iFi iDefender 3.0 USB Ground Loop Eliminator

Well, only kind of. You have to REALLY make sure that the interference is coming from your usb port. I have an external audio interface powered by an external power supply. Anything I tried, it was always apparent that the only time I would get a hum on my monitors was when my USB cable was plugged into my PC. I would recommend doing this check first to see if you're getting these issues from your mains power (Ground loop or dirty power supply etc). Its worth checking as this is quite an investment to make. It's really important to note that this may not fix your monitor hum out right or at all without making sure you know the source of the issue.6 YEARS LATER EDIT:I came back to this review to make it a full 5 star review. I originally only made it 4 stars because of the price but it still works nicely to this day which helps justify it in my mind. Also, I had to set up my desk again recently and did not use the defender. Every time I played video games, I would get an awful hum over my monitors, even if completely muted. Realising I still had this in a draw, plugging it in eliminated the hum so this was fantastic to still have 6 years down the road. Highly recommend but still advise on troubleshooting first.

I use Cubase Pro with a Steinberg UR242 interface and Yamaha active speakers. For a very long time, I have endured a background 'modem type shwhistle' from the monitors which would cease if I disconnected the USB cable linking the interface to the computer.After much research, e.g. earth loops etc., I took a gamble on this device, which looks like it should cost only £4.99, not being over confident that it would work and worrying what the wife would say if she found out what I paid for it. It came in a sealed box which means that one cannot easily send it back, but I'm very pleased to say it worked! No more 'shwhistle'!

It worked for me, but out of interest I had a look at how well it breaks the grounds. It's not that well, measuring 200 ohms between the grounds at DC. So if it does not work for you that might might be why. I was hoping for something much greater than 200 ohms particularly since a typical domestic setup uses high-impedance inputs. At that impedance it wont silence ground noise but it might reduce it.It did enough for me anyway so 3 stars.

Does what it says on the tin,I was on the fence until I saw a review of someone with nearly the same setup as me and it fixed theirs,I have a focusrite 2i4 into some yamaha 5" monitors which had dreadful ground hum from my pc being in a different circuit, I don't have a perfectly 100% crisp sound but it has made any noise a 1/10 of the volume,+wish it was a bit cheaper for what it is but hey ho it does the job.

Truth be told, I was unconvinced and sure this would get back to amazon, but having tried a couple of cheaper solutions I had to give this a chance. I’ve put this little thing between the USB extension and the sound card (Zoom U24) and turned on my pc. Like other usb “silencer” I heard no noise, but in this case my recognised the soundcard.. This silencer works, it really does, no other sound than music, I’m quite impressed!

A little on the expensive side but does exactly what it claims. I am using this with a Behringer Q1002 USB Mixer / Audio Interface. Have been suffering with interference (buzz/hum) for ages. When I installed the ASIO driver (for low latency applications) the noise got worse. Based on the three 5* reviews here I bit the bullet and paid out the dosh. Couldn't be happier!

Just received the iDefender and tested it with a bunch of different devices and it doesn't change a thing. The noise is still there and won't go away.It may just be a faulty device and if so i am really disappointed.Expected it to remove this awful noise but I am still stuck with it :(

Used between Mac and Denon PMA-2500NE. Mac is on different ring main.Ground loop issue only when AV receiver is also connected to Denon's HT BypassVery little negative effect on sound quality and does decrease hum from just audible from listening position to not audible from listening position for myself but my son with younger ears can still hear the hum from listening position. I can still hear from closer.So improves but doesn't fully solve