My results were consistent (visually, at least) with the many other measurements and corrections I’ve applied to this system in this room, from many different EQ schemes: same or similar dips and peaks, same or similar EQ compensations. Which is not to say that the audible results would necessarily be identical: far from it. As provided via Arcam, Dirac allows you to shape a “target curve” for each channel, using three “handles” to manipulate the onscreen curve; the program will then calculate filters to derive the attendant impulse response to achieve this response. This, of course, empowers the operator to cause all sorts of mayhem; fortunately, Dirac defaults to a standard all-channels target curve, which looked to me to be a classic Quad-tilt contour trending down perhaps 1 decibel per octave above 2 kilohertz or so. Once you’re finished exploring, you proceed to export the data to the AVR850—a simple drag ’n’ drop process, though the upload takes a few minutes. The Sound My first order of business was to check channel levels and speaker distances. The latter appeared spot-on; the Arcam displays these in milliseconds, not distances, but conversion is easy enough when the formula is as close-to-never-mind as 1 foot per millisecond. However, Dirac’s normalized channel levels are very low, so I added 6 dB to each manually, and I confirmed the balance the old-fashioned way, with an SPL meter; only two 2-dB adjustments were required. Comparing Arcam/Dirac’s EQ/correction with unprocessed sound is made easier through an “audition” mode available only while the Dirac application is running (on the computer) and communicating with the receiver. Even then, substantial level differences remain to obfuscate evaluation. Just the same, doing my best to level-compensate on the fly, I judged listening through Dirac to be very like listening through the better sort of correction, regardless of system (though I’m mostly thinking of upper-grade Audyssey). Which is to say: tighter, better-defined bass, mostly thanks to mitigation of my room’s modest 70-Hz-region mode, and clearer-but-not-brighter high treble, thanks (I surmise) to cancellation of some closer/stronger first-reflection effects. I wished, not for the first time, that there was some practical way to compare correction algorithms and systems. But in the case of the best such—and I certainly include Dirac Live in that class—the net result is kind of like taking the screen protector off of your smartphone: Everything looks the same, but more so. At the same time, I don’t mean to overstate; the differences, at least in my acoustically better-than-average room, were fairly subtle. Otherwise, I have very little to say about the Arcam’s sonic performance, which is good news. Everything I sent its way—whether CD, hi-res audio file, or SACD—sounded simply terrific: clean, dynamic, and musical. To cite one example, a recent addition to my SACD collection (an increasingly rare event, sadly) of Mussorgsky’s Pictures at an Exhibition (with Valery Gergiev leading the Mariinsky Orchestra) rolled across gloriously, with its slightly distant recording perspective well represented by ample surround-channel content, especially evident on the recurrent “Promenade” entries. To cite another example, an all-channels workout like Bonnie Raitt’s Road Tested, at club-like levels, similarly revealed no amplifier shortcomings. And extensive two-channel auditions were of the same fully dynamic, fully transparent nature, with no hint of dynamic shortfall or clipping—even at fully concert-like levels, and regardless of listening mode or program genre. With the support of my two external-amp channels, the same excellence came across on movie sound, with the expected wows of Dolby Atmos dimensionality. Both the verticality and the enhanced spaciousness of Atmos were amply evident on the trailers collection from Dolby’s own demo disc. A full-scale production like the recent Atmos-enabled reissue of Terminator 2: Judgment Day on Blu-ray was all there: loud, tall, and proud. Short form: The AVR850’s Class G amplification scores an unreserved pass, with honors. The Stuff As for the Arcam’s “extras” menu—well, it’s short, some might say refreshingly so. The AVR850 can stream audio via wired Ethernet (or a plugged-in USB drive) but only up to a 48-kHz sample rate—which means the convenience of music-server delivery of MP3, WMA, FLAC, WAV, and AAC files is on offer (not DSD), but not the quality, real or imagined, of hi-res audio files. Basic but nicely usable internet-radio streaming is on board, and a Spotify Connect hook lets you feed your Spot-i-monkey, but only by throwing content from a Spotify-logged device such as a smartphone. (I can’t speak for Arcam, but I certainly presume that if you can afford a six-large receiver, you probably can also afford the streaming controller or hi-res DAC of your choice.) As already mentioned, the AVR850’s channels 6 and 7 can be assigned to a second stereo zone, and there’s a Zone 2 HDMI output; both have independent source and volume control. (It’s a fixed setting, however, so having both four height channels and a second zone would require four channels of outboard amplification.) HDMI facilities are all v2.0a/HDCP 2.2, so 4K/Ultra HD readiness isn’t a problem. And DTS:X readiness is promised via the usual firmware update. Arcam eschews network-access firmware updates (a security measure, I was told, but the fact that successful implementation is a daunting task even for large manufacturers may have played a part), which means the eventual update will be via USB memory, copied from a computer download. The Arcam receiver can scale 1080p (and only 1080p) to 4K. Dolby Volume (with adjustable leveling), that oft-overlooked but real-world-handy feature, is on board and selectable to default by input. The remote control commands the AVR850 very effectively. It’s keys are unusually generously spaced and well laid out, with contrasting colors, shapes, and sizes, plus full backlighting in response to any button press. A+, old chaps. There’s no direct access for much beyond volume, mute, and input select. But the occasional trip to the menu for channel-level touch-ups or whatever is made less onerous by fast onscreen response and clean, unfussy textual displays. And I must make mention of Arcam’s excellent manual. It’s more than 4 pounds and over 300 pages—but only because you get eight languages. The English section is a terse but complete 44 pages. The Sum-Up Obviously, you can buy an A/V receiver for half or even one-third the Arcam’s cost that will offer 7.1.4 Atmos and similar power ratings—I repeat, ratings, though perhaps not real power—plus wireless this ’n’ that and some other features you may well value, such as full-resolution hi-res audio streaming and maybe even a couple more amp channels. For their part, Arcam deems the AVR850’s competitors to be audio separates more than other AVRs. So whether you think Arcam is sensibly high end or simply smokin’ something special with the AVR 850’s price tag comes down to how you vote on three points. First, your worldview on amplifier quality (apart from quantity, of which the AVR850 proved to have plenty). Second, Dirac Live: better, worse, or same-diff as Audyssey XT32 or whatever or any fill-in-the-blank proprietary auto setup/EQ? And third, the ineffables of look, feel, and the je ne sais quois of Euro-design and top-grade execution. However you come down on those, though, there’s no denying the impressive sound that comes from Arcam’s latest all-in-one.