USB Ground Lift

[Superdad]

AFAIK no "normal" USB Hubs have USB B inputs...just with USB A plugs.

 

Sorry Cornan, I don't think that is correct. All USB hubs must connect their input to a USB host ('A' jack). So while a lot of them have a--typically short--captive input cable with a male 'A' plug to do so, all desktop USB hubs that do not have a captive cable have a female USB 'B' jack. Thus one uses a standard USB A>B cable to connect a hub to a computer. We of course adhered to that standard with the REGEN ('B' in, 'A' out), though for best signal integrity and impedance match we advise putting the hub (REGEN) as close to the DAC as possible.

 

Ciao,

 

--Alex C.

[Cornan]

Sorry Cornan, I don't think that is correct. All USB hubs must connect their input to a USB host ('A' jack). So while a lot of them have a--typically short--captive input cable with a male 'A' plug to do so, all desktop USB hubs that do not have a captive cable have a female USB 'B' jack. Thus one uses a standard USB A>B cable to connect a hub to a computer. We of course adhered to that standard with the REGEN ('B' in, 'A' out), though for best signal integrity and impedance match we advise putting the hub (REGEN) as close to the DAC as possible.

 

Ciao,

 

--Alex C.

Hi Alex!

Here is a Google search for "normal" USB hubs https://www.google.se/search?q=usb+hub&client=tablet-android-google&prmd=isvn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjJmcr21tXOAhUEDCwKHek1BLoQ_AUIBygB&biw=600&bih=960

Sorry, but I cannot find a single hub with female USB B jacks...just female USB A jacks and male A plugs.

:-)

 

My point with this was that Corning requires power via the USB B plug...and my guess is if a hub was used it was inserted to the A side of the Corning which will not work according to Corning's FAQ.

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[Superdad]

Sorry, but I cannot find a single hub with female USB B jacks...just female USB A jacks and male A plugs.

 

It is true that most hubs these days have captive input cords (with male 'A' plugs), but you will NEVER see the input of a hub be a female 'A' jack--those are for the devices only. Small hubs used to come with 'B' jack inputs until the captive-cord craze. Nowadays it is mostly just the hubs with quite a few ports that have an input jack.

 

Here are a few I found quickly on Amazon:

https://www.amazon.com/Rosewill-7-Port-Power-Adapter-RHUB-300/dp/B004F38VFO

https://www.amazon.com/AmazonBasics-Port-USB-Power-Adapter/dp/B00DQFGJR4

https://www.amazon.com/USB-Highspeed-Port-Adapter-Silver/dp/B002FFZGCU

[Cornan]

It is true that most hubs these days have captive input cords (with male 'A' plugs), but you will NEVER see the input of a hub be a female 'A' jack--those are for the devices only. Small hubs used to come with 'B' jack inputs until the captive-cord craze. Nowadays it is mostly just the hubs with quite a few ports that have an input jack.

 

Here are a few I found quickly on Amazon:

https://www.amazon.com/Rosewill-7-Port-Power-Adapter-RHUB-300/dp/B004F38VFO

https://www.amazon.com/AmazonBasics-Port-USB-Power-Adapter/dp/B00DQFGJR4

https://www.amazon.com/USB-Highspeed-Port-Adapter-Silver/dp/B002FFZGCU

Thanks Alex! I actually have'nt seen those around...but have'nt really looked them up either. This type of hub could work for the Corning...even if I personally would'nt use them in an audio chain. USB Regen is a much much better choise!

 

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[Al Jones]

Woke up this morning, took a deep breath and cut the external ground wire on my Elijah USB cable. The result - HOLY SHØT where did all that music come from!?!

 

The sonic upgrade is somewhere between adding the microrendu or adding the LPS-1 on top of the microrendu.

 

Total cost - two DC plugs to re-attach the ends of the cut ground wires, connected before handshake and disconnected afterwards.

 

Bad news is that with my DAC, I cannot disconnect 5V without losing signal, so there is no potential for going further down this path.

 

If you have easy access to the ground wire on your USB cable, you should try this.

 

Props to Cornan for tips and encouragement.

[ElviaCaprice]

In my system, I've eliminated the 5V vbus and shield in my Supra USB cable/adapter following my Intona. I run the ground outside the cable, so as to be able to connect or disconnect manually. I find no difference in SQ at all with the ground disconnected after handshake. There was an improvement in SQ eliminating the 5V vbus throughout the USB stream following the Intona.

[YashN]

In my system, I've eliminated the 5V vbus and shield in my Supra USB cable/adapter following my Intona. I run the ground outside the cable, so as to be able to connect or disconnect manually. I find no difference in SQ at all with the ground disconnected after handshake.

 

Well, wouldn't that be because the Intona itself already disconnects the GND?

[ElviaCaprice]

Well, wouldn't that be because the Intona itself already disconnects the GND?

 

You have to have the ground for handshake.

[Cornan]

Well, wouldn't that be because the Intona itself already disconnects the GND?

 

+1. However, benefits could be made if the modded Supra USB cable/adapter was BEFORE the intona instead of after. Also very important to make sure that the ground wire + shield to ground connection (if any) is properly removed.

[Cornan]

You have to have the ground for handshake.

 

That is why the GND have to be removable after the handshake is done. It have to have a switch or DC male+female plugs on the GND wire to work at all.

[ElviaCaprice]

+1. However, benefits could be made if the modded Supra USB cable/adapter was BEFORE the intona instead of after. Also very important to make sure that the ground wire + shield to ground connection (if any) is properly removed.

 

You don't need the modified Supra USB before the Intona, waste of cable. You still need 5V vbus to feed the Intona, I do it via LPS (soon LPS-1) to PPA V2 USB card to adapter to Intona.

[ElviaCaprice]

That is why the GND have to be removable after the handshake is done. It have to have a switch or DC male+female plugs on the GND wire to work at all.

 

Did you read my post???

I can disconnect the ground. It doesn't make one bit of difference in SQ disconnected or connected.

 

My theory: The Intona is doing it's job, I have galvanic isolation, no ground loop. All other components including DAC, 5V vbus (eliminated) and Regen are also properly isolated from introduction of any ground loops. Thus the disconnecting of the USB ground is unnecessary.

 

In fact, if you are hearing a difference when disconnecting the USB ground after handshake, you have a ground problem with one of your devices or 5V vbus.

[austinpop]

<snip>

My theory: The Intona is doing it's job, I have galvanic isolation, no ground loop.

 

<snip>

Indeed. That's great to hear.

 

Clearly, in USB tweak-world, there are many ways to skin a cat (break ground loops). Unlike lives, a cat only has one skin, so once skinned, you're done. Any further attempts, you're just flogging a dead horse.

 

Apologies for the horrible mixed metaphors. I don't know where they came from. I am normally very kind to animals.

 

But back to USB - since I have both Intona and the RUR, I too have wondered whether the whole ground lift experiment was moot.

 

Thanks for for the data point.

[Cornan]

Did you read my post???

I can disconnect the ground. It doesn't make one bit of difference in SQ disconnected or connected.

 

My theory: The Intona is doing it's job, I have galvanic isolation, no ground loop. All other components including DAC, 5V vbus (eliminated) and Regen are also properly isolated from introduction of any ground loops. Thus the disconnecting of the USB ground is unnecessary.

 

In fact, if you are hearing a difference when disconnecting the USB ground after handshake, you have a ground problem with one of your devices or 5V vbus.

 

I read it but did'nt get the impression that you actually connected & disconnected the GND. Sorry if I missunderstood.

As long as you have another USB cable with GND you will not hear the full potensial IMO. I am lifting the GND on all of my USB cables (plus no shielding) in the chain. All GND lifts makes a difference for the better...even if the first one gives the best SQ result. Intona will isolate the output no the next device..but you still need to mind about the other USB paths. Ground loops is not the only noise you have to care about. Grounds carry a lot of other noises. Anyway, I do not wish to start yet another GND lift or not discussion. It is all up to you if you are curious enough to give it a try. I am just showing you my side of the coin!

 

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[r_w]

With an Intona the effect is certainly more subtle as it does a lot of good work, probably the bass should be cleaner... GND lift throughout the entire chain however is something I'll never consider removing.

 

I would recommend making a new USB cable with balanced cable (twisted pair and braid) and GND lift switch, not modding an existing cable and make it as short as possible... then do the same throughout - unless of course your kit needs the +5V rail in which case you'll need battery or capacitor supply for everything to achieve total isolation.

 

As always YMMV... and of course if you're happy with it as it is, leave it be.

 

 

 

In my system, I've eliminated the 5V vbus and shield in my Supra USB cable/adapter following my Intona. I run the ground outside the cable, so as to be able to connect or disconnect manually. I find no difference in SQ at all with the ground disconnected after handshake. There was an improvement in SQ eliminating the 5V vbus throughout the USB stream following the Intona.

[r_w]

+1 ime

 

i read it but did'nt get the impression that you actually connected & disconnected the gnd. Sorry if i missunderstood.

As long as you have another usb cable with gnd you will not hear the full potensial imo. I am lifting the gnd on all of my usb cables (plus no shielding) in the chain. All gnd lifts makes a difference for the better...even if the first one gives the best sq result. Intona will isolate the output no the next device..but you still need to mind about the other usb paths. Ground loops is not the only noise you have to care about. Grounds carry a lot of other noises. Anyway, i do not wish to start yet another gnd lift or not discussion. It is all up to you if you are curious enough to give it a try. I am just showing you my side of the coin!

 

 

sent from my nexus 7 using computer audiophile mobile app

[r_w]

Good job... thumbs up!

 

Woke up this morning, took a deep breath and cut the external ground wire on my Elijah USB cable. The result - HOLY SHØT where did all that music come from!?!

 

The sonic upgrade is somewhere between adding the microrendu or adding the LPS-1 on top of the microrendu.

 

Total cost - two DC plugs to re-attach the ends of the cut ground wires, connected before handshake and disconnected afterwards.

 

Bad news is that with my DAC, I cannot disconnect 5V without losing signal, so there is no potential for going further down this path.

 

If you have easy access to the ground wire on your USB cable, you should try this.

 

Props to Cornan for tips and encouragement.

[Middy]

Sorry I can't give a real opinion on IFI'S I DEFENDER. My headphones went back to Mr Speakers for the flow upgrade the day i got the IFI ....... works nice as a port for battery 5v. Hard to say with thier iso lift and my hack 5v cable compare without any form of GND lift on mine.. ..

I will push to say yes better but no review for a while...3 weeks and 200 hours headphone burn in. + Need to make a manual 5v GND lift USB cable.....

Making it worse I just had a new electric meter fitted and a balanced isolation transformer coming...

Dam you Cornan .... you Svenske temptress....

 

 

Sent from my SM-G900F using Computer Audiophile mobile app

[ElviaCaprice]

It is all up to you if you are curious enough to give it a try.

 

I gave it a try, my only USB cable. Again there is no change in SQ with or without the ground in my system. Everything downstream of the Intona is battery operated, no Vbus. Thus no noise ground, moon gravity, solar flares. Agree everyone should try it for themselves. No need for any fancy switches. Is very simple to do. Cut the ground wire, remove shielding in immediate area to break any connection. Bare out both ends of ground, connect, pull apart to test.

[Cornan]

Sorry I can't give a real opinion on IFI'S I DEFENDER. My headphones went back to Mr Speakers for the flow upgrade the day i got the IFI ....... works nice as a port for battery 5v. Hard to say with thier iso lift and my hack 5v cable compare without any form of GND lift on mine.. ..

I will push to say yes better but no review for a while...3 weeks and 200 hours headphone burn in. + Need to make a manual 5v GND lift USB cable.....

Making it worse I just had a new electric meter fitted and a balanced isolation transformer coming...

Dam you Cornan .... you Svenske temptress....

 

 

Sent from my SM-G900F using Computer Audiophile mobile app

*Haha* there is a lot of temptations around this community!

I actually knew about the Isolation transformers a long time ago through @zilch0md when nobody else was discussing this matter. He described everything very clear and detailed (as he normally does). I just was'nt ready for the news at the time and honestly found those IT's ugly looking. If I would have taken his advice then I would most likely be in a better position now.

Temptations, knowledge and WAF needs to sync. I just needed some more temptation from JS and time to find a IT that had everything I'll need and was small enough to hide!

Well, money is always another disturbing factory's as well!

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[YashN]

Did you read my post???

I can disconnect the ground. It doesn't make one bit of difference in SQ disconnected or connected.

My theory: The Intona is doing it's job, I have galvanic isolation, no ground loop.

 

Which is what I said, right?

 

You're not hearing any difference because the Intona already is doing it and you're already hearing that - putting or removing another GND cable after it should be of no consequence.

 

It doesn't mean that disconnecting GND doesn't make an SQ difference in the usual case, on the contrary.

 

Still looking for a robust way of implementing this in my setup. GND disconnection does a great deal of good, as does a separate power to the DAC, even if it's yet another SMPS (I'm using an iPhone charger in the meantime, but a John Swenson-style Linear Regulated PSU is planned).

[zackthedog]

Woke up this morning, took a deep breath and cut the external ground wire on my Elijah USB cable. The result - HOLY SHØT where did all that music come from!?!

 

The sonic upgrade is somewhere between adding the microrendu or adding the LPS-1 on top of the microrendu.

 

Total cost - two DC plugs to re-attach the ends of the cut ground wires, connected before handshake and disconnected afterwards.

 

Bad news is that with my DAC, I cannot disconnect 5V without losing signal, so there is no potential for going further down this path.

 

If you have easy access to the ground wire on your USB cable, you should try this.

 

Props to Cornan for tips and encouragement.

 

I just received my Elijah cable. I like it very much. I actually prefer it with the ground connected. But I can hear a difference.

[YashN]

Bad news is that with my DAC, I cannot disconnect 5V without losing signal, so there is no potential for going further down this path.

 

That's what I thought as well with mine until I powered it completely externally. It works.

 

In the end though, I've had to reconnect GND because of other issues (like no sound on track format change), except I only reconnected with two circuits in, one for GND isolation and one for filtering the computer-side power. Sounds great, probably 85% or so of the fully disconnected GND.

 

My DAC now works externally powered.

[amir57bs]

On 7/25/2016 at 11:48 PM, JohnSwenson said:

This means that if you setup a computer feeding a DAC with a USB cable with all grounds cut and there is no other ground connections between them, the ground between those two systems will probably have around 50V between them. This means the DAC's USB chip is going to be seeing 50V on its pins, this is NOT a good thing!!!! The fact that a DAC still runs at all under these conditions is due to ESD protection circuits designed to protect against "static" discharges, unfortunately these circuits are only designed to be used for very short duration events, not continuous large DC offsets. They are protecting the USB receiver from being fried, but they will not continue to do so for a long time. Eventually they will fail and PFFT! your DAC goes up in smoke.

 

John S.

 

i just do that for 5 minutes and my berkeley alpha usb has no problem that times but after disconnecting and connecting again the berkeley never sounded like past.

now my berkeley works correctly but i have a sense that it's sound now is brighter , does it mean the lifted ground damaged my berkeley?

[marce]

On 7/26/2016 at 6:50 AM, Cornan said:

 

Thanks John!

For now I am leaning towards using this type of RF star router:

I will connect it with very low impedance wires to the chassi of all my devices (including Regen) and ground it to a Entreq Tellus grounding box. I will use unshielded 2-wire USB cables and XLR's between the devices.

My battery supplies (2pcs) will be grounded as well.

I will just send a pm to Entreq for further advices before I perform the "tweak". I'll need to make 100% sure that it will be safe before I make the switch.

 

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Entreq boxes are floating...