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

[rb2013]

22 hours ago, Jud said:

 

At least as I understand what John has explained about the theory of operation, there are two aspects to it.

 

First, as with the original Regen, a cleaner signal allows the USB PHY receiver chip in the DAC to work less hard, creating less self-noise in the DAC circuitry.

 

Second, the isolation prevents both ground and leakage currents from utilizing the DAC circuitry as part of their pathways.

 

Both of these should help keep noise out of sensitive clock circuitry in the DAC, and the isolation should help to avoid some ground and leakage loops that might create noise in the overall system.

 

One comparison to the optical isolators you are familiar with is that although they provide isolation, they can have relatively high levels of self-noise and may therefore not be the best choice to use in DAC circuitry.

I believe JS spelled this out pretty clearly in his Tech Corner on the Regen.  Varying SI can cause the USB receiver AGC circuit to activate - then modulate - as the SI varies.  This AGC modulation causes noise on the ground plane that can 'jump' isolation schemes (even very good ones), and contaminate the sensitive femto clocks the DAC relies on.  Almost impossible to isolate.  Why ext USB DDC generally sound better then built in boards (know anyone that prefers the Yggy Gen 3 to a well powered SU-1 or even a F-1?).

 

This harkens back to days of of CD players where the DC servo laser tracking and rotor motor noise modulated high freq noise into the DAC side of the player.  Later transports and DAC separated to good effect, best to isolate the DAC PS from the spinner's.

 

It comes down to precise impedance matching (again even slight impedance variations will cause backwave reflections to wreck havoc on the USB receiver chip), noise isolation, maximizing SI strength and stability to min the AGC issues.

 

https://uptoneaudio.com/pages/j-swenson-tech-corner

"Remember that SI consists of rise/fall time, noise, and jitter. The jitter in the SIGNAL is determined by the transmitter PHY, which can be significantly influenced by the clock IT gets and the noise on its PG planes. USUALLY noise is low on the signal as it exits the PHY. The cable (and connectors) cause an increase in raise/fall times, added noise (EMI and crosstalk from power and ground wires) and decreased amplitude of the signal. Any decent receiver will have an automatic gain control (AGC) which compensates for this effect, but that raises the noise on the signal, so I'm lumping the amplitude decrease into noise. The cable by itself rarely adds jitter to the signal, BUT the increased rise/fall times and extra noise cause the received data to have increased jitter in the PHY. This is one of the big issues that all that extra processing is designed to deal with."

 

[Teresa]

On 6/2/2017 at 5:45 PM, Sal1950 said:

Are you really so scared that some bit of poor engineering will be revealed by Amir's measurements that you have to refuse a sale? ...Amir would never let any personal animosity to bias his results...

 

On 6/2/2017 at 5:57 PM, firedog said:

I think it is pretty clear that: a) Amir has an agenda which colors his work; b) isn't actually competent to do the measurements properly.

He also did let his biases influence what he wrote in his original evaluation of the Regen.

As Alex has said he would be fine giving one to other reviewers who do measurements, your post seems to have no basis.

 

Firedog is correct, Alex does have the right to refuse to sell his product to anyone, especially someone apparently with an agenda to do Alex's firm harm. Apparently your blind faith in Amir is incorrect.

 

This tread makes me glad I was never an audio designer or owner of an audio manufacturing firm, I don't have tough enough skin. In the USA a business has the right to refuse service to anyone as long as it doesn’t violate any anti-discrimination laws.

 

 

23 hours ago, Sal1950 said:

I've heard you refer to various successful blind tests involving the Reg but never found any actual details, sorry if I missed them...

 

23 hours ago, Jud said:

Alex sent me and @lmitche each two identical looking ISO Regens, asking us simply to listen and separately let him know what we thought.  The only difference between the two was a strip of blue painter's tape on the top of each, where in black magic marker the letter "G" was written on top of one, and the letter "M" was written on top of the other.

 

I plugged each ISO Regen into my system in place of the original Regen.  I only had to listen to each once to know that I very much preferred "G."  The whole thing took maybe five minutes because the difference was so apparent.  (I liked both G and M better than the original, but of course that comparison was non-blinded.)

 

Afterward I learned @lmitche's experience was pretty much a carbon copy of mine.

 

22 hours ago, Sal1950 said:

Well there ya go.  You should present that as a paper to the AES.  LOL

 

10 hours ago, firedog said:

Jud did exactly the reasonable thing an audiophile should do at home. Blind test comparison to see what sounds better. He had no financial or other incentive at the time to prejudice his results. For someone who constantly flogs here about ofjectivism, your reaction is uncalled for wise-assness.

 

Doubtful anyone, including you, has the ability to do scientifically correct double blind testing at home. Even a perfectly done test just on yourself or a few individuals wouldn't count as scientifically valid, as the test group would be small. 

 

So Sal do you understand now? Also, have you ever presented a paper to the AES on a how you evaluated the audio equipment you own? 

[The Computer Audiophile]

10 minutes ago, plissken said:

Not saying that at all. What I am saying is that in all respects we know that $800 makes available more DAC's for evaluation and choose from. Some even are Ethernet devices that obliterate the problem child USB bus for a much more stable connection. 

 

Just spent eight hours over the last few days troubleshooting an Ethernet audio issue from 1,500 miles away. After exhausting all feasible solutions, we switched to the USB connection in the same DAC and music has been playing for 8 hours without a hiccup. 

 

I love Ethernet audio when I have 100% control over the network. I'm using it as I type this. When another company installs and controls several switches and APs, and I only control a single dedicated switch for audio, problems can mount and turn into a cluster "F" trying to track them down (and dealing with stereotypical IT guys who say the network is perfect).

[rb2013]

BTW in the AOIP thread on HF I started address some of these USB shortcomings.  The AES67 protocol implemented by Audinate with DANTE - was quite good. Unfortunately these REDNET proaudio boxes use quite crappy SMPS.

 

I found the better solution to this with the Startech/ICRON GB LAN Ethernet USB extenders - there you have the majority of USB's addressed and SI completely reconstructed in an isolated SPARTAN 6 FPGA (later a custom ASIC).  Across a GI UTP CAT6 bridge.  The REX completely reconstructs the USB packets from TCPIP packets (with full error correction), away from the PC USB VBUS.  Fed it's own low noise LPS.

 

Taken to another level with music files played from SLC mSD in that isolated REX - using the same UTP bridge.  

 

The ISO Regen is major step forward on many levels - providing GI without the Intona's noise issues, SI and impedance improvement, and using multiple ultra low noise LT3042 regulators.  So where and how do you measure all that it's doing?  Point less to try.

 

I laugh - reminds me of the Japanese amp wars of the '70s - Pioneer vs Sansui vs Kenwood vs Yamaha.  Who had the lowest IM and THD - as measured in Audio and High Fidelity Magazines.

 

But Harry Person (and others) blew the lid off that - with his 'reviews' - recommending ARC and CJ tube gear!  

Test-bench heroes were catatonic...so where is Yamaha, Kenwood, Sansui, Pioneer, Yamaha today?  Making car stereos (aside from Yammie), and ARC and CJ (and MaC) are still doing a bang up business.  Why? Because those 'measurements' meant very little - what mattered was the sound people heard.

[plissken]

17 minutes ago, The Computer Audiophile said:

 

Just spent eight hours over the last few days troubleshooting an Ethernet audio issue from 1,500 miles away. After exhausting all feasible solutions, we switched to the USB connection in the same DAC and music has been playing for 8 hours without a hiccup. 

 

I love Ethernet audio when I have 100% control over the network. I'm using it as I type this. When another company installs and controls several switches and APs, and I only control a single dedicated switch for audio, problems can mount and turn into a cluster "F" trying to track them down (and dealing with stereotypical IT guys who say the network is perfect).

 

Part of the issue is how vendors CoughAurelicCough approach setup to be honest. The best way is to:

 

1. Assign a static IP from the factory something like 192.168.168.168

2. Standard web interface for managing this. 

 

If vendors figured this out it would go much smoother. I've helped two members resolve their Ethernet connected end points and both have been improper network configuration (no fault of the vendor) and really screwy and over complicated setup routine for the device in question (certainly a fault of the vendor). 

 

In both cases in 10 minutes I had the causal root nailed down. 

[Fitzcaraldo215]

21 minutes ago, Teresa said:

 

 

Firedog is correct, Alex does have the right to refuse to sell his product to anyone, especially someone apparently with an agenda to do Alex's firm harm. Apparently your blind faith in Amir is incorrect.

 

Teresa - true, Alex has the right to refuse the sale.  But, while Alex is entitled to his opinion justifying his action, there is no evidence anywhere that Amir has "an agenda to do Alex's firm harm." None.  Zero. Alex insists and states a lot of things about Amir, but none are independently proven anywhere.  None.  Zero.

 

 But, I can see where the stampede of opinions here and deep sympathies for Alex at CA might lead you and others to assume something negative about Amir, who is not known here, based purely on Alex' say so, which may or may not be truthful.

[jabbr]

27 minutes ago, rb2013 said:

I believe JS spelled this out pretty clearly in his Tech Corner on the Regen.  Varying SI can cause the USB receiver AGC circuit to activate - then modulate - as the SI varies.  This AGC modulation causes noise on the ground plane that can 'jump' isolation schemes (even very good ones), and contaminate the sensitive femto clocks the DAC relies on.  Almost impossible to isolate.  Why ext USB DDC generally sound better then built in boards (know anyone that prefers the Yggy Gen 3 to a well powered SU-1 or even a F-1?).

 

This harkens back to days of of CD players where the DC servo laser tracking and rotor motor noise modulated high freq noise into the DAC side of the player.  Later transports and DAC separated to good effect, best to isolate the DAC PS from the spinner's.

 

It comes down to precise impedance matching (again even slight impedance variations will cause backwave reflections to wreck havoc on the USB receiver chip), noise isolation, maximizing SI strength and stability to min the AGC issues.

 

Uh ok lots and lots of speculation and hypotheticals ... but your bottom line is that the sensitive femto clock is "contaminated" so at some point you have a measurable prediction. If there is an alternation in the clock, this is measureable. We've outlined several methods to do this. Some with very expensive equipment, some with more moderately expensive equipment. So let's see the data.

 

I mean if we are literally "wreck havoc" to the USB chip, this is easily measurable... theory sounds good ... heard it and understand it ... it makes predictions, so lets see the data. I've outlined a very specific measurement: one that requires an expensive phase error measurement system (expensive) and one that requires a good spectrum analyzer (not as expensive)

 

27 minutes ago, rb2013 said:

 

https://uptoneaudio.com/pages/j-swenson-tech-corner

"Remember that SI consists of rise/fall time, noise, and jitter. The jitter in the SIGNAL is determined by the transmitter PHY, which can be significantly influenced by the clock IT gets and the noise on its PG planes. USUALLY noise is low on the signal as it exits the PHY. The cable (and connectors) cause an increase in raise/fall times, added noise (EMI and crosstalk from power and ground wires) and decreased amplitude of the signal. Any decent receiver will have an automatic gain control (AGC) which compensates for this effect, but that raises the noise on the signal, so I'm lumping the amplitude decrease into noise. The cable by itself rarely adds jitter to the signal, BUT the increased rise/fall times and extra noise cause the received data to have increased jitter in the PHY. This is one of the big issues that all that extra processing is designed to deal with."

 

What kind of jitter do you mean, exactly? Jitter is eminently measurable.

@PeterSt has demonstrated what look at first glance like some very good "jitter" measurements. Can those be beat? Can that be heard?

[Daudio]

29 minutes ago, Fitzcaraldo215 said:

no evidence anywhere that Amir has "an agenda to do Alex's firm harm."

 

Maybe nothing that would work in Court, but so what ? There's a strong supposition, that is likely enough. And his bias is evident from many of his writings. But, regardless, his improper testing procedures have been uncovered, so his intent doesn't really matter, his output is simply untrustworthy.

 

[Teresa]

16 minutes ago, Fitzcaraldo215 said:

Teresa - true, Alex has the right to refuse the sale.  But, while Alex is entitled to his opinion justifying his action, there is no evidence anywhere that Amir has "an agenda to do Alex's firm harm." None.  Zero. Alex insists and states a lot of things about Amir, but none are independently proven anywhere.  None.  Zero.

 

 But, I can see where the stampede of opinions here and deep sympathies for Alex at CA might lead you and others to assume something negative about Amir, who is not known here, based purely on Alex' say so, which may or may not be truthful.

 

Actually, it is not important what you or I believe, it's what Alex believes that is important as it is his product and his company. If he doesn't trust Amir to accurately test his product, he doesn't.

[plissken]

10 minutes ago, Daudio said:

 

Maybe nothing that would work in Court, but a strong supposition, that is likely enough. And his bias is evident from many of his writings. But, regardless, his improper testing procedures have been uncovered, so his intent doesn't really matter, his output is simply untrustworthy.

 

 

As far as I'm aware: if Amir has been made aware of issues WRT measurements he corrects them if they indeed need corrected. 

 

Now as is typical of me I'm going to ask for links to any current measurements that Amir is standing by at the moment that are incorrect. And as is typical no linkage will be forthcoming. 

[kumakuma]

10 minutes ago, Fitzcaraldo215 said:

Teresa - true, Alex has the right to refuse the sale.  But, while Alex is entitled to his opinion justifying his action, there is no evidence anywhere that Amir has "an agenda to do Alex's firm harm." None.  Zero. Alex insists and states a lot of things about Amir, but none are independently proven anywhere.  None.  Zero.

 

 But, I can see where the stampede of opinions here and deep sympathies for Alex at CA might lead you and others to assume something negative about Amir, who is not known here, based purely on Alex' say so, which may or may not be truthful.

 

The fact that Amir felt the need to complain about this tells me everything I need to know about the guy. He appears to be determined to embarrass Alex in any way he can whether it's through measurements or by "exposing" his business practices. Alex has moved on. Why hasn't Amir?

[Jud]

59 minutes ago, plissken said:

 

Not saying that at all. What I am saying is that in all respects we know that $800 makes available more DAC's for evaluation and choose from.

 

Sure, fair point.  At that price point I'd be interested in the TEAC stuff.

 

59 minutes ago, plissken said:

Some even are Ethernet devices that obliterate the problem child USB bus for a much more stable connection. 

 

I think to some degree the problems with USB are a combination of popularity and people seeking ever-better performance.  I would guess if/when Ethernet becomes popular we might see something along similar lines.

 

59 minutes ago, plissken said:

I'd put the $320 I paid for my Stealth DC-1 up against your combo any day of the week. 

 

I'm very glad you're happy with your system.  I like playing with filters/modulators, so my DAC works nicely for that.

 

59 minutes ago, plissken said:

Now if you want to have a dialectic about $349 + $655 in upstream gadgetry vs $1000 spent in some other fashion well I'm all up for that. 

 

What gizmos are you referring to at those price points?

[The Computer Audiophile]

@plissken

 

Some of his measurements and narrative are similar to this example, make sure you read the entire thing and come back often to see if it has been updated / corrected.

 

 

 

 

CLIMATE CHANGE IS A HOAX

CLIMATE CHANGE IS A HOAX

CLIMATE CHANGE IS A HOAX

CLIMATE CHANGE IS A HOAX

CLIMATE CHANGE IS A HOAX

CLIMATE CHANGE IS A HOAX

 

 

 

 

 

just received info from scientific community ...

 

 

i guess it's real.

 

 

 

[plissken]

2 minutes ago, Jud said:

 

Sure, fair point.  At that price point I'd be interested in the TEAC stuff.

 

 

I think to some degree the problems with USB are a combination of popularity and people seeking ever-better performance.  I would guess if/when Ethernet becomes popular we might see something along similar lines.

 

 

I'm very glad you're happy with your system.  I like playing with filters/modulators, so my DAC works nicely for that.

 

 

What gizmos are you referring to at those price points?

ISO Regen and a Power Supply...

 

[plissken]

3 minutes ago, The Computer Audiophile said:

@plissken

 

Some of his measurements and narrative are similar to this example, make sure you read the entire thing and come back often to see if it has been updated / corrected.

 

 

 

 

CLIMATE CHANGE IS A HOAX

CLIMATE CHANGE IS A HOAX

CLIMATE CHANGE IS A HOAX

CLIMATE CHANGE IS A HOAX

CLIMATE CHANGE IS A HOAX

CLIMATE CHANGE IS A HOAX

 

 

 

 

 

just received info from scientific community ...

 

 

i guess it's real.

 

 

 

 

If people are saying the measurements are problematic then there should be no problem linking to it. I'm able to generally provide links to papers and files when I'm talking about those particulars. 

[The Computer Audiophile]

Just now, plissken said:

 

If people are saying the measurements are problematic then there should be no problem linking to it. I'm able to generally provide links to papers and files when I'm talking about those particulars. 

 

What I was trying to demonstrate with my example, was someone who takes measurements and screams at the top of his lungs about faulty equipment. Then, after people point out errors in the measurements, techniques, or analysis, the articles are updates without much fanfare. 

 

You can't unring a bell. 

[Jud]

2 minutes ago, plissken said:

ISO Regen and a Power Supply...

 

 

I'm seeing $310 for the ISO Regen without power supply, $325 with switching supply, and $655 total for an ISO Regen bundled together with an ultracapacitor power supply.

[jabbr]

45 minutes ago, rb2013 said:

But Harry Person (and others) blew the lid off that - with his 'reviews' - recommending ARC and CJ tube gear!  

Test-bench heroes were catatonic...so where is Yamaha, Kenwood, Sansui, Pioneer, Yamaha today?  Making car stereos (aside from Yammie), and ARC and CJ (and MaC) are still doing a bang up business.  Why? Because those 'measurements' meant very little - what mattered was the sound people heard.

 

I love tubes and love the sound. I also love jFets ... my issue is when a very detailed technical explanation is proposed that makes specific technical predictions, then there is some degree of obligation to support this with reasonable measurements. I think it comes down to my objection to using the term "jitter" for marketing purposes without any evidence that "jitter" is actually being affected. ... but I guess this is just marketing...

[plissken]

5 minutes ago, The Computer Audiophile said:

 

What I was trying to demonstrate with my example, was someone who takes measurements and screams at the top of his lungs about faulty equipment. Then, after people point out errors in the measurements, techniques, or analysis, the articles are updates without much fanfare. 

 

You can't unring a bell. 

 

Got it. Still he updates the OP with any updates and addendum. I think a way of combating this is for manufacturers, like Emotiva, to perform and post their own measurements. 

[The Computer Audiophile]

1 minute ago, plissken said:

 

Got it. Still he updates the OP with any updates and addendum. I think a way of combating this is for manufactures, like Emotiva does, to perform and post their own measurements. 

 

I agree, measurements posted by manufacturers would be good. I don't think everyone would believe those measurements though. 

 

Perhaps a technical editor could be used before publishing potentially damaging claims. 

[plissken]

1 minute ago, The Computer Audiophile said:

 

I agree, measurements posted by manufacturers would be good. I don't think everyone would believe those measurements though. 

 

Perhaps a technical editor could be used before publishing potentially damaging claims. 

 

Again, the best defense against slander is the truth. As long as the measurements are done in a way to enable 3rd parties and they achieve the same results then things are copacetic. 

[The Computer Audiophile]

Just now, plissken said:

 

Again, the best defense against slander is the truth. As long as the measurements are done in a way to enable 3rd parties and they achieve the same results then things are copacetic. 

 

I'm with you.

[christopher3393]

9 minutes ago, plissken said:

 

Again, the best defense against slander is the truth. As long as the measurements are done in a way to enable 3rd parties and they achieve the same results then things are copacetic. 

 

8 minutes ago, The Computer Audiophile said:

 

I'm with you.

 

But is it always practical? And do the results from available testing always indicate to the potential listener what value the product may have? While this is a good general guideline, it sounds to me like some demand this in all cases. This strikes me as very unreasonable.

[plissken]

Just now, christopher3393 said:

 

 

But is it always practical? And do the results from available testing always indicate to the potential listener what value the product may have? 

 

If you are in the business of designing audio equipment I should expect so. You can either get the equipment in house or you can send out product to a lab for measurement.

 

So let me ask this:

 

Is it acceptable for a company to design with a shoot from the hip approach where they actually have no way to analyze what their equipment is doing? 

[rb2013]

36 minutes ago, jabbr said:

 

Uh ok lots and lots of speculation and hypotheticals ... but your bottom line is that the sensitive femto clock is "contaminated" so at some point you have a measurable prediction. If there is an alternation in the clock, this is measureable. We've outlined several methods to do this. Some with very expensive equipment, some with more moderately expensive equipment. So let's see the data.

 

I mean if we are literally "wreck havoc" to the USB chip, this is easily measurable... theory sounds good ... heard it and understand it ... it makes predictions, so lets see the data. I've outlined a very specific measurement: one that requires an expensive phase error measurement system (expensive) and one that requires a good spectrum analyzer (not as expensive)

 

What kind of jitter do you mean, exactly? Jitter is eminently measurable.

@PeterSt has demonstrated what look at first glance like some very good "jitter" measurements. Can those be beat? Can that be heard?

Not my bottomline but John's...I imagine you could 'test' it.  But using a static 1kHz test tone - is not real world.  You would need to fed the USB chain a realistic complex and dynamic musical data chain.  Like Dark Matter and Dark Energy - I suppose it would be near impossible to directly observe and measure (did I add Heisenberg's Measurement issue?), but possibly some artifact could be.  As with DM and DE their theoretical gravitation effects.  But then you open another can of worms..no?  Are those supposed artifacts truly there in the way your theory expects or predicts.  A true Gordian knot.

 

So in this case the issues JS mention AGC modulated noise on the PG, SI integrity being the culprit, but also impedance issues.  So again theoretically all USB cables have perfect 90ohm impedance..but how accurately is that spec?  How much variation and in a real world there will always be some variation - is important?  What about the .50cent USB input connector?  Does it have 'perfect' impedence.

 

I guess the issue with USB and really all digital - it the level of precision and isolation needed to extract the best SQ.  Way beyond that eyeballing of a cart RA, skew and VTA.  We are talking clocks with 1ppm or even ppb accuracy - supposedly.  Can all these factors be measued simulateoulsy?  With a real world music file?

 

Maybe in 20 yr or 50 yrs - but not in any near future.  Although I do appaud and enjoy the efforts.  I credit Amir for catching the 'glitching' in the Yggy's AD5791BRUZ chips.  Glitching being one of the banes of R2R DAC's.  While not my cup of tea - it seems folks like the Yggy and the sales continue briskly...so this is all fun and games.  The ONLY truth is the smile on one's face while listening to great music.