Traveling Companions: Headphone Amps from FiiO, iFi, and Miniwatt Page 4

Miniwatt n4: The Luxury Approach

Miniwatt's best known for their miniature tube amps, but with the new n4 ($488 )they've aimed squarely for the burgeoning desktop/portable USB DAC/headphone amp hybrid market. The leather-wrapped unit includes a bunch of upscale features, but the size indicates a convenience product, as does the inclusion of a digital volume control that takes over your desktop machine's system volume (a la the implementation of volume control used on the HRT HeadStreamer).

While the n4 isn't quite as miniscule as the HRT, it's quite compact - a fair bit more portable than the iFi, and while it's clearly not meant as a "portable" per se like the FiiO units or the HeadStreamer, it'll make a nice traveling companion for the right person. With its classy upholstery, just consider it a business class alternative.

I found the n4 much more convenient to use than the HeadStreamer in most cases - I'm a big fan of hardware volume control, especially when you're listening to program material with a good amount of dynamic range (which, one might expect, those looking for an ultra-high-rez device would be interested in. It worked wonderfully (and with zero setup) in most cases, only falling down on the job in conjunction with the high-rez player app Decibel, which obtains exclusive access to connected audio hardware and locks out the system volume control entirely - when using this app, I had to adjust output levels from the software's own device volume controller. Sound quality didn't suffer, but I found the combination less convenient. If you're using an app that makes use of system volume - i.e., playing back Apple Lossless from iTunes (or you're using Windows) - you'll do just fine.

Say what you will about the value of ultra-high-rez files, but plenty of folks want 'em, even if their relative rarity in the wild (not to mention the gigabyte-per-song file size) makes them something of a luxury product.And there are some out there who are ripping their pristine analog sources to such formats, so this may makes sense. Sure, a format that makes such storage demands is a luxury, but hey - this thing isn't wrapped in leather just for warmth (it actually runs pretty cool, by the way). For my part, I tend to stick to 24/96 and below, but I grabbed some 192 kHz tracks from 2L and the n4 dealt with them just fine. 

The onboard headphone amp doesn't quite have the juice to drive the HiFiMan HE-500 to my taste, but it does fine with the somewhat less power-hungry HE-400 (with which it sounded quite nice); any reasonably efficient headphone will be well served. I would like to have seen a bit more powerful amp in the unit (along with a 1/4-inch jack), but it's understandable, given that in a USB-powered device such as this there's only so much current to go around.I found the headphone output to be slightly hissy with sensitive IEMs (I tested with the Westone ES5s, the UE Personal Reference Monitor, and a handful of dynamics), roughly on par with the onboard headamp of the iFi iDAC, and somewhat noisier than the impressively quiet FiiO E07K.

If you need more oomph, you can always use the n4's RCA outputs to drive another headphone amp (I paired it with a Musical Fidelity V-Can, the FiiO E12, and the iFi iCan, with good results in each case). The line out was quiet and introduced no perceptible crud when compared to the other sources I had on hand.

Getting high-rez out of your Mac is as easy as plugging in; there's native support in the Mac OS for word length up to 24 bits (above that you'll require software that supports such things), and sampling rates up to 192 kHz. On Windows you'll need to install Miniwatt's driver (downloadable from the company's Web site). A minor nitpick: the device gets identified by the Mac as a generic "Speaker" and "S/PDIF Output" in the Mac's audio drop down; you'll also notice a pair of corresponding (and apparently nonexistent) inputs. The company's been updating firmware pretty frequently though, and we'd hope to see this point addressed in a future revision.

Is it all worth it? That depends. If your primary ultra-high-rez interest is the 192 kHz sampling rate and youdon't absolutely have to have 32-bit word length,the 24/192-capable iFi iDAC is probably a wiser choice; its headphone amp is significantly more capable and the unit costs a full $200 less, though the iFi it lacks the n4's neat slaved digital volume control and the S/PDIF coaxial output).  

For those looking for a do-it-all box in a compact package that can also do duty as an 32/192-capable USB-S/PDIF converter (and there are a number of computer audiophiles out there interested in such boxes to serve as bridges between FLAC playback software and pro-level DACs), the n4 is actually kind of a nice deal.