Performance in practice
According to iFi, the iPurifier 3 has a hattrick of features that work together to create a perfectly pure USB signal: Reclock, Regenerate and Rebalance.
In layman’s terms, this means any timing errors, jitter and other impurities in the signal are removed, and a new, clean signal is generated and sent to the DAC. Rebalancing is supposed to reduce distortion from DC power offset, which, combined with iFi’s claimed 100x active noise cancellation tech, should leave the new signal without any hint of USB power-related noise.
I first compared the sound with and without the iPurifier in place. I then compared the iPurifier with two other devices used to ‘clean’ a USB signal: the $300 Ideon 3R Renaissance, and the $400 Matrix X-Spdif 2. The comparisons weren’t like for like given the price differences and the different technology used, but I figured the end result (audio quality) is all that matters, so I wanted to see what the much cheaper and simpler iPurifier was capable of.
Let’s get straight to the point: it’s very capable. By that I mean compared to the audio quality I’m hearing with my Mac mini connected directly to the DAC by USB, plugging in the iPurifier 3 into the chain immediately makes an audible, and beneficial, difference to the sound quality.
Specifically, I’m hearing a more spacious presentation with most of the tracks I was using, better separation between instruments (and between instruments and vocals), and a perceivably ‘darker’ noise floor, akin to closing the door and windows in an already quiet room.
Even though I use an Audio-gd R-28 as my DAC and amp, which features an FPGA processor that does its own cleaning and jitter reduction on the incoming signal, it’s still possible to hear the difference the iPurifier makes when in use, especially compared to listening with an unfiltered signal.
For example, what I sometimes hear as ‘ringing’ around the edge of female vocals is all but eliminated by the iPurifier. Norah Jones’s otherwise superb ‘Come Away With Me’ DSD is a case in point, where her vocals on some tracks sound a touch too shiny, is more focused and refined with the iPurifier.
Since the iPurifier not only re-clocks and regenerates the signal but also uses active noise cancellation on the incoming USB power line, I can’t be sure which part of the cleaning process has the biggest impact on the signal, but I can say for sure that whatever it’s doing, music sounds perceptibly better.
How does the performance of the iPurifier compare to the other two devices? The degree of spaciousness and ‘noise’ reduction was just about on par, perhaps a hair less, than with the Ideon. The Ideon has the added benefit of injecting ‘clean’ power from its own power supply, so if you have a particularly dirty power source, this could be an advantage in your system.
The Matrix can also use its own power source, but like the iPurifier works just fine in bus-powered mode. It not only galvanically isolates the incoming USB power source but also cleans and regenerates the signal before switching to a completely different output signal, in my case, I2S. Sonically the Matrix is a step up in terms of background noise, with everything sounding slightly less congested and finer details becoming more easily apparent. But again I stress the differences are small.
I’d say both the Ideon and Matrix do a better job, but at three times the price they are certainly not three times better; as always, the law of diminishing returns applies. The Matrix has other benefits aside from a cleaner signal – like being able to split the incoming USB signal across multiple DACs using different outputs – so its value isn’t limited to sound quality alone.
For closing thoughts and a final score, turn the page.