The iDefender USB Ground Isolator

[mediatechnology]

The iDefender3.0 plugs into your computer USB port and auto-detects if there is more than one earth and will ‘intelligently’ disconnect the computer earth for cleaner sound.

If your DAC is USB powered, the iDefender3.0 requires an external 5 volts to break the earth. It works pretty well with our 5-volt iPower (just saying!). Injecting clean power will ensure you get the maximum out of your USB audio.

iDefender USB Isolator: https://ifi-audio.com/products/idefender3-0/



The iDefender significantly lowered the noise floor of the Focusrite 2i2 I now use on the desktop machine for playback.
Without connecting external power the iDefender broke a ground loop that was producing a small amount of hum.
There was still some low-level USB hash.
It comes with a USB C Male to 2.5 mm Female DC power connector pigtail so you can use an off-the-shelf wall-wart switcher.
Once I externally powered the unit from a generic 5V 1A wall-wart the USB hash dropped out and I now hear only extremely low-level DAC noise at death-defying gains.

I'm going to move it to the workbench Focusrite 2i2 and see if I can measure the improvement.

Amazon stock these.
I bought a USB A to A version which looks like it has sold out and has been memory-holed by Amazon.
They still stock the USB A to C and C to C versions.

[mediatechnology]

I ordered a second iDefender from Amazon.
They were out of stock on the USB A to A version so I bought a USB C to C.

The Focusrite has a USB C female and for use with USB "A" a short adapter cable is supplied.
The cable is generic.

The iDefender USB C to C version passes USB signals to the Focusrite when 5V is not injected but when an external 5V supply is used the Focusrite cannot establish USB communications.

Using the same Focusrite, USB adapter cable and power supply the A to A version works - the C to C does not.

I bought a second USB A to A from B&H Video and we'll see how that works out.

I'll repost iDefender's response to my open ticket on the C to C version.

[mediatechnology]

I bought a second USB A to A from B&H Video and we'll see how that works out.

I'll repost iDefender's response to my open ticket on the C to C version.

The promptly-delivered USB C to C iDefender from B & H Video works flawlessly.
Now, both 2i2s have isolators.
My desktop PC's 2i2 is dead quiet.

I'll try to post some comparative measurement data for the test bench 2i2.

iDefender hasn't responded to my open ticket since last week.
I suppose it's moot since the unit being returned to Amazon is awaiting pickup.

This is the B & H link for the USB A to A: https://www.bhphotovideo.com/c/product/ ... _loop.html
Note that the pic for the product IS NOT A to A.