JDS Synapse & Neutron V1 USB Isolators Review

[welwynnick]

It does make me think that one of the more up-market DACs with AES/EBU input may actually have an advantage.

 

[bboris77]

If one does not have an actual ground loop, the benefits of USB isolators are marginal and inaudible. However, these little gems can be a life saver for people who do have actual ground loops where the benefits are very real and easily audible. A few years ago, I had a PC with a powerful graphic card that produced a lot of coil whine and electronic noise. This PC used a three-prong grounded plug. I also had a headphone amp and a DAC that used three-prong grounded plugs. When I connected all these together, there were at least three different paths to the ground and I always heard a slight buzzing in my headphones whenever there was any activity on the GPU. The only way to fix it was to either use an USB isolator between the PC and the DAC or run toslink from the PC to the DAC.

 

[phoenixdogfan]

"If you are using balanced output in your downstream device (again, such as DAC), there is little import to this..." I knew there was a reason I interconnect everything I own with Mogami 2534 balanced XLR cable. Thank you for reminding me in this fine review, Amir.

 

[dmitrykos]

A THD+N reduction by nearly 0.0001%! :-D

Actually by around 39%: ((0.000126 - 0.000206) / 0.000206) * 100 = -38.83%

But it's for a given configuration/test scenario.

Result will change depending on the connected devices. In my tests with PC -> USB DAC (Apple USB-C dongle) -> capturing PC (simulates AC-powered amplifier) with and without USB isolator the noise from AC (50 Hz) and high-frequency noise were dominating quite noticeably without USB isolator:

 

[Sir Sanders Zingmore]

What previous views are you refering to exactly?

One example quoted in post #22 of this very thread.

Similar comments in his review of the Uptone device

Despite so many defenders of this class of products, measurements and objective analysis of the devices lends to no useable benefits. High performance DACs are designed to sound and measure excellently without such tweaks (after all, if there was something to these devices, they would include them in the DACs themselves at the prices they are charging us).

 

[pablolie]

Actually by around 39%: ((0.000126 - 0.000206) / 0.000206) * 100 = -38.83%

But it's for a given configuration/test scenario.

Result will change depending on the connected devices. In my tests with PC -> USB DAC (Apple USB-C dongle) -> capturing PC (simulates AC-powered amplifier) with and without USB isolator the noise from AC (50 Hz) and high-frequency noise were dominating quite noticeably without USB isolator:

View attachment 412627 View attachment 412628

Nah. The *difference* is a simple subtraction. i.e. the first operation in your formula.

The relative *percentage improvement* is what you are presenting correctly, but I was referring to the former. I know it is pedantic, but there is a difference between the two - as in "car A is 20km/h faster than car B", or saying "car A is 20% faster than car B" (provided car A tops out at 120km/h and car B at 100). Problem with the latter form of presenting the data is that, because it is relative, the "significant improvement" may be irrelevant if the performance of either comparative data point sucks...

 

[lini]

I get, what sounds like GPU whine, over HDMI. Any suggestions on available products or otherwise to tackle this?

You could ask ifi/SilentPower, whether their HDMI Silencer is also supposed to work for audio data transfers. The product description would only appear to mention positive effects on the video side, but maybe its not limited to that (their product descriptions tend to bit a bit squishy anyway...).

Greetings from Munich!

Manfred / lini

 

[dmitrykos]

Problem with the latter form of presenting the data is that, because it is relative, the "significant improvement" may be irrelevant if the performance of either comparative data point sucks...

It depends how you look at it. To get to 0.000126 from 0.000206 for a hw design of the DAC would cost quite a lot of design efforts. But, without isolated USB port these efforts will probably be useless as per review results because ground loop noise can't be tackled without isolation as this kind of noise affects practically whole audio spectrum. Also, do not forget that AP measuring equipment is ultra-low noise. If instead of AP would be some AC-powered amplifier then noise could be more intensive causing much higher THD+N.

 

[Ajax]

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?

A very unnecessary and derogatry comment.

Amir tests products to determine if they are "fit for purpose" as decribed by the manufacturer. How you interpret his test results and make use of that information is up to you. His reviews have uncoverred many "jewels"and I have benefited greatly from them.

Respect has been earned and warranted.

 

[Esprit]

A ranking of these 4/5 products?
So far I have always "eliminated" the tension on the USB cable (in the past also on Firewire).

 

[pablolie]

It depends how you look at it. To get to 0.000126 from 0.000206 for a hw design of the DAC would cost quite a lot of design efforts. But, without isolated USB port these efforts will probably be useless as per review results because ground loop noise can't be tackled without isolation as this kind of noise affects practically whole audio spectrum. Also, do not forget that AP measuring equipment is ultra-low noise. If instead of AP would be some AC-powered amplifier then noise could be more intensive causing much higher THD+N.

200% agreed.

That said, the THD+N doesn't seem to be much of an issue here starting at 0.000206. If I recall correctly, my Class D amp runs in around 0.0035% THD+N...

 

[kyuu]

Would an isolator like this also add value for HDMI signals?

If you're having an issue with noise from a ground loop via the HDMI connection, sure.

 

[amirm]

Ok, so are you now saying Amir that USB filters do something useful, this would seem to be opposite of your previous views.

I see the confusion. There are two classes of isolators/reclockers, filters that are being sold to audiophiles:

Class 1: they claim that even if you are not hearing any noise from your system now, that these products improve its sonic fidelity by widening soundstage, blacker blacks, more "analog sound," sound that is more like live music, etc. Nothing in this review validates such claims. And previous tests have shown the same in taking a perfectly working system and showing that such devices do not change their output.

Class 2: these are products that are aimed at people who have real problems. They have ground loops or "hear" their computer working as the noise profile changes with system activity. This is a serious problem that needs resolution. Many people report them and we scramble to make suggestions to solve these problems. One solution as stated in the review is to isolate the PC using optical Toslink. The other, is using these USB isolators.

So all depends on company claim and what customers buy them for. That defines how I test and recommend it.

 

[amirm]

A THD+N reduction by nearly 0.0001%! :-D

Actually, when I first started, it was much wider gap. But as soon as I grounded the device and then ungrounded it, it settled to lower value you see in the review. Leakage due to capacitance can be variable that way with the cap getting charged up/discharged.

 

[the_brunx]

Thanks Amir!

Is it a myth or no that ferrite beads can isolate a USB cable for 1$ ?

They provide no isolation. And the filtering they do is only effective at much higher frequencies, hundreds of Kilohertz whereas these products are operating in audio band.

I know a case where someone lived next to a radio station, amateur radio in that case, and had noises coming out of he’s speakers whenever the station operator was sending. Ferrite beads on cables can sometimes help in such a case. Don’t know about USB cables though.

 

[amirm]

I know a case where someone lived next to a radio station, amateur radio in that case, and had noises coming out of he’s speakers whenever the station operator was sending. Ferrite beads on cables can sometimes help in such a case. Don’t know about USB cables though.

Typical an AM radio which needs long wires as antennas to be picked up. The signal gets demodulated in the transistor junction if the audio gear doesn't have a filter for it, allowing the content to be heard.

 

[AndyBeckett]

A very unnecessary and derogatry comment.

Amir tests products to determine if they are "fit for purpose" as decribed by the manufacturer. How you interpret his test results and make use of that information is up to you. His reviews have uncoverred many "jewels"and I have benefited greatly from his reviews.

Respect has been earned and warranted.

Amir was able to respond in a professional way, as I would expect of him. He didn't take offence to my mild ribbing.
Perhaps you should learn from him.

 

[AndyBeckett]

I see the confusion. There are two classes of isolators/reclockers, filters that are being sold to audiophiles:

Class 1: they claim that even if you are not hearing any noise from your system now, that these products improve its sonic fidelity by widening soundstage, blacker blacks, more "analog sound," sound that is more like live music, etc. Nothing in this review validates such claims. And previous tests have shown the same in taking a perfectly working system and showing that such devices do not change their output.

Class 2: these are products that are aimed at people who have real problems. They have ground loops or "hear" their computer working as the noise profile changes with system activity. This is a serious problem that needs resolution. Many people report them and we scramble to make suggestions to solve these problems. One solution as stated in the review is to isolate the PC using optical Toslink. The other, is using these USB isolators.

So all depends on company claim and what customers buy them for. That defines how I test and recommend it.

Thanks Amir.

I'm intrigued. All devices could have potential grounding issues but most people don't suffer. Is this a problem that can be defined?
For example, I have no issues using a PC connected to a DAC via USB and connected to an amp via RCA.

 

[AndyBeckett]

I know a case where someone lived next to a radio station, amateur radio in that case, and had noises coming out of he’s speakers whenever the station operator was sending. Ferrite beads on cables can sometimes help in such a case. Don’t know about USB cables though.

I had a basic amp (Pioneer A400) that once picked up transmissions from a fire engine across the street. Always found that very strange.

 

[CedarX]

Class 1: they claim that even if you are not hearing any noise from your system now, that these products improve its sonic fidelity by widening soundstage, blacker blacks, more "analog sound," sound that is more like live music, etc. Nothing in this review validates such claims. And previous tests have shown the same in taking a perfectly working system and showing that such devices do not change their output.

Note that Neutron has apparently changed their webpage: it used to have a “Must-have for audiophiles” qualifier—see @dmitrykos own post here:
Post in thread 'Neutron Hifi DAC V1'
https://audiosciencereview.com/forum/index.php?threads/neutron-hifi-dac-v1.53889/post-1963360

Glad they “corrected” this and now fall into the “Class 2”