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ISO REGEN Listening Impressions (kicked off with some measurements)


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4 hours ago, Speedskater said:

Once again, you should not ground any double insulated component!

Or make any other connections to the chassis.

What is wrong with grounding the DC output of a double insulated power supply? The double insulation means it is essentially impossible for line voltage to connect to the output, how can grounding the output make that not true?

 

John S.

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2 hours ago, sdube said:

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.

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.

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1 hour ago, 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:

 

IMG_1561.thumb.JPG.7c08bcaa8ff6ec5a1f89c8abcd596106.JPG

 

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. :D

 

Didn't work for me.

 

But, well, I guess i'll just use it with the GI off, it sounds great anyway, until the end of the week I'll post my detailed impressions, but I can already say that I'm very happy with the iso regen.

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18 hours ago, sdube said:

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.

 

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 wire 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.

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12 hours ago, Cornan said:

+1 The sound with ISO Regens GI turned off is just sooo much better in my setup that with the GI turned on. I have no problem with this. I actually see it as a good sign! ? 

 

13 hours ago, sdube said:

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.

 

9 hours ago, Superdad said:

 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. :D

 

+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.

 

omq5uGzl.jpg

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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.

UptonedMacMini(onJS2)>TelluriumSiverDiamondUSB>IsREgen(onLPS1onJS2)>Curious(short)>BerkeleyAlphaUSB>TomboTronBNC>MetrumPavaneDAC>SilvermithPalladium>MargulesSF(20SE)Pre>TelluriumSilverDiamond>MarguesU280c(25SE)Amp>AZAbsoluteSpeakercables>MargulesOrpheus+MarguleSub.CD:Cambridge851C>StealthVaridigSextet>MetrumPavane.

Powerconditioning/cables:AudienceAR6TSSD;KubalaSosnaElationon>AR6;OndaRaptureonPre-andAmp;KaplancablesonDAC/Transport;Combak350>JS-2;AZAbsolute>Alpha USB.

5ab04fc775d4d_2018-02-1511_30_04.thumb.jpg.bdba2e1c8a8ba2d514247b298a41222d.jpg

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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.

 

UptonedMacMini(onJS2)>TelluriumSiverDiamondUSB>IsREgen(onLPS1onJS2)>Curious(short)>BerkeleyAlphaUSB>TomboTronBNC>MetrumPavaneDAC>SilvermithPalladium>MargulesSF(20SE)Pre>TelluriumSilverDiamond>MarguesU280c(25SE)Amp>AZAbsoluteSpeakercables>MargulesOrpheus+MarguleSub.CD:Cambridge851C>StealthVaridigSextet>MetrumPavane.

Powerconditioning/cables:AudienceAR6TSSD;KubalaSosnaElationon>AR6;OndaRaptureonPre-andAmp;KaplancablesonDAC/Transport;Combak350>JS-2;AZAbsolute>Alpha USB.

5ab04fc775d4d_2018-02-1511_30_04.thumb.jpg.bdba2e1c8a8ba2d514247b298a41222d.jpg

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15 hours ago, JohnSwenson said:

What is wrong with grounding the DC output of a double insulated power supply? The double insulation means it is essentially impossible for line voltage to connect to the output, how can grounding the output make that not true?

John S.

It's not about grounding an output. The output connects are safe.

It's about going inside a double insulated enclosure and grounding the chassis.

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1 hour ago, Speedskater said:

It's about going inside a double insulated enclosure and grounding the chassis.

 

I don't recall anybody suggesting that.

 

Simply finding a decent ground in the downstream side of the system and using the wedged wire trick above is about the easiest and safest method of dealing with this small problem that only occurs for a small number of users--for all the reasons already explained. 

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Hello!

 

Received my ISO Regen/LPS-1 bundle today and was of course eager to plug it in.

Had to restart and unplug some parts in the chain ( as usual ) then it popped on nicely.

 

I stuck it in between my sotm sms 200 Ultra and TX USB Ultra. I noticed an instant improvement in dynamics , warmth and a more 

realistic tone with also deeper bass. Very good sounding and it will get better as its burning in. Very pleased.

Thanks to Alex and John

 

Regards Magnus

Vinnie Rossi LIO integrated amp with DAC, Sotm SMS-200 ultra/TX USB ultra, powered by an Uptone LPS-1 Audiostore Roonserver powered by a  HD plex PS. ASUS router AC 68 powered by a Teddy pardo PS, 

Speakers are standmounts Klångedang T1 with external crossover , Rega Planar 3 Lejonklou Slipsik phonostage

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2 hours ago, Superdad said:

 

I don't recall anybody suggesting that.

Simply finding a decent ground in the downstream side of the system and using the wedged wire trick above is about the easiest and safest method of dealing with this small problem that only occurs for a small number of users--for all the reasons already explained. 

There is absolutely no need to ground the double insulated component. Just ground the component at the far end of the cable.

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23 hours ago, Speedskater said:

There is absolutely no need to ground the double insulated component. Just ground the component at the far end of the cable.

 

Basically, if one component of your audio system is connected to AC/safety ground then all interconnected components are technically grounded, including 'separate' power supplies. There is no technical or audiophile need to additionally ground anything and doing so may actually introduce a ground loop.

 

Note that this has nothing to do with Alex's suggestion to defeat possible galvanic isolation of a USB receiver in a DAC by connecting the chassis (USB bus) of the Iso Regen to the chassis of the DAC.

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Ok I just encountered a very weird grounding issue whilst playing w usb cables and the IR.


I seem to have lost any grounding contact with both my IR/LPS-1 and Hugo 2 except if my grounded ultrawide monitor's DP cable is connected to my laptop.

 

It's utterly bizarre, all I need to do is to simply unplug the DP cable and then I'd feel this buzzing vibration on the aluminum surface of both my IR and Hugo 2. Plug the DP cable back in, and suddenly both devices become grounded.

 

My laptop, ultrawide monitor, IR/IPS-1, Hugo 2 are all plugged into the same PS unit that is also grounded (3 pin grounded plug). 


I've tried plugging the IR/LPS-1 in different wall sockets but I can't seem to get proper grounding anymore. Same for the Hugo 2. Both seem to have lost their grounding properties. 

 

Can anyone please explain what exactly is happening and why? I really do not want to depend on the ultrawide monitor to properly ground all my devices.

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26 minutes ago, Audiophile Neuroscience said:

Now, I am not attributing all of this to the ISOREGEN/LPS1/USPCB. In fairness it has come at the end of a long list of amazing other products and treatments. I will say it has pulled its weight in an otherwise very high-end system. For the dollar value, it is punching well above its weight, a knockout.

 

Congrats to Mr Swenson and Mr Crespi.

 

Very nice David, thank you.  For some further grinning and good feelings, now go play that entire Ryan Smith mastered Nina Simone SACD I sent you!  :D

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1 hour ago, Superdad said:

Very nice David, thank you.  For some further grinning and good feelings, now go play that entire Ryan Smith mastered Nina Simone SACD I sent you!  :D

 

Hi Alex,

Grinning indeed. You know how I love to find these old gems! Thank you so much!! Nina's debut amazing pianist and vocals from 1957, great sound. It threw me at first with stereo rhythm section seemingly, then vocals from left speaker and more piano from right.  At least I hope this is the way it was mastered from the original mono...lol.

Thank you

David

Sound Minds Mind Sound

 

 

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On 06/09/2017 at 8:26 PM, magnuska said:

Hello!

 

Received my ISO Regen/LPS-1 bundle today and was of course eager to plug it in.

Had to restart and unplug some parts in the chain ( as usual ) then it popped on nicely.

 

I stuck it in between my sotm sms 200 Ultra and TX USB Ultra. I noticed an instant improvement in dynamics , warmth and a more 

realistic tone with also deeper bass. Very good sounding and it will get better as its burning in. Very pleased.

Thanks to Alex and John

 

Regards Magnus

Hey Magnus (or anyone else who can make similar comparisons)

would you care to give us a quick summary of how these great bits of kit compare?

If you could only have one, which would it be and why?

Plus, I would assume the ISO Regen has the best bang for its buck, but please correct me if I'm off base. 

 

I have been 'out of the game' for many moons. I'm like a dinasaur with my amber Regen. I take it nobody uses it any of these more advanced setups?

Synology NAS DS216SE + TF cards -> GentooPlayer in RAM on mini fanless/supercap NUC -> Audio GD R-27 -> S.A.T. Infinity monoblocks -> Gallo Stradas + TR-3 sub Hifiman HE560

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Iso and LPS received today, plugged them in between Ultrarendu/Lush and DAC using the uspcb. Sound is not very good compared to Ultra straight into the DAC. Ultra is fed by Sonore Signature so this might explain the experienced degradation. I will burn in Iso/LPS in my office system and give them an other try in a week or so.

Synology 916+/Tidal --> fiber --> Er --> HDplex lps powered 6700K with JCAT NET running HQPe on Euphony—> Pink Faun Ultra OCXO I2s--> Pink Faun DAC 2.32 (32 x PCM1795 & dual power supplies)--> Ayre AX5 --> Paradigm S8 (Nordost SPM & TYR cables)

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What did you power the LPS-1 with?

mb pro>ethernet / elgar iso tran(2.5kVa, .0005pfd)>consonance pw-3 boards>ghent ethernet(et linkway cat8 jssg360)>etherRegen B-side(js-2)>ghent ethernet(et linkway cat8 jssg360) >ultraRendu A-side(clones lpsu split>lps1.2)>uspbc>iso regen(clones lpsu split>lps1.2)>curious regen link>rme adi-2 dac(js-2)>cawsey cables>naquadria sp2 passive pre> 1.naquadria lucien mkII.5 power>elac fs249be + elac 4pi plus.2> 2.perreaux9000b(mods)>2xnaq12” passive subs.

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9 hours ago, jamesg11 said:

What did you power the LPS-1 with?

Mean Well connected to a different power strip and outlet than the rest of the system.

Synology 916+/Tidal --> fiber --> Er --> HDplex lps powered 6700K with JCAT NET running HQPe on Euphony—> Pink Faun Ultra OCXO I2s--> Pink Faun DAC 2.32 (32 x PCM1795 & dual power supplies)--> Ayre AX5 --> Paradigm S8 (Nordost SPM & TYR cables)

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18 hours ago, odelay said:

Hey Magnus (or anyone else who can make similar comparisons)

would you care to give us a quick summary of how these great bits of kit compare?

If you could only have one, which would it be and why?

Plus, I would assume the ISO Regen has the best bang for its buck, but please correct me if I'm off base. 

 

I have been 'out of the game' for many moons. I'm like a dinasaur with my amber Regen. I take it nobody uses it any of these more advanced setups?

 

Hi Odelay,

 

I have not tried only the ISO Regen with DAC as this combo really works fine together with my  soTm chain I use but If I would choose I suspect that ISO Regen /LPS 1 is hard to beat SQ wise and also great bang for its buck:D

 

 

Vinnie Rossi LIO integrated amp with DAC, Sotm SMS-200 ultra/TX USB ultra, powered by an Uptone LPS-1 Audiostore Roonserver powered by a  HD plex PS. ASUS router AC 68 powered by a Teddy pardo PS, 

Speakers are standmounts Klångedang T1 with external crossover , Rega Planar 3 Lejonklou Slipsik phonostage

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4 hours ago, magnuska said:

 

Hi Odelay,

 

I have not tried only the ISO Regen with DAC as this combo really works fine together with my  soTm chain I use but If I would choose I suspect that ISO Regen /LPS 1 is hard to beat SQ wise and also great bang for its buck:D

 

 

thanks Magnus - I appreciate it. 

Life is way too short to test every permutation. 

Enjoy the music ?

Synology NAS DS216SE + TF cards -> GentooPlayer in RAM on mini fanless/supercap NUC -> Audio GD R-27 -> S.A.T. Infinity monoblocks -> Gallo Stradas + TR-3 sub Hifiman HE560

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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:

 

IMG_1561.thumb.JPG.7c08bcaa8ff6ec5a1f89c8abcd596106.JPG

 

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. :D

 

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.

 

UptonedMacMini(onJS2)>TelluriumSiverDiamondUSB>IsREgen(onLPS1onJS2)>Curious(short)>BerkeleyAlphaUSB>TomboTronBNC>MetrumPavaneDAC>SilvermithPalladium>MargulesSF(20SE)Pre>TelluriumSilverDiamond>MarguesU280c(25SE)Amp>AZAbsoluteSpeakercables>MargulesOrpheus+MarguleSub.CD:Cambridge851C>StealthVaridigSextet>MetrumPavane.

Powerconditioning/cables:AudienceAR6TSSD;KubalaSosnaElationon>AR6;OndaRaptureonPre-andAmp;KaplancablesonDAC/Transport;Combak350>JS-2;AZAbsolute>Alpha USB.

5ab04fc775d4d_2018-02-1511_30_04.thumb.jpg.bdba2e1c8a8ba2d514247b298a41222d.jpg

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