have shown you here.

 

Its not "new" scientifically (I am not rushing this to publication  but there seems to be a general lack of understanding as to exactly what measurements are needed in order to measure the effects of phase error. There are other types of cross talk "jitter" that cause even more distortion.

 

I'm trying to give people who publish wideband FFTs with spectrum analyzers the benefit of the doubt in not knowing exactly what measurements should be done. Does the Regen decrease clock jitter at the DAC? Who knows. Would it be audible? Who knows? For all I know it could all be leakage current/grounds loops or even something else.

 

In the absence of measurements I have no opinion on this. What degree is audible? That can be determined once we have good measurements. Good measurements are hard to do and take work. I don't mean to criticize your equipment because you are a hobbyist and you are spending your time and effort. That said, its particularly hard to disprove something with a less than optimal measurement. One reason that measurements haven't been done has been stated that the currently available equipment is not good enough to show the difference. I've pointed out that equipment from the 1980s was probably good enough. So I've set what I consider a reasonable standard. To be very clear this equipment has been extremely expensive (you are paying $$$ for these types of specs) and out of the range for a small audio company. 

 

Ebay to the rescue! I'm picking up equipment for literally pennies on the dollar ... all in the dream that someday my kids' activitiies will start to slow down enough that I can sit ... in the meantime I can post from hockey rinks, or lacrosse fields, while waiting for a game to start, or between games, otherwise we could go to a bar and drink beer... or both ... well there are many games in the morning and there's only so much coffee I can drink ...

 

Regarding the technical factors: if the frequency increments are not small enough it can cause quantization error (for lack of a better term) in which either side bands can be blurred or side bands can be created.  I am not talking about harmonic distortion, for example, so when there is a high resolution spectrum available it greatly eases interpretation.

[jabbr]

I've posted this before, but the "linewidth" term I am using comes from the laser spectroscopy field where its used as a measure of phase error: https://en.wikipedia.org/wiki/Oscillator_linewidth

 

Also, Page 7 entitled "What is Phase Noise?" has an excellent diagram of what I am talking about. http://www.keysight.com/upload/cmc_upload/All/PhaseNoise_webcast_19Jul12.pdf?&cc=US&lc=eng

[mmerrill99]

 

35 minutes ago, jabbr said:

I'm trying to give people who publish wideband FFTs with spectrum analyzers the benefit of the doubt in not knowing exactly what measurements should be done. Does the Regen decrease clock jitter at the DAC? Who knows. Would it be audible? Who knows? For all I know it could all be leakage current/grounds loops or even something else.

Yes close in phase noise, common mode noise, leakage currents (all possible aspects that are improved with the ISO Regen) will not be amenable to analysis by an AP SYS2722 analyser - it takes some effort & experience to decide what is an appropriate measurement & what is needed to achieve this measurement - man with AP does not qualify.

[jabbr]

2 hours ago, esldude said:

The dotted line at 10.3 hz offset would give just short of 45 dbc/hz.   The inserted result at 1.5 hz is just short of 40 dbc/hz.

 

Ok so let's consider whether these numbers are audible (except that the values will rise as the offset lessens...)

 

Consider: http://www.phy.mtu.edu/~suits/notefreqs.html these are bass admittedly but look how close the notes are together in Hz ... so could the 1Hz offset phase error have a significant effect? A "blur" function of the FFT of a song using Matlab might be close ...

[Ralf11]

6 hours ago, Jud said:

 

Then you will want to take along with you the next time you buy lottery tickets the customer in the ISO Regen launch thread who on April 26th of this year noted the 30 day risk free trial for it, since he apparently foresaw it on the website more than a month in advance of when you say it appeared.

 

An imaginary customer?

 

You are certainly a vociferous advocate for this co. - do you have any sort of relation with them?

[mmerrill99]

17 minutes ago, jabbr said:

 

Ok so let's consider whether these numbers are audible (except that the values will rise as the offset lessens...)

 

Consider: http://www.phy.mtu.edu/~suits/notefreqs.html these are bass admittedly but look how close the notes are together in Hz ... so could the 1Hz offset phase error have a significant effect? A "blur" function of the FFT of a song using Matlab might be close ...

Yes, this might be a more profitable parallel line of investigation - find some way of simulating  close in phase issues in songs (not single test tones) & test for audibility Vs level & characteristics.

 

Have any audibility tests of this nature been conducted before?

 

Is it worth thinking about this in terms of image processing i.e. motion blur in video?

[Ralf11]

4 hours ago, Daudio said:

 

Dance, monkey, dance... 

 

 

I expect it is difficult to endure some of the comments here, but your comments are not furthering your business.

[keesue]

 

11 hours ago, pkane2001 said:

Since John Swenson says that he doesn't have the instrumentation to measure the effect on jitter (yet), then any audible improvement claimed for the device, at least for now, must remain a conjecture, an educated guess.

 

As succinct as it gets.  

[JR4321]

I will send my Regen to Amir so he can publish the measurements.  Should be interesting.  I don't use it anyway.

[Ralf11]

The cause of "any audible improvement... at least for now, must remain a conjecture, an educated guess."

 

But a blind test can reveal whether it sounds better without knowing why (or maybe not caring).  It is not expensive and there is a 30 day return privilege.  So people can simply listen to it - carefully, and blind.

 

I'd be curious to find out if it improves some DACs and not others.

[plissken]

11 hours ago, pkane2001 said:

Since John Swenson says that he doesn't have the instrumentation to measure the effect on jitter (yet), then any audible improvement claimed for the device, at least for now, must remain a conjecture, an educated guess.

 

I'm at a loss how:

 

1. You can guess at a problem that you can't quantify so you can see what's going on but...

 

2. Still develop a solution 'in the blind' for it (whatever 'it' is)

[pkane2001]

8 minutes ago, plissken said:

 

I'm at a loss how:

 

1. You can guess at a problem that you can't quantify so you can see what's going on but...

 

2. Still develop a solution 'in the blind' for it (whatever 'it' is)

 

And once you have developed such a solution, how do you know that it achieves the desired goal? More to the point, how do I know this, if you can't provide objective data?

[pkane2001]

18 minutes ago, Ralf11 said:

The cause of "any audible improvement... at least for now, must remain a conjecture, an educated guess."

 

But a blind test can reveal whether it sounds better without knowing why (or maybe not caring).  

 

A difference found in a double-blind test does not prove an actual improvement. It proves that there is a difference between A and B samples, but which one is better is based on the listener and their preferences and therefore is not objective.  

 

Consider the online survey where the majority of 150 listeners preferred a flawed MP3 lossy compression over the non-lossy original in a blind test using their own equipment. Over 55% of folks with high-end, expensive equipment preferred the sound of the less accurate recording and only 29% preferred the lossless version. Does that mean that MP3 is better?

[STC]

2 minutes ago, pkane2001 said:

 

A difference found in a double-blind test does not prove an actual improvement. It proves that there is a difference between A and B samples, but which one is better is based on the listener and their preferences and therefore is not objective.  

 

Consider the online survey where the majority of 150 listeners preferred a flawed MP3 lossy compression over the non-lossy original in a blind test using their own equipment. Over 55% of folks with high-end, expensive equipment preferred the sound of the less accurate recording and only 29% preferred the lossless version. Does that mean that MP3 is better?

 

I am beginning to think 320 MP3 is quite enjoyable for long term listening.  

 

 

[kumakuma]

1 hour ago, Ralf11 said:

 

I expect it is difficult to endure some of the comments here, but your comments are not furthering your business.

 

I think you have confused him with Alex (SuperDad).

[Ralf11]

yes sorry - I got hung up on the "D"

[PeterSt]

1 hour ago, keesue said:

As succinct as it gets.

 

Not bad at all for a first post and being member for so long.

haha

[PeterSt]

1 hour ago, JR4321 said:

I will send my Regen to Amir so he can publish the measurements.  Should be interesting.

 

Does anyone actually have a clue about what measurements he is waiting for ?

I most certainly can't think of any, unless such a device is going to make all significantly worse.

 

An eye diagram is one but I don't really call that measurement as such.

So name us some type of measurement which is going to show something (doesn't need to be significant - marginal is OK too) and which someone like me won't debunk beforehand.

Could be fun !