iFi audio iDefender+
Is your audio still taking a beating from buzz and hum?

iFi’s iDefender+ is for those battling with noisy audio due to unwanted ground loops in their audio chain.

Beat the buzz

Is your audio still plagued by hum and buzz?

Using multiple plugs within your audio chain means separate earth/ground points. These multiple earth or ground points cause a ground loop problem. This creates an unwanted chain of noise, buzz and distortion.

Struggle no more. iFi’s iDefender+ provides the simple, effective solution you need.

iFi audio iDefender+

Break the loop

When plugged into the source device’s USB socket, the iDefender+ detects whether there is a ground loop problem.

It breaks the ground loop by ‘intelligently’ disconnecting the computer’s earth and, as well as eradicating audible ground-loop hum, it lowers the system noise floor, improving resolution and dynamic contrast.

Using a USB DAC?

Are you using the iDefender+ with a DAC that relies on USB power from a computer rather than power from the mains or a built-in battery?

Good news. The iDefender+ offers an additional benefit. If an external power supply is plugged into the USB-C socket on its side, it blocks power from the computer and instead feeds the DAC with ‘clean’ power from the external supply.

If a high-quality, low-noise power adapter such as iFi’s iPower X is used, the performance of the USB DAC will be significantly improved.

iFi audio iDefender+

New and improved.

We’ve upgraded the circuitry; low-ESR tantalum capacitors have been added for improved input and output filtering.  Filtering capacitance has been increased 10-fold.

The iDefender+ now comes in 3 versions and includes the newer USB-C connector.

  • USB-A to USB-A
  • USB-C to USB-A
  • USB-C to USB-C

Beat the buzz with the iDefender+.

Kills USB power noise by ‘breaking’ the earth/ground loops in the correct way.

It significantly reduces the system noise floor and makes for better dynamic contrast, warmth and resolution.

Inject 5 volts of clean power clean via the ‘separate’ micro port. This disconnects the USB power from the PC and replaces it with clean external power. For ultra-low noise, use our 5-volt iPower X.

Adding the separate 5 volts to the unit is necessary to ‘break’ the earth/ground on USB-powered DACs. This is not required for DACs with an internally-powered USB section.

‘SuperSpeed’ USB 3.0 has a more exhaustive wiring specification which allows for a greater amount of audio transfer while still being backwards compatible. The units incorporate high-quality gold-plated connectors for optimal signal transfer.


USBSuper-Speed USB3.0 (and USB2.0 backwards compatible)
ConnectorsUSB3.0 gold-plated connectors
Dimensions50mm (I) x 20mm (w) x 9mm (h)
Weight6.6g (0.23oz)
Warranty period12 months


Resolved my ground loop problem, when used with external power supply!

I spent the last week tearing my hair out trying to diagnose a problem with loud, unwanted GPU noise bleeding through my external USB interface onto my speakers. After a LOT of trial and error, I was pretty confident that the noise was related to electrical ground loop interference from my PC, and that I needed an externally powered isolator like this one to resolve the issue. $50 feels extremely steep for how simple the device is, but lo and behold, it fixed my problem! I didn’t want to spring for their external power supply (for another, ridiculous $50), but used with an cheapo 5V phone charger it works fine.

I would definitely recommend it if you’re having a similar issue, with the caveat that it won’t magically resolve all types of noise and interference, just those related to ground loop interference and USB noise between components of a source device like a PC. Some of the reviewers are openly calling this item a scam, which it definitely isn’t- you just have to correctly diagnose your problem.

(Click name to read original review)
DAC (Digital-to-Analogue Converter)

DACs convert digital information, stored or streamed by computers, into music we can hear through speakers or headphones.

Every device that’s a source of digital sound has a built-in DAC (TVs, games consoles, CD players, phones, portable music players etc). Dedicated external DACs sound much better than standard DACs used in digital devices such as phones.

Ground Loops

In an electrical system, a Ground or Earth loop occurs when two points of an audio system both have a ground reference which causes a ‘potential voltage difference’ between them. Ground loops are a major cause of the noise, hum, and interference in audio, video, and computer systems.