The iDefender+ is a more specialised USB audio device, specifically designed to
tackle ground (or earth) loops that can cause real issues with some computer-based
systems, typically resulting in an irritating buzz or hum from the speakers. When plugged into the source device’s USB socket, the iDefender+ detects whether
there is a ground loop problem, caused by the presence of multiple earths that add
noise. It breaks the ground loop by ‘intelligently’ disconnecting the computer’s
earth; as well as eradicating audible ground-loop hum it lowers the system noise
floor, improving resolution and dynamic contrast.
When used with a DAC that relies on USB power from a computer, rather than
power from the mains or a built-in battery, 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 power from the
external supply; if a high-quality, low-noise power adapter such as iFi’s iPower is
used, the performance of the USB DAC will be significantly improved.
Like the iSilencer+, the iDefender+ upgrades the performance of the outgoing
iDefender3.0 with the addition of low-ESR Tantalum capacitors for input and output
filtering. It, too, is available in three versions to suit the connected equipment –
USB-A to USB-A, USB-C to USB-A, and USB-C to USB-C. Again, the USB3.0 and
USB2.0 standards are supported and the connectors are gold plated.