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JDS Synapse & Neutron V1 USB Isolators Review

Rate these USB Isolators:

  • 1. Poor (headless panther)

    Votes: 0 0.0%
  • 2. Not terrible (postman panther)

    Votes: 9 6.7%
  • 3. Fine (happy panther)

    Votes: 46 34.1%
  • 4. Great (golfing panther)

    Votes: 80 59.3%

  • Total voters
    135
So let me get this right... You buy a piece of equipment to make the inaudible noise even more inaudible? Am I missing something here?
Yes. My bedside setup gets mains hum from the Mac mini, which I hear through headphones. I have to move the little topping dac and amp away.
 
I used the Intona high speed isolators they aren’t foo but I only found one case ( a very poorly designed dac ) where they made an audible difference.
Well designed equipment XLR connections job done.
Keith
And this was Amir’s conclusion in his review of the intona

Intona knows what they are doing when it comes to proper, professional USB isolators. As much as audiophiles are running to them to buy their products, I cannot recommend it for this application. Any half-decent DAC -- and I am talking $99 and above -- produces great performance by filtering its own USB power.

So I’m confused, do we need these things or not?
 
These isolators can get rid of very much audible mains hum, GPU whine, and other ground loop induces noises.

If you don't have such issues, then an isolator is pointless.

If you do, then they're an effective solution.
are there any known downsides?
 
If you use well designed equipment in the first instance then no , the one unit it helped was an Audio Note U.K. dac, whose owner has written that digital is akin to chopping up a cow for mince then trying to re-assemble!
Keith
 
Could we say any DAC that causes ground loops is (slightly?) at fault and an unfinished product?

I’d feel cheated, like I bought an “incomplete” device or faulty design.
 
You can get a leather case for the Neutron

 
Nice to see simple devices designed to do one thing, do it well, especially in the realm of snake oil USB cables, devices and claims.

Martin
 
So let me get this right... You buy a piece of equipment to make the inaudible noise even more inaudible? Am I missing something here?

@staticV3 is right, when your config is suffering from the ground loop noise then USB isolator can solve it, or you can also solve it using the Optical Toslink. This idea is to disconnect the ground of active devices.

In this review the noise of the DAC without USB isolator is low, you are correct, but it is so in this given case and even though USB isolators demonstrated their ability to eliminate the added noise by disconnecting the grounds of 2 active AC-powered devices - PC and DAC itself.

The amount of noise depends on the configuration of the system because all systems are different and have different components with different side effects.

For example, in my config I can easily hear noise (like modem communication) when something happens over USB bus, or just periodic ticks, also low-frequency hum. In my system ground loop is created via the external speakers which have 2 line-ins: one line-in is connected to PC's sound card, another line-in to my DAP which in its turn is connected to PC via USB. Even at low volume I can hear annoying noise. Connecting DAP via USB isolator disconnected grounds and solved noise problem completely - I get absolute silence even if I set amp of the speakers to its max amplification.
 
Could we say any DAC that causes ground loops is (slightly?) at fault and an unfinished product? (...)

Most usually it's not one specific device causing a ground loop, but rather the combination of equipment and circumstances. For example, you might live in a multi-apartment building, in which the cable or satellite TV/radio outlet ground might have a slightly different potential than the power outlet safety ground in the apartments. Now, let's assume that you so far had no ground hum problem with your hifi system, as all of its components happen to be safety class II devices and only the tuner is connected to the cable/satellite outlet - but then you have the idea, that you finally want to add a PC, that happens to be safety class I (be it equipped with onboard sound hardware, an internal sound card or an external USB sound interface or DAC), and now you're getting a very fat ground loop hum due to the two different ground potentials. Before USB isolators were offered, you then only had two choices: You could either insert an antenna ground isolator (which might not work in case of satellite TV/radio, though) or a usually transformer-based isolator for the analogue audio connection. Whereas with a USB isolator you have a third option specifically for USB-attached audio devices.

Greetings from Munich!

Manfred / lini
 
@staticV3 is right, when your config is suffering from the ground loop noise then USB isolator can solve it, or you can also solve it using the Optical Toslink. This idea is to disconnect the ground of active devices.

In this review the noise of the DAC without USB isolator is low, you are correct, but it is so in this given case and even though USB isolators demonstrated their ability to eliminate the added noise by disconnecting the grounds of 2 active AC-powered devices - PC and DAC itself.

The amount of noise depends on the configuration of the system because all systems are different and have different components with different side effects.

For example, in my config I can easily hear noise (like modem communication) when something happens over USB bus, or just periodic ticks, also low-frequency hum. In my system ground loop is created via the external speakers which have 2 line-ins: one line-in is connected to PC's sound card, another line-in to my DAP which in its turn is connected to PC via USB. Even at low volume I can hear annoying noise. Connecting DAP via USB isolator disconnected grounds and solved noise problem completely - I get absolute silence even if I set amp of the speakers to its max amplification.
I think Amir's testing would be more useful if he could introduce "noise" into the signal somehow and see how much the gear attenuates it. If I understand the measurements, he's basically testing a "clean" signal to start with. I'm not sure this is an accurate test of the effectiveness.
 
I think Amir's testing would be more useful if he could introduce "noise" into the signal somehow and see how much the gear attenuates it. If I understand the measurements, he's basically testing a "clean" signal to start with. I'm not sure this is an accurate test of the effectiveness.

Isolator primarily is not a filter, therefore measuring how much noise it can eliminate is probably not its primary metrics. It damps noise from the incoming USB connection (VBUS connection) but still its primary function - disconnect grounds, VBUS and active signal paths (D+/D-) galvanically. Digital USB signal is re-played by IC, power is transferred by the push-pull transformer circuit. Therefore there is no physical connection between input and output of USB isolator device and that is how ground-loop noise is eliminated. In the review you see the noise (event though it is small but it is still there) and with USB isolator it is fully eliminated, you can then extrapolate it to a more worst case scenario.
 
Many DACs incorporate USB isolation, e.g. Schiit describes their Unison USB as providing “complete electromagnetic and electrostatic isolation.”

It is not USB isolation, it is usually a common mode filter + ESD protecting diode, the full name of these ICs - Common-mode ElectroMagnetic Interference (EMI) filters with integrated ElectroStatic Discharge (ESD) protection. It is usually a very small IC which is put right after the USB receptacle. Without it your device can be killed by electrostatic discharge. This IC is normally present on 100% of USB devices, including the ESD diodes on Line-out jacks. Mentioning it explicitly by the producer is probably a marketing overkill :)
 
I get, what sounds like GPU whine, over HDMI. Any suggestions on available products or otherwise to tackle this?
 
Ok, so are you now saying Amir that USB filters do something useful, this would seem to be opposite of your previous views.
In an audio context, does it make the device sound better?
In any other context, does it improve data quality?
If neither, what's the point?
Will you soon be working for PS audio?
 
Ok, so are you now saying Amir that USB filters do something useful, this would seem to be opposite of your previous views.
In an audio context, does it make the device sound better?
In any other context, does it improve data quality?
If neither, what's the point?
Will you soon be working for PS audio?
What previous views are you refering to exactly?
 
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