Metrum Acoustics Hex digital converter

Equipment report
Digital-to-analog converters
Metrum Acoustics Hex
Metrum Acoustics Hex digital converter

Scale doesn’t always count in this business. Sure, the bigger companies have the marketing clout to get their products the widest exposure, and some of them have the R&D facilities to do things that small brands can only dream about. But, when it comes to inspiration, one man is as likely to succeed as 20 and that seems to be the case with Dutch electronics company Metrum Acoustics. The Hex is its latest and most ambitious converter, but it was preceded by two others of which the Octave still remains. That £699 non-oversampling (NOS) DAC is the best I’ve heard at its price point and some way beyond. It’s small, comes in two boxes and only has S/PDIF inputs, so no USB, but delivers stunning sound quality. As the name infers, it has eight DAC chips (four per channel) and these are of a type that Metrum describes rather vaguely as high speed for industrial applications, the point being that they are not off the shelf 24/192 chips that are found in most other DACs.

The Metrum converters will run at up to 24-bits/15MHz, so in speed terms are considerably more capable than they need to be, but apparently are not straight forward to implement in an audio circuit. The lack of a USB input was about the only thing standing between the Octave and global domination, that and the fact that Metrum is a small operation with rather limited clout in the market-place.

The company released its latest DAC in 2012, Hex has twice as many converter chips as Octave which makes you wonder why it has a name that means six, as it turns out the name is short for hexadecagon which is a sixteen sided object. The Hex is a single box converter with multiple S/PDIF inputs including BNC and the option of both asynchronous USB and/or AES/EBU. Outputs are both single ended, with Lundahl output transformers, and balanced which reflects the fact that Hex is a balanced or dual differential converter. I used the RCA phonos single ended output for this review.

It is solid rather than elaborate in construction, with buttons for each input and an LED on each that blinks when there is no signal. This is useful during set-up but slightly irritating when the DAC’s not in use. The key is to select the input that has a connection when you are using another source, presumably it’s only reviewers who have multiple converters powered up but only one connected to the source so this will not be an issue in normal situations.

In the system with a Naim UnitiServe hooked up to the BNC input Metrum Hex is a truly inspirational sounding DAC, it is relaxed, open, extremely revealing and has superb timing and dynamics. The Octave is good, but this is in another league to most of the other converters on the market, I don’t know which converter chips it uses but I urge other DAC makers to investigate at the earliest opportunity. I didn’t have one to hand but the DAC that comes to mind as being close in many respects is the MSB Platinum IV Signature, a £12,000 converter last time I looked and among the very best on the planet. The Hex really does punch at that level. It is high definition in terms of detail resolution, very strong on dynamics and beaufituly timed. You get all the life out of a recording without the grain that often accompanies vibrant sounding digital audio. It is vinyl standard in all except noise levels which are naturally much lower. It doesn’t sound like vinyl because there isn’t the character of mechanical playback that is intrinsic to the format but it does all the good things that vinyl can; energy, excitement and considerable musical communication. Put on a decent hi res recording like Antonio Forcione’s Meet Me in London (Naim Label, 24/192) and the musicians are placed firmly in the room in such living, breathing form that only your eyes will tell you it ain’t so. Despite Forcione’s undoubted skill on the acoustic guitar, it’s the fretless bass playing that caught my attention. It comes across because the Hex reveals almost as much about the quieter instruments in the mix as it does for those at centre stage. This is clearly an extremely quiet converter, one that keeps highs clean and presents them in a solid, tangible fashion so that they recreate the defining edges of each note in a convincing fashion.

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