Objective proof the UpTone Regen ISO can improve a DAC's output(*)

[scan80269]

So are 60Hz & harmonics at -110dbFS or lower amplitudes supposed to be audible at the DAC output or not?

 

[esldude]

32 minutes ago, scan80269 said:

So are 60Hz & harmonics at -110dbFS or lower amplitudes supposed to be audible at the DAC output or not?

 

They are not going to be audible. 

 

Though as a consumer I don't think I would be happy to spend money on a device meant to isolate my system from noise and have it make the 60 hz PS noise 20 db worse than it otherwise is without that device.

[plissken]

56 minutes ago, lmitche said:

Yes, I read Amir's response before making my post above that contains a recommendation that will likely fix Amir's testbed.

 

But there's nothing wrong with his test bed. Swap out the AP for a USB controlled pre-amp. It's a perfectly legit setup that is in many homes. 

[scan80269]

1 minute ago, esldude said:

They are not going to be audible. 

 

Though as a consumer I don't think I would be happy to spend money on a device meant to isolate my system from noise and have it make the 60 hz PS noise 20 db worse than it otherwise is without that device.

To me it looks like the Mean Well SMPS is more of a culprit than the ISO REGEN in this particular aspect.  The Mean Well was not designed by UpTone, so I suppose it can be argued that it isn't the best choice for bundling with ISO REGEN, but then I suspect an improved PS in this regard will cost substantially more than the Mean Well...

 

[plissken]

54 minutes ago, scan80269 said:

And I suggested yesterday that Amir replace the Mean Well SMPS with a battery to power the ISO REGEN and re-measure.  A purely scientific control experiment with only one component changed.

 

UpTone's LPS-1 power supply should also do the trick, but given Amir's obvious anti-UpTone stance, I thought a battery would at least be "neutral territory".  

 

 

But the ISO Regen is supposed to be an isolating device. You are now advocating ANOTHER isolation device to help with an isolation device. 

 

So lets say that Amir puts a battery on the ISO Regen and the 60Hz AC mains leakage current goes away. You are simply saddled with a parts heavy configuration that gets you back to running the Behringer 204HD straight cabled from from the computer. 

[plissken]

54 minutes ago, lmitche said:

When we had this same conversation about the Amber Regen I was told that no one has an isolation transformer in their audio systems. My response was that no one has an AP in their audio systems. Clearly care must be taken to ensure that the testbed doesn't impact the results especially when those results are posted in a public forum.

 

The 60 Hz mains AC leakage noise isn't there with the AP in the loop though. Again, Amir and BE17 pointed this out: The AP for all intents and purposes is just another piece of audio gear.  It is what it is and no matter the amount of swinging away you want to do is going to change that fact. 

[plissken]

43 minutes ago, scan80269 said:

So are 60Hz & harmonics at -110dbFS or lower amplitudes supposed to be audible at the DAC output or not?

 

 

Nope. But it's measurably making things worse and it's antithetical to the sales pitch given about the device. 

[plissken]

6 minutes ago, scan80269 said:

To me it looks like the Mean Well SMPS is more of a culprit than the ISO REGEN in this particular aspect.  The Mean Well was not designed by UpTone, so I suppose it can be argued that it isn't the best choice for bundling with ISO REGEN, but then I suspect an improved PS in this regard will cost substantially more than the Mean Well...

 

 

Or it could be that a better power supply powering the DAC directly would do the trick sans a regenerator. 

[scan80269]

My understanding is that it was not a design goal of the ISO REGEN to be effective against AC leakage loops.  Based on the components I can see on the ISO REGEN circuit board it has no capability to block AC leakage loops.

 

The design intent of ISO REGEN is to act as a noise firewall for USB, specifically between the upstream-facing and downstream-facing USB ports.  That the design utilizing external DC feed-in for the downstream logic resulting in elevated AC leakage that is measurable at the DAC output can be considered unfortunate, though I believe Alex or John has explained the rationale behind this design decision, and I assume they have properly weighed the pros and cons.

 

If you want a USB de-crapifier that is completely USB bus powered, it's called Intona USB isolator.  By its design it does not create an additional AC leakage loop in the system.  But don't be surprised if its sonic benefits differ from those with the ISO REGEN.  There's a small SMPS on the Intona circuit board, BTW.

 

 

[scan80269]

Between "measurably worse but sounds better" and "measurably better but sounds worse" I'll always take the former.

 

I bought a Benchmark AHB2 amp not because of its fantastic specs but because of how it sounds.  Fastest and clearest solid state amp I have ever heard.

 

[elcorso]

5 minutes ago, plissken said:

 

But the ISO Regen is supposed to be an isolating device. You are now advocating ANOTHER isolation device to help with an isolation device. 

 

So lets say that Amir puts a battery on the ISO Regen and the 60Hz AC mains leakage current goes away. You are simply saddled with a parts heavy configuration that gets you back to running the Behringer 204HD straight cabled from from the computer. 

 

Dear Pliss,

 

Thanks to you I'm just buying a Behringer 204HD from Amazon.  If I don't like it (the SQ) I will sell to some friend  who, thanks to you, want it and don't like to buy items by the internet.

 

I'll try it straight and then with the ISO Regen, but, with the CAPS.  This IR made magic on my Lampi B7.  I have some oscilloscope that I use only for repairs, not to 'listen' the unlistenable...

 

Roch

[lmitche]

13 minutes ago, plissken said:

 

The 60 Hz mains AC leakage noise isn't there with the AP in the loop though. Again, Amir and BE17 pointed this out: The AP for all intents and purposes is just another piece of audio gear.  It is what it is and no matter the amount of swinging away you want to do is going to change that fact. 

Scan and I have provided useful advice that would help Amir improve his testbed and objective evaluation of the ISO Regen based on real world experience.  Let's see what Amir chooses to do.

[plissken]

5 minutes ago, scan80269 said:

My understanding is that it was not a design goal of the ISO REGEN to be effective against AC leakage loops.  Based on the components I can see on the ISO REGEN circuit board it has no capability to block AC leakage loops.

 

 

 

My understanding of a $325 piece of gear in the 'sound improvement' category is it shouldn't be increasing mains noise by a whopping 20dB. 

[plissken]

4 minutes ago, lmitche said:

Scan and I have provided useful advice that would help Amir improve his testbed and objective evaluation of the ISO Regen based on real world experience.  

 

Ok, but he's testing the unit AS SOLD by Uptone. 

 

You have to take the good with the bad. It helped make a poor DAC better and it made an otherwise good DAC poorer.

 

So now additional money beyond the $325 HAS to be spent not to get the problems with the included SMPS. Makes you wonder how much validation, if any, was done.  Why even include a 3rd party SMPS when you have all the design chops in house to build a straightforward linear 5v .5 amp power supply. That would cost $10 in a BOM. 

[pkane2001]

1 hour ago, scan80269 said:

And I suggested yesterday that Amir replace the Mean Well SMPS with a battery to power the ISO REGEN and re-measure.  A purely scientific control experiment with only one component changed.

 

UpTone's LPS-1 power supply should also do the trick, but given Amir's obvious anti-UpTone stance, I thought a battery would at least be "neutral territory".  

 

Amir measured Behringer DAC while powering ISOR from his lab power supply. All the noise related to Meanwell PS went away, so I'm not sure why measuring with a battery or LPS-1 would prove  anything.

[MikeyFresh]

On 8/6/2017 at 9:44 PM, kumakuma said:

Sal, welcome back from the ASR ghost town! Out of curiosity I checked that place out and it looks like there's about ten active users and one new post every three hours in the forums. I don't think Alex needs to worry much about anything posted over there.  

 

Spot on, just about nobody one gives a sh*t about ASR.

[esldude]

2 minutes ago, MikeyFresh said:

 

Spot on, just about nobody one gives a sh*t about ASR.

Shouldn't that be spelled Sh**t.

[scan80269]

16 minutes ago, pkane2001 said:

Amir measured Behringer DAC while powering ISOR from his lab power supply. All the noise related to Meanwell PS went away, so I'm not sure why measuring with a battery or LPS-1 would prove  anything.

So Amir's own control experiment (replacing Mean Well SMPS with his lab power supply) should indicate the Mean Well is the culprit, and the ISO REGEN is merely susceptible to a power supply that can contribute to AC leakage.

 

The problem I see with an ISO REGEN that integrates the circuitry of an LPS-1 supply (or equivalent) is going to be a complete non-starter: way too expensive to improve an aspect of device performance that multiple folks have said is inaudible.  I certainly don't want to pay over $700 for such a device.  UpTone has essentially given customers an a la carte option: if you believe galvanically isolated USB regenerator is good enough for you its $325, but if you want the above plus AC leakage loop firewalling you can BYOB (bring your own battery) or buy the LPS-1 as a premium option.  I see nothing wrong with this.  No one said AC leakage loop firewalling comes for free.

 

[esldude]

5 minutes ago, scan80269 said:

So Amir's own control experiment (replacing Mean Well SMPS with his lab power supply) should indicate the Mean Well is the culprit, and the ISO REGEN is merely susceptible to a power supply that can contribute to AC leakage.

 

The problem I see with an ISO REGEN that integrates the circuitry of an LPS-1 supply (or equivalent) is going to be a complete non-starter: way too expensive to improve an aspect of device performance that multiple folks have said is inaudible.  I certainly don't want to pay over $700 for such a device.  UpTone has essentially given customers an a la carte option: if you believe galvanically isolated USB regenerator is good enough for you its $325, but if you want the above plus AC leakage loop firewalling you can BYOB (bring your own battery) or buy the LPS-1 as a premium option.  I see nothing wrong with this.  No one said AC leakage loop firewalling comes for free.

 

Well actually in the case of the iFi and the Behringer it does come free.  All the ISO switching supply issues vanished if you removed the ISO going to straight USB feed.  Sometimes simpler really is better.

[lmitche]

21 minutes ago, plissken said:

 

Ok, but he's testing the unit AS SOLD by Uptone. 

 

You have to take the good with the bad. It helped make a poor DAC better and it made an otherwise good DAC poorer.

 

So now additional money beyond the $325 HAS to be spent not to get the problems with the included SMPS. Makes you wonder how much validation, if any, was done.  Why even include a 3rd party SMPS when you have all the design chops in house to build a straightforward linear 5v .5 amp power supply. That would cost $10 in a BOM. 

One of our suggestions is to run his Macbook on battery and redo the test. That should cost nothing.

[scan80269]

9 minutes ago, esldude said:

Well actually in the case of the iFi and the Behringer it does come free.  All the ISO switching supply issues vanished if you removed the ISO going to straight USB feed.  Sometimes simpler really is better.

I recently did try simplifying one of my setups back to a direct USB link between PC and DAC.  Trouble is, the SQ worsened noticeably: elevated sibilance, grainier or harsher treble, etc.  So in this case simpler did not sound better.

 

[Speed Racer]

18 minutes ago, esldude said:

Well actually in the case of the iFi and the Behringer it does come free.  All the ISO switching supply issues vanished if you removed the ISO going to straight USB feed.  Sometimes simpler really is better.

 

...and here is the problem with just measuring. Sometimes what measures worse sounds better. Amir seems limited to just measuring which only part of the story. I would argue the least important part too. 

[pkane2001]

7 minutes ago, Speed Racer said:

Amir seems limited to just measuring which only part of the story. I would argue the least important part too. 

 

And what's the most important part? Sighted, unreliable, impossible to duplicate subjective listening?

[Speed Racer]

19 minutes ago, pkane2001 said:

 

And what's the most important part? Sighted, unreliable, impossible to duplicate subjective listening?

 

Well, for me, it's the sound I get out of my system. I have listened to plenty of great measuring audio gear that sounded completely boring and not at all engaging. Conversely, I have listened to great sounding gear that measured less well. Yeah, I look for gear that measures well. But, it's what it sounds like that matters in the end. Great specs don't really mean a whole lot ultimately. So, any test that focuses on specs or measurements without discussing sound is incomplete as far as I am concerned.

 

[bibo01]

If I can add a couple of words on this matter...

 

- Testing gear has to be electrically isolated, one cannot risk to couple with DUT.

- Testing with static signal is pretty pointless, most of all to draw conclusions on SQ. One has to use dynamic signal at DAC output and confirm results with actual music too.

- Following the above, I have shown measurements on original Regen where, depending on the DAC, Sound Quality was either improved or decreased. The DAC that was improved was not a $200 device - it was a $7000, well engineered device.  I am sure the same can be achieved with new IsoRegen.