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2nd opinion from the dark side - John Darko of chimes in: My current main system comes with less wallet damage than Capt'n Sraj's - Magnepan $600/pr MMG powered by an AU$1.900 Audio-gd Master 10 integrated pumping 500 much needed wpc into the Maggies' 4-ohm load. Despite being the priciest unit in the chain, the Hex was in no way out of place in more wallet-friendly company. This amplifier/loudspeaker pairing has little trouble exposing upstream changes. A harsh truth that nearly every digital audio newcomer must face? Stock USB on many DACs just ain’t that good. So long as these more washed-out sounding USB implementations abound, the likes of Audiophilleo, John Kenny, W4S, Stello and KingRex (et al) will be called upon for their USB-S/PDIF bypass boxes.

Start at the end. The optional USB implementation on the Metrum Hex is a knockout. It’s a modified OEM board from M2Tech which in turn is based upon the popular Mk1 hiFace. Inside the Hex main man Cees Ruijtenberg has the M2Tech board up and at 'em with a 15V linear regulated power supply. End-user M2Tech drivers are required to get up and running and bring with them the usual caveat of all Mk1 hiFace devices: there exists an audio lag when watching movies and TV.  I confirmed this to be true.

Why not a Mk2 hiFace? "We checked several USB designs and found it hard to verify standard products as thing will be different when built into the DAC especially when exacting our standards of how to match such devices to our electronics. For instance, the hiFace Mk2 (XMOS) is great for the money but surpassed by the hiFace Mk1 using separate linear regulated power supplies instead of USB power. Beside this we have deployed another receiver section in the Hex having lower jitter. The sum of these properties made us decide to use a modified OEM version of M2tech together with our electronics. Further it can be hard to find the best device. A cable for instance can be great for one type of interface while the score is low using another brand interface on the same cable. Another problem was that the fact that when no drivers are necessary for Macs it sometimes lead to errors (don’t ask me what people are doing on their machines!). We have tried to avoid this until such a time that this technology is rock stable and here the original hiFace was the most proven contender."

To best extract many a DAC’s core fundamentals in the <$3K sector, a USB-S/PDIF converter's intervention is required more often than not. But not here. The Hex's internalised USB option held steadfast against off-board devices with an ever-so-slender edge in the broadest inner-illumination avidity whereas external S/PDIF appendages from KingRex and Wyred4Sound stirred in a hint of brown sugar for slower fatter transient edges. Direct USB was peachy keen, cooler and leaner than indirect data transfer. Direct-to-Hex USB also was fast and more wide-eyed and vibrant than any of my bypass bricks. These deltas were small but underlined the emerging truth that USB doesn't have to be a bare-minimum connectivity hurdle jump. Cees - terrific job here.

Many prospective buyers might initially balk at the cost of Metrum's USB option (€168.00/~US$220). Think about it more carefully then. Once a minimum $300 is factored for a good off-board USB converter topped up with a $100 S/PDIF cable, the Metrum’s USB board begins to look increasingly attractive. There’s no Mk2 hiFace shortcut here. Powered by dirtier 5V from a host PC, that $200 device couldn't hex the Hex. Elijah Audio’s BPM splitter cable and the battery-pack UPower from KingRex soften the sound but burden one’s spend with an additional ~US$350. If you don't go for the onboard Metrum USB option, hold on to your converter. Like the Octave, the S/PDIF inputs of the Hex are transport-sensitive. Cees explains:

"About the optical or coax connection directly from PC, I agree with you that these kinds of outputs are worse compared to good CD players or media players. It's like a Ferrari on a sandy road. It's not usual to combine such expensive equipment with relatively cheap gear. So there are limits to the DAC's jitter handling. We'd have to put in a bigger piece of memory to buffer the data. As you probably know the data handling in a PC is more or less determined by the processor so there are gaps in the S/PDIF data stream... Jitter rejection with the Hex is <35pSec while the Octave is <40pSec."

Software playa
. On a Mountain Lion'd MacMini, the Audirvana+ beta wouldn't talk to the in-house Hex USB implementation. Audirvana's integer mode isn't possible with any Mk1 hiFace but even disabling that check box still couldn't coax sound. A+'s progress bar showed the track pre-load but the playback point marker refused to budge [affirmative also on my end but rebooting the non-beta version fixed it - Ed]. Odd. No such dramas occurred with Amarra [or PureMusic 1.88a - Ed]. Back to a non-beta Audirvana+ (1.3.5 sans Integer mode-tick box) and everything was tickety-boo once more. Later in the review period Audirvana + 1.4 bowed. Deselect direct mode and sound!

Monster, DVD-A rip. 24 bit. What's the sampling freq, Kenneth? 88.2kHz. Receiving a mixed reception at its release in 1995, this latter-career entry from R.E.M. has stood the test of time. Peter Buck's buzz-saw guitars weren't as transient driven as via the MyDAC. The Hex exposed an abundance of timbral information obfuscated by the Micromega unit. Strong suits from Metrum's statement unit were tonal density, timbral finessing and decidedly unexpected warmth. More specifically, warmth communicated as humidity rather than direct sunlight. The single-ended outputs on my review unit differed from Srajan's. Cees elaborates:

"Keep in mind when using the RCA output that both DACs aren't 100% comparable. The one I sent you has the Lundahl LL1527XL while Srajan has the LL1588 with +10dB more headroom and lower distortion. As an agent for me described, the 1527 is more romantic and warm [it is also used in the Linn Klimax] but the 1588 is more like the real world and closer to the XLR. Whilst your unit was in transit we evaluated the 1588 and decided to deliver both options". The takeaway from this takeaway meal is that you have seasoning options at order time.

On a balance beam. I next switched to balanced connections as the Audio-gd integrated allows for it. The incoming XLRs from a Peter Graves cable of Adelaide's Grave Science company subbed for Chris Sommovigo's Black Cat Morpheus interconnect. Here music played into thinner air. Tonal operating temperature dropped a degree for a slight improvement in detail magnification and an upward click in bass definition. I'm cognisant how these deltas could be simply attributed as much to the cable brand switch as the connection mode change.  Either way, for the electronic programming that underpins Liars' WIXIW the balanced routing was preferred. Single-ended Lundahl LL1527XL coupling had the edge—by a nose—with guitar-shred records like the aforementioned R.E.M. as well as Neil Young & Crazy Horse's Psychedelic Pill. Here I dug the Hex's nod to warm stickiness. It's not what I heard in the Octave last year which itself was slightly glassier, leaner and more diluted than its bigger/badder brother.

I heard none of the Octave’s glassy shimmer from the Hex. The horns on Thomas Dolby's Aliens Ate My Buick were emphatic and shapely. Blat by the butt load. The electric bass that underpins "The Ability To Swing" was abundant with textural information and sufficiently weighty that the song was driven pendulously by its core - er, swing.  Being a late 80's production, this record often displays hints of that era's shiny-polished production glare. Not with the Hex where thicker air plumped and softened the delivery without pulling a veil over details. The Hex’s window on the world was squeegee-clean. Very, very impressive.

Pressure and poundage meant that music didn't hang suspended mid air but was tightly anchored. An abundance of tonal heft ensured that Neil Young & Crazy Horse's epic "Ramada Inn" lurched low and tight across the room. Soundstage illumination didn't just rain down from house lights above, the players themselves lit up the song from within. Microdynamic shifts were rendered with similar inside-out pressure. The shape of Young's guitar was drawn first with transient edge, then filled with deeply saturated tonal colours. This quality alone marks the Hex a hero in its own price range. None of these attributes hindered the Hex's need for speed. It remains whip-crack fast. Elasticity with urgency.

Shake and bake
. A non-audiophile buddy has a phrase for certain techno tunes that wallop hard below the belt and sugar sparkle up top. He calls this quality "Tinkle-Beef" – the perfect description for the Metrum Hex then. The Octave could err toward leanness but the Hex fills you out with flesh and colour. Think sparkling mineral water flow for Octave but champagne cascade for the Hex. The latter spills with a broader spread of flavours and greater body. 

Icing. Balanced connectivity and the ability to run sample rates up to 192kHz make this already compelling proposition a damn-near must have. It’s a new reference for this fellow. Time for team Metrum to pop a cork.

: The get-out-of-jail-free card played by reviewers unable—or unwilling—to spill forth with comparative information is to seal the review envelope with the cliché that Product X "competes with units two or three times the price". I shall not insult your intelligence with the same here. A head-to-head between Product Hex and the Auralic Vega is penciled in for early 2013. The resulting commentary will be published on Digital Audio Review.