ISO REGEN launch thread! (product web page up; photos, etc.)

[Horace28]

On 12/31/2017 at 8:41 AM, Superdad said:

 

Hi Horace:

Thank you for the follow-up.  Have you tried putting the red switch of the ISO REGEN in the up ('ON') position?  Does this cure your problem?  Let us know if it does and we can go from there.

You are also welcome to contact us directly--via the contract page on our web site.

 

Happy New Years to all!

 

--Alex C.

Yes, I have tried that setting, it doesn't change anything unfortunately.

[Superdad]

10 minutes ago, Horace28 said:

Yes, I have tried that setting, it doesn't change anything unfortunately.

 

Okay, then please write to us and we can see about exchanging your unit.  Perhaps you have an early one that displays that symptom in your system.

[Matias]

Will there be 5 LT3045s on an ISO Regen 1.2 as well?

[Superdad]

4 minutes ago, Matias said:

Will there be 5 LT3045s on an ISO Regen 1.2 as well?

 

Uh no. There are already 5 LT3042s on the ISO REGEN.  The only difference between the 3042 and the 3045 is the current capability (200mA for the 3042 and 500mA for the 3045), but none of the ISO REGEN circuits need anywhere near that much current.

[Matias]

I thought maybe the ISO Regen would also benefit from the lower noise of the regulator, but never mind. Thanks for answering.

[wakka992]

Hi guys,

 

I've just bought from a guy here in Italy a used UpTone Audio Iso Regen + UltraCap LPS-1 Power Supply combo.

He bought it in July 2017 directly from UpTone Audio.

He report that the unit works flawlessly but I vaguely remember I read somewhere there was a problem with the first batch (maybe? dunno, couldn't find an answer in the thread).

 

Am I making this up in my mind? XD

 

Looking forward to hear your ISO REGEN @Superdad

[Superdad]

7 hours ago, wakka992 said:

He report that the unit works flawlessly but I vaguely remember I read somewhere there was a problem with the first batch (maybe? dunno, couldn't find an answer in the thread).

 

Only a small percentage of units from the first run had issues.  If you get persistent tick sounds during the music, AND if they DO NOT go away by putting the red switch into the up ('ON') position, then contact us about replacement.

But if the seller reported it works "flawlessly" then it is unlikely you will be receiving a unit with the early issue.

 

ENJOY!  

[asdf1000]

Hi @JohnSwenson

 

If you get a spare moment can you share (at a high level) how these isolators like the Silanna chip used in the ISO REGEN actually work, i.e. how do they isolate the USB data lines? 

 

And is the USB ground of the ISO REGEN isolated by the Silanna chip or is that a different isolation method?

 

Asking these questions in another way, how does stuff actually get from one side of 'the moat' to the other side and how does this then block most of the (low impedance) leakage?

 

Cheers!

 

[asdf1000]

Found this nice high level explanation on digital isolators:

 

"Digital isolators use transformers or capacitors to magnetically or capacitively couple data across an isolation barrier, compared to optocouplers that use light from LEDs."

 

http://www.analog.com/en/technical-articles/anatomy-of-a-digital-isolator.html

 

My next question was why not use optical isolation (would this block both low AND high impedance leakage currents?) but that page goes into the disadvantages of opto-coupling too.

 

I'm also guessing it's isolating the ground connection that's trickiest?

 

 

[JohnSwenson]

15 hours ago, Em2016 said:

Hi @JohnSwenson

 

If you get a spare moment can you share (at a high level) how these isolators like the Silanna chip used in the ISO REGEN actually work, i.e. how do they isolate the USB data lines? 

 

And is the USB ground of the ISO REGEN isolated by the Silanna chip or is that a different isolation method?

 

Asking these questions in another way, how does stuff actually get from one side of 'the moat' to the other side and how does this then block most of the (low impedance) leakage?

 

Cheers!

 

The reason you use an isolator is that you want to isolate the ground. The ground is where the leakage current travels so it is the critical path to isolate. The problem is that without the ground connection normal signals will not pass, since they use the ground for return current. This is where the digital isolator comes into play, it transfers digital signals across a ground break.

 

There are many types of digital isolators, the most famous is the optocoupler, (LED pointing at photostransistor), there are many others: transformers, capacitively coupled, radio transmitters and my favorite, GMR (Giant MagnetoResistive).

 

There are two things that make high speed USB difficult:

1): high speed -- HS USB runs at 480 Megabit per second (Mbps), most digital isolators do not run anywhere near that fast. Some do, but they are not easy to come by and are very expensive.

 

2): HS USB is a bidirectional bus, all of the digital isolators are uni-directional, you need two, one for each direction. The hard part is that the isolators need to know which end is driving the bus, the isolator or what is at the other end. There is no wire in the bus that specifies which direction the data is going in at any given time. The ONLY way to do this is a full blown USB protocol engine that follows the commands on the bus and can thus figure out which direction the bus is going at any given time.

 

#2 is not easy, none of the big chip companies has a chip that does this, anybody that wants to to isolate HS mode has to do this themselves, very few companies have been successful at this.

 

Things get more complicated for capacitive and transformer coupled isolators. Neither of these transfers a steady state, they only transfer a CHANGE in signal. This means more complex encoding so they can handle the state of a signal not just that it changed. This limits the data rate they can handle.

 

I don't know for sure what the Sillana uses, but I think it is capacitively coupled.

 

That is the overview, if you want more detail, let me know.

 

John S.

[One and a half]

1 hour ago, JohnSwenson said:

The reason you use an isolator is that you want to isolate the ground. The ground is where the leakage current travels so it is the critical path to isolate. The problem is that without the ground connection normal signals will not pass, since they use the ground for return current. This is where the digital isolator comes into play, it transfers digital signals across a ground break.

 

There are many types of digital isolators, the most famous is the optocoupler, (LED pointing at photostransistor), there are many others: transformers, capacitively coupled, radio transmitters and my favorite, GMR (Giant MagnetoResistive).

 

There are two things that make high speed USB difficult:

1): high speed -- HS USB runs at 480 Megabit per second (Mbps), most digital isolators do not run anywhere near that fast. Some do, but they are not easy to come by and are very expensive.

 

2): HS USB is a bidirectional bus, all of the digital isolators are uni-directional, you need two, one for each direction. The hard part is that the isolators need to know which end is driving the bus, the isolator or what is at the other end. There is no wire in the bus that specifies which direction the data is going in at any given time. The ONLY way to do this is a full blown USB protocol engine that follows the commands on the bus and can thus figure out which direction the bus is going at any given time.

 

#2 is not easy, none of the big chip companies has a chip that does this, anybody that wants to to isolate HS mode has to do this themselves, very few companies have been successful at this.

 

Things get more complicated for capacitive and transformer coupled isolators. Neither of these transfers a steady state, they only transfer a CHANGE in signal. This means more complex encoding so they can handle the state of a signal not just that it changed. This limits the data rate they can handle.

 

I don't know for sure what the Sillana uses, but I think it is capacitively coupled.

 

That is the overview, if you want more detail, let me know.

 

John S.

Thanks John for the explanation.....but one thing, the ground reference, that's the 0V from the computer in the USB cable?

[asdf1000]

1 hour ago, JohnSwenson said:

That is the overview, if you want more detail, let me know.

 

John S.

 

Thanks John, no that’s more than enough for a high level. Cheers

[asdf1000]

12 hours ago, JohnSwenson said:

There are many types of digital isolators, the most famous is the optocoupler, (LED pointing at photostransistor), there are many others: transformers, capacitively coupled, radio transmitters and my favorite, GMR (Giant MagnetoResistive).

 

Hi John I will zoom in on your favourite there (GMR), if you don't mind.

 

Is there still capacitive coupling involved? Or is GMR as good as optical isolation (absolute zero leakage currents getting across)?

 

Have you played around with GMR isolation, especially with your new custom made leakage currents test gear?

 

[JohnSwenson]

9 hours ago, Em2016 said:

 

Hi John I will zoom in on your favourite there (GMR), if you don't mind.

 

Is there still capacitive coupling involved? Or is GMR as good as optical isolation (absolute zero leakage currents getting across)?

 

Have you played around with GMR isolation, especially with your new custom made leakage currents test gear?

 

GMR is magnetic, but is different than a transformer. A transformer passes change in a magnetic field, thus it cannot properly pass a steady high or low, just something changing. Thus all transformer based isolators have to send a more complicated series of changes to define a steady state signal.

 

GMR works differently, it has a coil that generates a magnetic field, and magnetically sensitive resistors. They change resistance with differing magnetic fields applied. Thus they inherently handle steady state signals as well as changing ones. They can run pretty fast, but are still fairly expensive.

 

The common optocouplers are fairly large and can't go very fast. The LPS-1 uses optocouplers all over the place to get signals between power domains. They work well for this because the signals are slow (32KHz) and the couplers are dirt cheap (40 cents per channel). GMRs are much faster (150MHz) but are much more expensive ($3 per channel). I use GMRs when I am isolating I2S signals.

 

Both optocouplers and GMRs have very low cpacitance, hence very good leakage isolation.

 

The problem with the ISO REGEN was not the isolation technology per se, but that for some reason the chip didn't work when there was a very rapidly changing voltage between the two sides. It turns out this can easily happen with older style SMPS supplies, particularly those used for residential networking equipment. Since most of you guys are using this with computer audio where residential networks are used, this happens a lot.  The only way to deal with this is to put a filter across the "moat" which slows down the edges, but also lets high impedance leakage through. In REALLY bad cases that isn't even enough which is what the switch is for.

 

John S.

 

 

[Jud]

That progression - from puzzling, intermittent phenomenon to hypotheses to measurement to conclusion to recommended solutions - was fascinating.

 

I understand it's just what you do, but it was great to read about it. 

[Superdad]

19 minutes ago, Jud said:

That progression - from puzzling, intermittent phenomenon to hypotheses to measurement to conclusion to recommended solutions - was fascinating.

 

I understand it's just what you do, but it was great to read about it. 

 

And great to see you back posting Jud!  Must mean that most of the boxes in your new house are unpacked, right?  

[Jud]

16 minutes ago, Superdad said:

 

And great to see you back posting Jud!  Must mean that most of the boxes in your new house are unpacked, right?  

 

Thanks! Yep, we are pretty much "open for business." (Although we're still sufficiently occupied with house stuff that I don't have quite the spare time I did before the move. And my old video card no longer works with Linux, not even the shell, so it will likely not be until I build a new machine that I run Linux and HQPlayer again.)

[asdf1000]

2 hours ago, JohnSwenson said:

The problem with the ISO REGEN was not the isolation technology per se, but that for some reason the chip didn't work when there was a very rapidly changing voltage between the two sides. It turns out this can easily happen with older style SMPS supplies, particularly those used for residential networking equipment. Since most of you guys are using this with computer audio where residential networks are used, this happens a lot.  The only way to deal with this is to put a filter across the "moat" which slows down the edges, but also lets high impedance leakage through. In REALLY bad cases that isn't even enough which is what the switch is for.

 

John S.

 

Hi John

 

Many thanks again.

 

I wasn't even hinting at the issues a small percentage of ISO REGEN users had with isolation switched on (as you say, you can still defeat the isolation and the sound is still fantastic as an Uber Regen).

 

But... I'm sure deep inside you'd preferred to have seen fewer issues with isolation and no need to have an isolation on/off switch (i.e. better reliability).

 

 

I had a very funky system setup (my fault) where I did have issues with the ISO REGEN isolation enabled. The iFi iGalvanic3.0 had the same issues. Something my Intona had no issues with.

 

I'm sure we'll see your favorite isolation method (GMR) pop up sooner or later. Hopefully sooner?

 

Even if it were in a bigger box , I'd love for something with the reliability of the Intona but better SQ

 

And something that did block BOTH high and low impedance leakage in the one box would be nice.

 

 

[Cornan]

46 minutes ago, Em2016 said:

 

I'm sure we'll see your favorite isolation method (GMR) pop up sooner or later. Hopefully sooner?

 

I have surely found my favorite USB isolation. ISO Regen>Luckit BluWave USB to Spdif. GI on. Isolation/floats/voltage regs in series is a true magic bullet in my (very) isolated setup. Seriesly! ?

[Superdad]

26 minutes ago, Em2016 said:

I wasn't even hinting at the issues a small percentage of ISO REGEN users had with isolation switched on (as you say, you can still defeat the isolation and the sound is still fantastic as an Uber Regen).

 

Yup.  

 

26 minutes ago, Em2016 said:

But... I'm sure deep inside you'd preferred to have seen fewer issues with isolation and no need to have an isolation on/off switch (i.e. better reliability).

 

You mean abandon the cursed Silanna isolator chip after all we went through to tame it? 

 

26 minutes ago, Em2016 said:

I had a very funky system setup (my fault) where I did have issues with the ISO REGEN isolation enabled. The iFi iGalvanic3.0 had the same issues. Something my Intona had no issues with.

 

I'm sure we'll see your favorite isolation method (GMR) pop up sooner or later. Hopefully sooner?

 

Even if it were in a bigger box , I'd love for something with the reliability of the Intona but better SQ

 

And something that did block BOTH high and low impedance leakage in the one box would be nice.

 

Addressing your last point first:

The current ISO REGEN already blocks passage--from input to output--of both high and low impedance leakage.

Of course the power supply used for the downstream/output side of the ISO REGEN ought not to be one introducing leakage, but that is a separate matter. 

 

As for doing a more advanced version:

Long ago--really during the development of the original USB REGEN in late-2014--John and I discussed including galvanic isolation and the fact that it would take using an FPGA (and no hub chip, and with a custom written or licensed high-speed USB hub core), two PHY chips, two power supplies (or transformer DC>DC arrangement to get one supply over the moat).

This was long before Intona even came on the scene with their FPGA-base isolator (which of course works well and reliably, but was never optimized for the audio chain; I won't critique it here, though I am sure my comments exist somewhere).

 

But complexity/design time, the success of the USB REGEN, other projects (UltraCap LPS-1!), and the fact that things were coming together for an über-REGEN (Crystek 575, LT3042s, really great USB3.1 hub chip), all lead to us taking a pass on a galvanically isolated REGEN.  Until Silanna announced their unique-in-all-the-world ICE08USB in October 2015.  We were the first audio company to contact them, and they were at first puzzled by our idea of using their chip in front of a USB hub.   We received samples (of their barely documented chip) at the beginning of January 2016, and the nightmare proceeded from there. 

 

Flash forward to now:

John and I have discussed (actually it was discussed more during some dark days when we thought ISO REGEN might never work right) a means of doing full isolation with just an FPGA, two PHY chips and a clock--without having to license a core (for USB hub protocol engine).  It could be done, but we have so many more interesting projects going on and I really think the market window for another USB device is closing.  It just would not sit right with me to tell everyone who just bought an ISO REGEN last year that we have something else to replace it.  Can't go to that well too many times.  Time to move on!

 

Ciao,

--Alex C.

 

[asdf1000]

4 minutes ago, Superdad said:

 It could be done, but we have so many more interesting projects going on and I really think the market window for another USB device is closing.  It just would not sit right with me to tell everyone who just bought an ISO REGEN last year that we have something else to replace it.  Can't go to that well too many times.  Time to move on!

 

Fair enough. I read that you're playing with a ZMan board (quite a few audio companies are at the moment) and like that they control/support the software side, so connecting the dots.... Looking forward to developments. Anyway I'm now off topic.

[str-1]

I posted this question also on the ‘Impressiins’ thread.  Can I safely run my ISO Regen off 5V?  My Chord DAVE dac only needs the 5V to be able to recognise a usb input.  Someone said the IR sounds better off 5V as that bypasses the internal regulators.  Would that be a good thing?

[tboooe]

2 minutes ago, str-1 said:

I pisted this question also on the ‘Impressiins’ thread.  Can I safely run my ISO Regen off 5V?  My Chord DAVE dac only needs the 5V to be able to recognise a usb input.  Someone said the IR sounds better off 5V as that bypasses the internal regulators.  Would that be a good thing?

Ive been running my IR off 5V for quite some time now.

[str-1]

3 minutes ago, tboooe said:

Ive been running my IR off 5V for quite some time now.

My technical knowledge is dangerously limited, but I thought that usually higher volts and lower amps (within allowable range) was usually better.  For example, with one of the IR’s rivals - the tX-USBultra - many users are saying the 12V version sounds best compared to the 9V and 6.5V-8V versions, with 9V the next best.

[Superdad]

20 minutes ago, str-1 said:

My technical knowledge is dangerously limited, but I thought that usually higher volts and lower amps (within allowable range) was usually better.  For example, with one of the IR’s rivals - the tX-USBultra - many users are saying the 12V version sounds best compared to the 9V and 6.5V-8V versions, with 9V the next best.

 

I just post an answer to your question over in the other thread (saw it there first).  As to the desire for higher voltage, such is not the case with the ISO REGEN at all.  Everything besides the 5VBUS regulator is set to 3.3V.  So high voltages in just get dumped as heat.

 

The SOtM product you refer to may have some DC-DC switching regulators in it.  That is the only time that higher voltage=lower amperage usage.