As to its headphone amp:
HILO boasts plenty of headroom for both sensitive earphones, and for full-size headphones. Hiss levels through the Ultrasone IQ, for instance, fall just below those heard through Astell & Kern’s MKI AK100. Unlike the AK100, it drives them perfectly, with no loss in frequency response, with only small collapses of channel crosstalk, and with phenomenally low levels of distortion.
It doesn’t power full-size headphones to the same levels of which Goldmun’s God-like TELOS is capable. Like TELOS, HILO drives headphones at max volume with nary an IMD error, and mostly sizzle-free. At max volume the DT880/600 gets uncomfortably loud, but audiophiles interested in investing in hearing aids probably could do with a few more decibels.
Both its headphone amp and TRS monitor output are governed by a separate DAC. Which makes sense. As nearly flawlessly as it handles power, HILO’s headphone output tops out just above the theoretical limits of 16-bit audio. Therefore, it won’t resolve the dynamic range, the noise levels, or the distortion figures necessary to properly render hi-res material. That said, under load, even the best discrete headphone amps can’t keep up with 24-bit spec.
For hi-impedance headphones HILO outputs an evenly detailed stereo image that plays no favors. Largely, HILO ignores loads. Even the most sensitive and current-hungry headphones and earphones impose very little load on HILO’s headphone amp, ensuring that their output signals stay as flat as possible. The only artefact is a sometime-audible default to brighter highs and mids, but only when running CIEMs and certain portable headphones.
The only DAC/headphone amp whose character reminds me of HILO is the Centrance DACmini,(reviewed here), and that only when driving low-current loads. The sense of space HILO describes is huge, noiseless, and Z-axis detailed. Ever so slightly, it errs dark.
Which, considering its professional roots, is probably a good thing. It’s a perfect match for the DT880, the DT990, the K701, the HD800, and other headphones that people sometimes call _clinical_.
No, not mournful, effusive, or even lush. It really is like a DACmini with a perfect output section. You can plug in the lowest-Ω of earphones and headphones and barely drag its crosstalk values down. Distortion figures are way, way, way below any similarly priced or spec’d DAC/amp unit I’ve tried, and when driving earphones far below top-flight players such as the Astell&Kern AK240.
Dynamic range hovers around 99dB despite the load and signal-noise levels, at 99dB, loaded or unloaded, are beyond reproach. The frequency response is perfectly level from 15Hz to 20kHz and harmonic distortion, even under load of the Earsonics SM2 earphone, never dips below 70dB.
You will hear everything your music has to offer. You just won’t hear it like a scalpel to the ear. Much of that probably comes down to the parity of the dynamic contrast between lows, mids, and highs. And all of that is liberally stuffed into a copiously large stereo space.
With the proviso of absolute sound pressure, HILO is an animal.
A panther, that is. Not quite a lion. Black, dark, ferocious, but when it’s set to growl at top volume, it won’t rattle your headphones quite like the king. That accolade goes to the Goldmund TELOS, or the Studio SIX.
HILO’s volume works on a logarithmic scale, so even if you plug in very sensitive earphones, you will have a dozen or so turns before your earphones get too loud. As you can guess, channel balance isn’t a problem. Toward to top of the scale, volume scales up drastically. So, even if you’re hitting 70% or 80% of the volume scale and you think you’ve reached the limits of what HILO is capable, think again. Your 600Ω DT880 still has room. And even set at 100%, HILO’s signal is in perfect form. Unelss forced through something insane like an SM2, HILO suffers no IMD defaults at high volumes. That is because HILO’s output is totally stable.
But, because its headphone DAC is stuck at something near 99dB in all metrics, HILO’s utility as a hi-resolution 24-bit headphone amp, is academic. Sure, it sounds great at 24-bit, and natively decodes DSD, and it never, ever hiccups, but if you’re a hardcore headphone listener, you’ll need to default to HILO’s XLR output and an outboard amp. Even then, I doubt that your fancy-pants outboard headphone amp will do either HILO’s XLR outs or your 24-bit audio, justice.
Another thing: HILO’s headphone output is single-ended. If you’re a balanced bloke or bloket, you’ll have to work HILO’s XLRs.
HILO: you are brilliant. You are stable. You are the best damn one-box unit I’ve ever used, ever seen, and likely will own. Yes, I want this thing.
Lynx Studio Technology HILO nails stupid geek stuff like RMAA and square wave testing. It nails the dubbing of analogue stuff to digital. And it is a bullet-proof DAC. Single-ended or not, its headphone amp is great. It takes a while to learn, but it will be ready with a new card when the next computer connection comes out.
To be honest, I didn’t expect HILO to be as impressive as it is. And to be just as honest, I’ve saved up all the yennies necessary to secure one for my desk.
HILO, you will be mine.