ISO REGEN Listening Impressions (kicked off with some measurements)

[sdube]

Well, my first Iso Regen was one of the few that didn't meet the QC, and the mismatch with Berkeley Alpha USB was a disaster. After the failed experiment I removed the two previous (Amber) Regens to go directly from the Mac Mini to the Alpha USB, finding the sound to be more direct, crisp, yet relaxed. Meanwhile, Alex very kindly sent along a second ISO Regen, bearing the priority postage cost himself (I covered the difference for moving up to Fedex).

The sound is, in a word, fantastic. And I have very few hours on it yet. Alas, travel for several weeks at end of month, but shall come back and write in greater detail about what I find captivating about the music as well as sound. 

Two points/queries: 1. There are occasional dropouts, but there is no need to reset anything, just return to Audirvana again: Is this because of the implementation of the ISO Regen? 2. At what voltage should I have the second rail of the JS-2 feed the LPS-1 that powers the Iso Regen? At the moment, it is 9 V, would going down to 7V have any advantages. 

At any rate, thanks so much Alex and John.

[sdube]

Thanks so much, Alex. Yes, it is a Mac Mini, Uptoned and all.

 

[sdube]

Well, it was one of the few faulty IRs, and there was crackling noise and nothing-but data-dropouts on the Alpha USB. But with a new IR, all is working splendidly.

[sdube]

16 hours ago, rickca said:

What was the nature of the problem?  I have a Berkeley Alpha USB and it worked fine with the original REGEN.  Is there something about the ISO REGEN that makes the combination more problematic?

Well, it was one of the few faulty IRs, and there was crackling noise and nothing-but data-dropouts on the Alpha USB. But with a new IR, all is working splendidly.

[sdube]

On 9/2/2017 at 6:01 PM, kalinka said:

Listened to the Iso Regen the whole day today, with the galvanic isolation defeated. It's the only way to not have any dropouts.

 

Well, I'm liking it even without the galvanic isolation feature. Tomorrow I'll listen to it a bit more, then I'll give my impressions.

I have been in touch about this issue with Superdad/Alex. He suggested that I switch off the Galvanic Isolation on IR, and I did that today. I have no dropout now. But also the music is sounding clearer and more compelling. Is this possible? As my signature line below would show I go from the UpToned Mac Mini on Js-2 over a LH Labs Lightspeed 10 G USB (change from Curious USB) cable to an LPS-1 (also on JS-2) onto the IR thence through the new hard adapter to  Berkeley Alpha USB to a Metrum Pavane DAC.  What might be the reason for the sound/music being clearer? Am I dreaming things? Clearly, my gear is grounded: Do I need to ground something upstream, and how, in order to get benefits of Galvanic Isolation? A bit confused. Please help.

[sdube]

16 hours ago, sdube said:

I have been in touch about this issue with Superdad/Alex. He suggested that I switch off the Galvanic Isolation on IR, and I did that today. I have no dropout now. But also the music is sounding clearer and more compelling. Is this possible? As my signature line below would show I go from the UpToned Mac Mini on Js-2 over a LH Labs Lightspeed 10 G USB (change from Curious USB) cable to an LPS-1 (also on JS-2) onto the IR thence through the new hard adapter to  Berkeley Alpha USB to a Metrum Pavane DAC.  What might be the reason for the sound/music being clearer? Am I dreaming things? Clearly, my gear is grounded: Do I need to ground something upstream, and how, in order to get benefits of Galvanic Isolation? A bit confused. Please help.

My stuff all is ground(ed). Yet, the skitish-ness of Berkeley Alpha USB goes away only when the Galvanic Isolation (GI) is turned off. What should I do to defeat this problem and have the GI on? The music is great without the GI though.

[sdube]

14 hours ago, JohnSwenson said:

This is all dependant on where leakage and static can be going. The only for us to know is for you to post a diagram of your system. Include all the equipment including computers that are connected to the audio system. Include the signal connections AND the power connections for each device. Include if a power connection is 2 pin or 3 pin. Include what the power connections are plugged into, such as all on the same power strip, two power strips plugged into the same duplex outlet etc. Also include any power "conditioners/filters" in the system. If a component has a separate PS box include that as well.

 

Include if the DAC has internal isolation between USB receiver and the rest.

 

From this info we can make a stab at figuring out what is going where. Unfortunately this is very system dependent, there is no way to make generalizations since every system is different.

 

John S.

Thank you John. Given my abilities, I would need help to draw the diagram you are suggesting. (We are all challenged in different ways, I reckon.) In the meanwhile, I shall follow Alex's suggestion to ground the floating USB input of the Berkeley Alpha USB. If that works, great; otherwise, onwards to the diagram.

[sdube]

7 hours ago, Superdad said:

 

I would be helpful to know if you have yet tried my specific suggestion of grounding your Berkeley Alpha's floating USB input stage with a wide from either of the downstream shells connecting the ISO REGEN to the Berkeley.  Does that allow you to turn the ISO REGEN's isolation back on?  It should--as I think it did for another Berkeley Alpha user.

Thanks, Alex: 1. How do I ground the Berkley Alpha's floating USB? Apologies, but I don't understand "...with a wide from either of the downstream shells connecting the ISO REGEN to the Berkeley." (With my addled competence for matters technical [even mildly so], I have to be walked slowly through any such procedure.) 2. What do you think is making the music sound better with the Galvanic Isolation turned off in my system -- just curious? 3. I will be placing an order soon for another USPCB A>B Adapter to connect the Mac Mini via that to the Iso Regen, dispensing with the LH Labs Lightespeed 10 (that replaced the Curious USB there): trust that it would reach Chicago by 25 September or so? Thanks again in anticipation of your responses.

 

[sdube]

On 9/5/2017 at 7:35 PM, Superdad said:

Hi Gents:

 

Back from my 4-day holiday weekend trip (mostly unplugged!) and am just now looking at the forum--while hacking away at the mountain of e-mails in my inbox (it will take about half of every day this week to reply to all of them so please be patient).

 

Let's talk about DOWNSTREAM GROUNDING:

a) Not everyone this issue.  Most people can use the ISO REGEN with its full galvanic isolation. [Switch in the down ('1') ISO position.]

 

b) The issue is not unique to the ISO REGEN.  It is byproduct of the way the Silanna isolator chip works. 

The iFi Audio nano iGalvanic also has a switch.  [I suspect that folks have to use their switch more often; I have a Singxer SU-1 (powered by a separate UltraCap LPS-1), and while I can use the ISO REGEN with isolation on, with the iGalvanic I have to flip the switch to avoid bad ticks and static.  Funny, they went for a second hub chip--in front of the Silanna--yet that does not help. (we found that out 10 months ago).]

 

c) We believe the issue occurs because, with full isolation, EMI--in the air and from charges built up on the cables and around the casework--have no easy path to "drain" to.  The charges build up (I think on the upstream side of the Silanna chip), and then discharge--right into the data stream coming out of the isolator chip.  Those are passed along to the hub chip and to the DAC so you hear them.

I bet that, like me, a lot of people find the problem to vary based on humidity in the room (dry days, air conditioning, etc.).

 

d) If the ground of the downstream side is isolated, then why the heck do charges on the upstream get through, and why does improving grounding on the downstream side often help?  To be completely honest, I have no idea.  John's lab was packed up after the ISO REGEN design was finalized, and I then discovered a few cases where better grounding was needed.  So we added the switch to be safe and as a diagnostic tool.  Now that his new lab is set up, maybe he can probe around to better understand what really goes on.

 

e) Other than for folks feeding bus- or battery-powered DACs/headphone amps which are not further connected to any system ground--typically via the cables to a preamp--the problem seems to be most prevalent for those whose DACs' (or USB>S/PDIF converters') USB inputs are themselves somewhat isolated.  That is, many DACs/DDCs use digital isolators--they are ALWAYS AFTER the USB input PHY/processor, on the I2S lines (hence improved signal integrity/impedance match from our REGENs or other similar hub-based devices still have their effect).

In order to make best use of their digital isolator chips, many (maybe most) DAC/DDC designers will elect to bus-power their entire USB input stage.  This allows them to leave the entire USB input stage ground plane common to that of the source (computer, etc.)--and not shared with the ground of the rest of the DAC/DDC.  It is the easiest way to fully utilize their digital isolators--unless they provide a 100% separate power supply (back to a separate winding on the power trans, or even a separate trans) or jump through some other hoops to provide power from a separate ground domain.

 

f) So considering "e)" above, it is easy to see that often what really needs additional grounding help is the DAC/DDC USB input stage--and not necessarily the DAC itself.  Now think about the downstream/output side of the ISO REGEN: its grounds (the entire "clean side" of the device, pin 4 of the USB jack, and the shield) are common only to whatever power supply is used for it AND the DAC/DDC USB input.  And if the PS used for the ISO REGEN is a "floating" type like the LPS-1 or a battery--then the entire downstream ISO REGEN/DAC USB input lacks any real ground reference!  (BTW, the Berkeley Alpha and Singxer SU-1 are two popular examples of DDCs whose inputs are entirely bus-powered--and thus quite susceptible to the above.  Of course they also benefit from both of the ISO REGENs other prime functions--improved signal integrity/impedance match and very clean USB 5VBUS power.)

 

g) My recommendation--and it has already worked for a bunch of folks--is not to bother with better grounding for the DAC itself (and a number of you have noted that your DAC's main PS is already grounded and/or the analog cables are grounding it to the rest of your system).  Rather you should simply ground the DAC's/DDC's USB input.  Of course that happens to be common to the output ground shell of the ISO REGEN, as well as your USB cable or USPCB A>B Adapter.  So here is a pic of the easy fix:

 

 

What you see is simply a stranded 18AWG wire, stripped about 5mm, placed on top of the USB 'A' plug, and inserted into the ISO REGEN at the same time.  If you get it in right, it will hold nice and tight.  This is the easiest place to attach this ground wire as you can do it on your desk before plugging things into the back of your DAC.

Then attach the other end of the wire to any other downstream ground--a screw on your DAC or preamp would be fine--assuming that component is grounded to your AC mains.  Or you could run the wire to a wall plug ground.

 

h) The above is likely to partially defeat the digital isolators that may be inside your DAC/DDC--between the USB stage and I2S lines to the rest of its circuitry.  But they will still be somewhat effective (on the data lines) and then you should be able to utilize the ISO REGEN with its switch in the down, fully isolated position.  Remember, digital isolators after a DAC/DCC's USB input are mostly to isolate from the computer (as well as the dirty 5VBUS that the USB input then must necessarily use)--and the ISO REGEN takes care of that!

 

Lastly, we have always emphasized that the ISO REGEN is about far more than just its galvanic isolation feature.  The best clock, the best USB 3.1 hub chip, the best ultra-ultra-low-noise regulators, and the greatest attention to detail paid by John to layout and layers--all right at the input of your DAC (preserved by the near-perfect USPCB A>B Adapter).  For those whose DAC/DDC has some galvanic isolation built in, it might be a toss-up as to which GI will sound better--that from the ISO REGEN or from the converter.  If you can utilize both without static ticks great.  Otherwise you can flip the switch up ('ON'/defeat) and still greatly enjoy the prime benefits of the ISO REGEN just as an über-REGEN. 

 

Just followed Alex's advice and grounded the ISO Regen through my Pre-Amp (separate) Power Supply, thus defeating the floating ground of the Berkeley Alpha USB, and turned on the Isolation switch of the IR (by bringing it down to Iso position): no dropouts in the last two hours, but even more the music is incredible, the sound is super. Thank you so much, John and Alex, including walking me through the procedure.

 

[sdube]

On 9/6/2017 at 3:22 AM, Ciukas said:

+1 also but I suppose every DAC will vary of course. Also I have the LPS-1 powering the IR so I dont know how the IR would sound w a standard power supply. Tbh I couldnt really tell any difference w the galvanic isolation turned off w the Hugo 2. All the benefits the ISO Regen brings to my tracks, greater dynamics, more presence, etc are still there... but that could also be bc Rob Watts made sure the lack of galvanic iso wouldnt be an issue w the H2.

 

Grounding the ISO R -- to defeat the Berkeley Alpha floating USB ground -- and turning on the Galvanic Isolation has given me an incredible boost in sound- and music-quality.

[sdube]

After all the exchanges here, let me come in as something of a dissenter. I  found that using the Ifi USB 3 and the Amber Regen -- all on JS-2, the latter on LPS-1 -- before the Iso Regen (on an LPS-1 on JS-2), didn't help anyway. Going the most direct way has been the best. Here, the sound was better -- and there were no drops -- with ISO off given the proclivities of my Berkeley Alpha USB. However, following Alex's advice, grounding the ISO R -- to defeat the Berkeley Alpha floating USB ground -- and turning on the Galvanic Isolation has provided an incredible boost in sound- and music-quality. The changes to my system in the signature line are the use of an LH Lightspeed 10 instead of the Curious USB, the former sounding way better. And I am soon going to replace this with the UPSCB A>B -- staying away from the Tellurium Silver Diamond USB that I had considered before finding out the reasons why it has been discontinued -- going from Mac Mini into ISo Regen going into another UPSCB A>B into the Berkeley Alpha USB and onwards. Doubt if I have the time or desire to monkey any further with  Ifi USB 3 and/or the Amber Regen after/before the Berkeley. The Ifi USB 3 and Amber Regen are comfortably ensconced in my desk system. On the regular rig, I am transported by the music, especially in the wake of the dreadful earthquake in Mexico City. Now, can someone please tell me how to edit my signature line?

[sdube]

Well, happy to say, I have no pops, crackles, or cackles after grounding the ISO Regen before the Alpha USB.

 

[sdube]

5 minutes ago, fsmithjack said:

How do you ground the ISO Regen? 

 

Grounded the ISO Regen through to my Pre-Amp (separate) Power Supply, thus defeating the floating ground of the Berkeley Alpha USB, and turned on the Isolation switch of the IR: no dropouts, pops, crackles, but even more the music is incredible, the sound is super. Alex/Superdad provided instructions earlier in this post/exchange.

[sdube]

1 hour ago, Cornan said:

 

I thought an update would be in order. 

After trying the DC negative grounding on my three floating SMPSs (grounded to a Entreq Minimus Grounding box which sounded better than grounded to the powerstrip) two amazing things happened in my setup:

 

1. Now suddenly the ISO Regen sounds wonderful with galvanic isolation on using a Vertere D-Fi Pulse V2 USB cable between Auralic Aries Mini and ISO Regen and USPCB between ISO Regen and Brooklyn DAC. No need to use my Regen Amber pre the ISO Regen anymore.

 

2. I use to ground the chassi of my AQVOX switch-8. After the DC negative grounding that improvement was not at all as important anymore. However, I will need to run additional test to confirm if the need is just reduced or actually removed all together.

 

Anyway, I hope this could help others. A big hug to @JohnSwenson for suggesting this simple and very effective tweak!

 

As I have stated/indicated, again and again, grounding the ISO Regen -- to defeat the floating ground of an expensive component in my set-up -- and turning on the GI yielded/yields remarkable results.

 

[sdube]

So, I have run into a hitch. I replaced my USB cable with a USPCB Adapter from the Mac Mini to the Iso Regen (and another USPCB Adapter goes into the Berkeley Alpha USB thingamajig). I retained the grounding procedure on the second  USPCB Adapter into the PSU of my Preamp, as Alex C had suggested. But I am getting dropouts again with this configuration. Switching the Galvanic Isolation off removes the dropouts, and also improves the sound. Is there something wrong with grounding procedure, since the wires on the Iso Regen/USPCB Adapte are a bit scattered now? Or, am I missing something? Please help.

[sdube]

6 minutes ago, Cornan said:

 

Do you use the grounding proceedure on several SMPS at the same time? I got a similar issue with my ISO Regen that was resolved by grounding the SMPSs for the network devices (Aries Mini & Aqvox switch) to a grounding box and the SMPS to the ISO Regen to a star-earth plug on my PSD.

If you ground several devices try to remove the DC- output grounding to the ISO Regen. If it improves find another spot to ground it to.

Thank you: I (tried to) ground only one. I should be more explicit, but my signature line (to be amended) assumes a bit.

[sdube]

7 minutes ago, Cornan said:

 

Your welcome! ? If it is only one it should be grounded to the same spot as the SMPS is plugged into. Be aware that you might create a ground loop path if ground it elsewhere.

Thank you for this. I am sorry, but there is no SMPS involved: do look up my signature line.

[sdube]

21 minutes ago, Frojo said:

Possibly counter intuitive, but i would remove the JS2 feed to the  LPS1/IsoRegen and use its meanwell.

 

Thanks so much. Earlier the JS-2 worked though, but  I am stupid.

[sdube]

Back after a few months away, including ten weeks in India. In October, before leaving, I connected the Mac Mini via a (new, properly oriented) USPCB A>B Adapter -- instead of the LH Labs Lightspeed USB -- into the ISO Regen and then via another USPCB A>B Adapter into the Berkeley Alpha USB. The ISO switch remained on. The dropouts that had disappeared after the grounding trick suggested by Alex reappeared with the inclusion of the first USPCB A>B Adapter. I removed the grounding wire and turned off the isolation switch, and again problems disappeared. I have just now turned  the ISO switch on again, without the grounding: it has been some hours and no dropouts yet. Fingers crossed and shall keep you informed, but what gives?

 

[sdube]

On 2/18/2018 at 1:37 PM, Superdad said:

 

Hi Saurabh:

 

At this point, for your system, I really do not have any idea what is causing the variabilities you have been reporting.  We know it is not your sample of ISO REGEN, as we replaced it for you many months ago.

Something in your system--or even with other appliances and lighting on your electrical system--may have changed.  It is known that the Berkeley Alpha UBS>S/PDIF--with its floating/bus-powered USB input--is rather sensitive to even the slightest signaling disturbances.

 

Full galvanic isolation with USB can be a tricky thing.  So at this point, for your system, if the problem comes up again, you may have to live with using the ISO REGEN with the isolation defeated.  That aspect of the device still accounts for only about 15-20% of its overall "greatness" in my opinion.

 

Do keep us posted though. (And maybe look around at your system and household devices.  I seem to recall you saying that in your location you have some general power problems.)

 

Best,

--Alex C.

Thanks so much, Alex. Well, one of the changes is the Mac Mini connected via USPCB A>B Adapter -- instead of the Curious/LH Labs Lightspeed USB cable - into the ISO Regen. (The second USPCB A>B Adapter from the ISO R to the Berkeley Alpha USB was already there.) Whatever, with Isolation turned sound is super and no glitches for (almost) a week now. Fingers still crossed, but the sound from my new Margules Orpheus (ceramic driver speakers) is brilliant. Photo attached

[sdube]

2 hours ago, Superdad said:

 

Nice set-up Saurabh!   

Very glad to know that things are working well for you.

--Alex C. 

Thanks so much, Alex. As I have mentioned, I write with music playing, so that is going well, too. (Touch wood.) I will send a question your way on email about the new LPS.

[sdube]

On 2/24/2018 at 4:28 PM, Superdad said:

 

Nice set-up Saurabh!   

Very glad to know that things are working well for you.

--Alex C. 

Golly, the drop-outs came back after I switched the amplifier onto its separate, dedicated circuit (itself occasioned by the Audience Power Conditioner tripping again and again):  first I switched the isolation off of course, but since this morning have it back on again: only two failures in over an hour. Might try the grounding trick again. (And as discussed about to send you a message, too, Alex.)

 

[sdube]

1 hour ago, Superdad said:

 

Saurabh:  Given all the various electrical issues you seem to have had at your location (power conditioner tripping?) over the years, and the sensitivity  of your Berkeley Alpha USB (if I recall), I am not sure that reliably running the ISO REGEN with full galvanic isolation will ever be possible for you.  Very sorry about that, but you can still enjoy its benefits as an über-REGEN. 

Thanks again, Alex. The power conditioner was not really tripping: just switching off; likely, it was the amp drawing too much current, since after plugging the latter into a separate circuit, there have been no problems there. The GI did function once, with your grinding trick, but then started misbehaving after I put a second hard-adapter from the ISO Regen to the Berkeley Alpha USB. Later, without the grounding, the GI functioned again, till the latest changes. And so, I am going to try the grounding measure again, but need someone with skills to do it: I am clunky and clumsy!

[sdube]

37 minutes ago, rickca said:

Have you ever tried running without your Audience unit plugged in?  Just as an experiment?

Thanks: I could get the JS-2 that feeds my Mac Mini and the LPS-1 off the Audience. Is that what you meant? Not possible to get the Audience out completely, 'fraid.

[sdube]

1 hour ago, rickca said:

If the LPS-1 plugged into the Audience is powering your ISO REGEN, it may be worth a try.  But I was suggesting running without the Audience altogether just to see how that might affect your dropouts.  I suspected that would not be possible.  I don't mean to say anything bad about Audience, this is just troubleshooting.

Thanks again. I have the JS-2 -- that feeds the LPS-1 (into the Iso-Regen) as well as my Mac Mini -- plugged into the Audience. Alex was agnostic about the effect of the Audience on the JS 2. And I may try getting it off the Audience. But, for the moment, I have managed to ground the Iso-Regen. Pleased as punch, and proud too. Music is much more compelling, which leads me to think (finger's crossed, several times) that the drop-outs will stop. The thing is that with Iso_Regen on GI without grounding the problem is not just with the drop-outs, but that the SQ declines.