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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
There is User Manual in Details page of the web site. Details page also lists the package contents which is just the device unit. Many users use own cables, therefore instead of bundling some basic cable which would create additional trash in the World there are more advanced USB cables offered at additional cost.

The side wit 2 ports is the one to which you connect your USB device (USB DAC, ...), and the side with one port is connected to USB host (PC, TV, Streamer, ...). 2-nd Micro-B port is only for additional isolated power delivery, in case USB DAC requires >400 mA. It is explained in User Manual.
Skimmed right over it ,I was staying more on the first page :( So am I reading it right as they want 3 feet on each side of USB Isolator? On this forum one getss their head ripped off if you mention a quality USB cable..
 
On this forum one getss their head ripped off if you mention a quality USB cable..

No extraordinary functionality is promised, just high quality of the materials to increase reliability and durability of the cable, therefore there's no reason for that :) From my own experience, I own several USB-C cables which came to me bundled with devices where one got oxidized USB-C connector and thus it sometimes does not establish connection to the connected device, another (from BlackBerry) got braid fell to pieces, another (from Samsung) got plastic connector's shell cracked and fell to pieces, some are too hard to bend and etc. These practical issues were addressed in Neutron HiFi cables and without additional marketing bla bla such as "better sound" and so on.
 
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My Synapse arrived this week. Holy crap it made a huuuuuge difference in my semi-balanced PC setup. Went from hum, buzz, crackling, you name it, to complete and utter silence where I couldn't even tell the equipment was on until I played some music.

In my case I knew something was up with the USB connection since all the garbage went away simply by disconnecting the USB cable. Which is NOT to say that if you don't hear a difference when doing this, that there isn't still a ground loop that might be affecting you (YMMV).

Only problem now, is that I periodically have to disconnect and reconnect the "input" USB cable to the Synapse since my laptop seems to no longer see the device after some period of time. Not a big hassle but still rather annoying.

EDIT: Connecting the Synapse directly to a USB port on my laptop, rather than to a hub, seems to have fixed this. Unfortunately(it adds a bit of inconvenience but goes with the territory I guess).
 
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Only problem now, is that I periodically have to disconnect and reconnect the "input" USB cable to the Synapse since my laptop seems to no longer see the device after some period of time. Not a big hassle but still rather annoying.
Might it be some power saving mode within windows?
 
Synapse is working very well for me. No USB dropouts whatsoever. Connected from a Surface Pro 4 -> Topping E70 DAC. I didn't have any ground issues, just OCD (a cheap way to ensure clean single ended return). I'm using the 3D printed version. The red colour contrasts well with the uniform black of the rest of my equipment, looks pretty cool.
 
Only problem now, is that I periodically have to disconnect and reconnect the "input" USB cable to the Synapse since my laptop seems to no longer see the device after some period of time. Not a big hassle but still rather annoying.

You could try switching off power saving on USB hub in Device Manager if it is Windows PC and check if this workaround helps. This setting can be on controller and USB hubs:

power-tweak.png

Why it can help:

Synapse is using TI IC for USB data isolation and its specification tells that TI chip supports L1 Sleep USB power saving mode in addition to L2. On contrary Analog, in specification to ADUM IC (used by Neutron Isolator V1), mentions that ADUM IC supports only L2 Suspend USB power saving mode (when there is no data on USB bus for 3 ms) and does not support L1 - "This mode is not supported by all hosts or devices. In addition, L1 suspend is not supported by the ADuM4165/ADuM4166 because the handshake packets are not detected or interpreted by the isolator". So, TI IC accepts L1 sleep packets from the Host to put IC into a sleep mode and that probably could be a reason of your issue - something goes wrong with sleep/resume states either in isolator's IC or connected USB device, it could be just a coincidence and specific timing issue related particularly to the connected devices.
 
These isolators can get rid of very much audible mains hum, GPU whine, and other ground loop induced noises.

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

If you do, then they're an effective solution.
Could you elaborate on how an USB isolator helps with GPU coil whine?
 
Could you elaborate on how an USB isolator helps with GPU coil whine?
They don't help with acoustic coil whine.

But there are many cases in which people can hear GPU activity as clicking/screeching through their USB DAC.

Putting an isolator in between will stop that.
 
They don't help with acoustic coil whine.

But there are many cases in which people can hear GPU activity as clicking/screeching through their USB DAC.

Putting an isolator in between will stop that.
I don't know if it was a ground loop causing anything of the sort, but I do recall before that I had situations where clicking my mouse would make noise in my speakers, and no, I didn't have any microphones on.
 
They don't help with acoustic coil whine.

But there are many cases in which people can hear GPU activity as clicking/screeching through their USB DAC.

Putting an isolator in between will stop that.
I would assume one of the main variables is simply either how much current is being drawn, or how fast it's changing (high di/dt) by the card and the system.
I don't know if it was a ground loop causing anything of the sort, but I do recall before that I had situations where clicking my mouse would make noise in my speakers, and no, I didn't have any microphones on.

If it only happens the first time such as when you sit down, then there's a good change it's a mild ESD type event.
It is persists and is occurs when one is in physical contact with the keyboard or mouse (wired), then it may involve the capacitive coupling between your body and the system.
 
If it only happens the first time such as when you sit down, then there's a good change it's a mild ESD type event.
It is persists and is occurs when one is in physical contact with the keyboard or mouse (wired), then it may involve the capacitive coupling between your body and the system.
Consistently.

Can you explain more about this capacitive coupling between my body and the "system"?
 
Consistently.

Can you explain more about this capacitive coupling between my body and the "system"?
Your body is basically a large wet sack (electrically speaking). The DC resistance across dry skin is in the 1 Mohm range, and typically has around 200 pF of capacitance. By touching something, you introduce a small but measurable electrical change. Most modern touch screens use a fine grid system to detect where your finger is touching it.
It generally is not a problem (used to be along time ago), and really only has an effect when the specific conditions are just right.

The other way it could influence the system and possibly cause noise is simply due to the change in electrical signals of the keyboard/mouse, or by the content on the monitor changing. For example, if it still happens with a wireless keyboard/mouse.

It's improbable for any particular person or system to experience it, but it can happen.

btw: I've heard it could have a similar effect on old style TV antennas by changing the electrical parameters enough. So you adjust it to get it perfect, but when you let go it gets bad reception again. Sounds plausible, but it could also be incorrect.
 
Your body is basically a large wet sack (electrically speaking). The DC resistance across dry skin is in the 1 Mohm range, and typically has around 200 pF of capacitance. By touching something, you introduce a small but measurable electrical change. Most modern touch screens use a fine grid system to detect where your finger is touching it.
It generally is not a problem (used to be along time ago), and really only has an effect when the specific conditions are just right.

The other way it could influence the system and possibly cause noise is simply due to the change in electrical signals of the keyboard/mouse, or by the content on the monitor changing. For example, if it still happens with a wireless keyboard/mouse.

It's improbable for any particular person or system to experience it, but it can happen.

btw: I've heard it could have a similar effect on old style TV antennas by changing the electrical parameters enough. So you adjust it to get it perfect, but when you let go it gets bad reception again. Sounds plausible, but it could also be incorrect.
Ah, I see. But the (extra) noise wouldn't happen just from holding onto my mouse or keyboard, just from actually clicking (actuating the microswitches under the mouse buttons).
 
When I am not using USB isolator and thus have a ground loop in this setup [PC -> DAP -> powered Speakers] then I can easily hear noise (like modem communication) from external speakers when files are being copied to my DAP over USB, there is no even physical interaction between human and equipment at that moment. It is not about ESD issue. USB communication is a burst of changes in voltage on USB bus, those changes induce additional noise. Clicking mouse is also a kind of USB event which causes electric activity in PC, not just in USB bus but also CPU, GPU which process the event associated with a mouse click. Ground loop provokes very easy induction of the noise from whatever is oscillating in the device.
 
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