The iFi Schiit experience

[G8YU]

The DAC and source USB cable used for this review is a Schiit Gungnir and XLO UltraPlus USB respectively. Music source is a laptop running Windows 7.

When I heard about iFi audio I became interested in their products meant to improve USB audio. I'll leave full product descriptions for the ifi website. Here's the basics: the iUSB Power, powered from it's own AC adapter, takes the USB input from your source and splits the power from the data. The Gemini USB cable carries the signal and power physically separated in their own wires from the iUSB Power to the iPurifier (which plugs into your DAC). Just as the name suggests, the iPurifier cleans up the signal.

I intended to try only the iPurifier. Before I clicked "Purchase" I thought: Well the iUSB Power has favorable reviews and isn't exactly expensive; and, of course, I have to get the Gemini to get the full potential from the iUSB Power. Then, as I'm about to buy all three, I thought: Wait, I'm about to spend more than half the price of my Schiit Gungnir on things that might slightly improve USB sound quality; and the Gungnir USB input is supposed to be very good already. Oh well, it's not a waste of money if I send them back when they don't help.

Spoiler alert: The ifi stuff isn't getting sent back.
First I used the iPurifier by itself. Intallation is easy. Unplug the USB cable at the DAC, insert the USB cable into the iPurifier then the iPurifier plugs into the DAC. The changes it brought were immediate and obvious. The ambience and reverb were increased, which at first seemed overpowering. As my brain got accustomed to the increased ambient information, I noticed the increase in transparency and air. The music sound-stage also seemed closer with better focused and detailed images of instruments and voice. Almost forgot to mention, there was an apparent increase overall in volume.

Then I added the iUSB Power and Gemini which connects between the music source USB cable and the iPurifier. The improvements were mostly of the subtle refinement variety. The sound was smoother and there was a bit more detail and image focus. Turning on the IsoEarth switch mostly just seemed to increase bass and/or weight. I did try the iUSB Power and Gemini without the iPurifier. The results were basically as expected. The sound was a little bit more detailed, smoother and the sound-stage was improved; but it lacked the degree of eye-opening improvements that the iPurifier could bring.

To sum up what these ifi products did for the sound. It was like moving from a seat that was rows back from the stage in an acoustically damped space to go up to the stage and hear a more immersive and alive sound with resolution and clarity. I knew my USB sound was lacking in comparison to CD on optical input. With the ifi additions the USB sound now surpasses the sound from CD in all but one area that I've noticed. CD over optical seems to offer a little more body than USB. For example, the impression I get from the sound of a guitar over USB is of strings vibrating; while the CD played over optical connection gives the impression of a guitar emitting the resonation of the strings.

Based on my experience, if you're considering these ifi products then the iPurifier is the best bang for your buck. The iPurifier alone won't completely clear up bad sounding USB audio though. For that you'll need the iUSB and Gemini which offer more complete and overall improvements in addition to the iPurifier; but at a much higher price. I think these ifi products were aimed more to help DACs powered from the USB connection; which is another reason for my surprise at how they transformed the USB audio of my Schiit Gungnir. So, no matter your DAC, if you feel your music over USB is lacking, adding these ifi devices might help.

A more in-depth comparison:
I wasn't satisfied leaving such a simple description of the differences between a CD over optical and USB with the ifi devices. There was more going on than a difference in music body. Here is what I found after noting the differing characteristics across many songs of varying genre.
The sound from USB with the ifi devices could be described as slightly analytical, but only as compared to my reference, CD over optical. USB's tighter focused and defined instrumental images were on a sound-stage that was mostly in front of me with more air space around the instruments. There was also more inner detail and musical note sustain and decay were separated more from the ambient echo or reverb.
Now I see that CD over optical was more of a sound filling the room around me experience instead of having defined instrument images in front of me in my room. The musical note sustain and decay was more blended with the ambience, which must be what I initially identified as being more music body from CD over optical.

This review ended up being longer than I expected. I hope those who are looking for info relevant to DAC USB inputs and iFi products find my experience descriptions helpful.

Edit on 2/23/2014: If it makes any difference, I always have the iUSB Power placed on two model 1 Vibrapods; and never bothered trying it without them.