Technics SU-GX70 Streaming Amplifier Review
David Price tries out this Japanese giant's latest 'Grand Class Network Audio Amplifier' for size…
SU-GX70 Streaming Amplifier
AUD $3,199 RRP
Back in the nineteen seventies, eighties and nineties, Technics was a permanent fixture on the shelves of hi-fi dealers – and, of course, sold its iconic SL-1200 turntable by the truckload to DJs and nightclubs. The brand became so popular that it almost became synonymous with a certain type of separates hi-fi. If you told your friend down the pub, “I've got a Technics”, it didn't need any further explanation – possibly perhaps aside from answering his question, “does it go really loud?” in the affirmative…
Like many Japanese brands, Technics started to lose interest in separates hi-fi at the beginning of the new millennium. The magic of AV and/or home theatre exerted a sort of cosmic magnetic pull, rather like that of the Moon upon the Earth, and this company and many of its peers gradually edged away from two-channel separates hi-fi, leaving only the SL-1200 to soak up residual demand. By the end of the decade, this too was gone – the presses used to die-cast its aluminium upper structure apparently having worn out due to age.
After some serious thinking about life, the universe and everything, the Technics brand moved back into the two-channel sphere in 2014 with a vengeance – under the guiding hand of its (then) Chief Technical Officer Tetsuya Itani, who joined the company back in 1980 – before even Compact Disc had been launched. He got the original turntable team back together, most of whom had retired, and rebooted the SL and SP series of quartz-locked, direct drive record players – and did it brilliantly. After that, the company has focused largely on amplification, and we've seen a new generation of digital amplifiers, the like of which no other manufacturer is doing, plus the occasional digital source component.
The Grand Class SU-GX70 you see here simply follows on with the company's ongoing roll-out of Technics amplification products. Costing about thirty percent less than the SU-G700 M2 I reviewed a year or so ago, this is a network streaming tuner/amplifier rather than the latter's simple integrated amplifier status. It attempts to do more than its costlier and physically larger brother for less. The question, then, is whether it succeeds and to whom does it appeal?
As its pricing and feature-set suggest, the SU-GX70 is aimed at more generalist buyer who wants the heart of a streaming system in one neat, slimline box. The SU-G700 M2, by the way, had quite a different potential customer in mind. In its case, it was going for a classic, old-school Technics amplifier buyer from the past. That meant the amp had to be physically big, loaded to the gunwales with technology and have vast amounts of power relative to its price rivals. The buyer for the 'GX70 wants something altogether more discrete, however, and something that's far better at multi-tasking.
The manufacturer describes this as “a high-spec streaming amplifier, combining the sonic genes of the acclaimed components collection with a wealth of connectivity options, including HDMI ARC for the first time.” It doesn't come as a complete surprise that the press release doesn't get very far before the word “hub” is mentioned! The SU-GX70 is said to combine Panasonic's expertise in video signal treatment with Technics' proprietary full-digital amplification technology.
The combination of streaming and the provision of HDMI ARC places it at the heart of a two-channel home entertainment system, the sort that's popular in Japan with its relatively small living spaces – especially for urban city dwellers living in eight-tatami apartments. It makes the SU-GX70 a kind of audio-video crossover product that may have less appeal to Western audiences with more space – although it's undoubtedly true that newbuild houses and apartments seem to be moving closer to Japanese dimensions, rather than the other way round!
Despite its video integration – which will be of huge utility to some, but not, I suspect, to most – Technics wants to reassure 'real hi-fi' fans that it's a pukka audiophile product. So, it contains a lot of connectivity and functionality for a slimline (430x98x368mm, HxWxD) and fairly light (6.6kg) device. You get a moving magnet phono input (2mV, 47k ohms), two analogue line inputs, one USB-A and one USB-B digital input, two TOSLINK optical digital ins, one coaxial digital in. There's the aforementioned HDMI ARC, one analogue preamp output, a headphone output, plus loudspeaker outputs.
Files supported include all the major ones, as you'd expect – WAV, FLAC, AIF, AAC, MP3, ALAC and DSD. The amp handles PCM up to 32-bit, 384kHz resolution and DSD up to 11.2MHz, plus MQA; AirPlay 2 and Bluetooth are standard. The tuner section includes DAB, DAB+ and FM. As far as the streaming side goes, it offers simple and direct access to Spotify, TIDAL, Deezer, Qobuz, and Amazon Music HD via the Chromecast platform.
The SU-GX70's amplifier section is basically a scaled-down version of that seen in the SU-G700M2 – complete with its so-called JENO Engine, Load Adaptive Phase Calibration, and Space Time. To learn more about these, please refer to my StereoNET review here. Suffice it to say that it puts out a claimed 2x 40W RMS into 8 ohms and 2x 80W RMS into 4, which is much lower than that of its bigger brother and rather underlines its intended purpose in life. The manufacturer says that a twin power supply has been fitted for a high signal-to-noise ratio, and there's a 'Clean Power Clock Generator' as seen in Technics' own Reference Class components for the best possible jitter performance.
In the flesh, so to speak, the SU-GX70 is a very attractive and neat little thing. Despite being built in Malaysia, it has the slick, precision feel of any component you'd expect that's made in Japan. The brushed aluminium fascia and crisp display confer a real sense of quality, and the pressed steel case is good enough to not draw attention to itself. The switchgear feels light and smooth but has a positive action – just as you'd expect from a Technics product. There's a choice of both silver and black finishes.
The downside is that the modestly-sized display isn't the easiest to read, and the menu system isn't the slickest to navigate. It's not bad, but we're a fair way away from Apple-style ergonomics here – and that's often where Japanese products fall down. Perhaps it's the price you pay for trying to integrate so many features into a small box? Still, there's always the app and the remote control feels pretty classy – so overall, the SU-GX70 turns out to be quite a nice thing to live with. Other supplied accessories include an indoor DAB aerial and a decently written owner's manual.
This is a polished and clean-sounding amplifier and one that's more powerful than its specifications suggest. Indeed, it has a quite 'pristine' sort of sound, as it makes pretty much any recording seem like it's a slick, sophisticated thing. This can be both good and bad, depending on what you're listening to and, indeed, your point of view. The most striking aspect of the SU-GX70 is just how well-behaved it is – whether you're playing the nineteen-seventies grunge of The Ramones or the eighties elegance of Sade, there's never anything to offend you. Tonally smooth and spatially impressive, there's much to like.
This is especially the case in Pure Amplification Mode, by the way – which powers down the network functionality and HDMI circuits, as well as the two antennas on the back panel. When this mode is selected, the sound gets cleaner and more three-dimensional, with a little more lustre and detail – although it's a fairly subtle sensation. Yet regardless of the mode setting, there's still a sense that Technics has gone for more of a generalist rather than a specialist audience with the SU-GX70 – it's less laser-focused on audiophiles than its bigger brother, for example.
This little amplifier is good but not brilliant in the sonic stakes, then. It is much less of a bruiser than the SU-G700 M2 and generally more vanilla in its voicing. Yet that doesn't make it worthy of condemnation, as it's also quite a lot cheaper and has more functionality. Take the SU-GX70 on these terms, and it's very endearing. For example, with the classic early eighties rock of Turn It On Again by Genesis, via my Cyrus CD Xt Signature CD transport, the Technics acquitted itself well. It majored on the song's distinctive bass guitar and drum kit-powered groove that makes things so enjoyable.
I found myself rather awed by Phil Collins' stick-work, this amplifier capturing many of the musical nuances going on and pushing them out through my NEAT Majistra standmount loudspeakers with aplomb. From memory, I'd say that this is at least as good as Primare's I15 Prisma, which is a close price rival to the Technics and very similar in terms of functionality. Actually, the GX70 may even be a little gutsier, as it appears to hold on better during musical climaxes and sounds subtly stronger in the bass, too. Tonally, it's on the ever-so-slightly warm side of neutral, making it a good match for coarser-sounding budget loudspeakers – but it has nowhere near the amount of euphonic colouration you get from a valve amplifier, of course.
It's only when you put this amplifier up against more 'focused' competition that it is found lacking – and that's not really fair as you end up comparing this hi-fi equivalent of an SUV to a sports car. The post-millennial funk of Daft Punk's Get Lucky came over very well whether streamed, played off my NAS drive, or via a direct digital input from silver disc. The Technics made a nice noise, with a good smattering of detail, plus it had the ability to let the listener follow the glorious interplay between bass guitar and rhythm guitar with relative ease. Yet, when you try to peer more closely into the mix, things get a little opaque. The SU-GX70 seems to round things off a bit, making the music not quite as crisp and explicit as it should be. The effect of this is that it doesn't really tug at your heartstrings as much as you might wish.
This is even more apparent when you wheel in some 'big guns' at this price point or close by. The recently reviewed Moon 250i V2, for example, seems to have a more natural tonality, better focus and grip, as does the Naim Nait XS 3. Both of these aren't a patch on the versatility of the Technics, by the way – so fans of the latter two amps would have to pay extra for some of the things that the Japanese amplifier does as standard, not least network streaming. All this makes for a slightly matter-of-fact sound from the 'GX70, in absolute terms – one that is by no means bad but just lacks raw emotion. For example, the pounding synthesiser bassline of New Order's World In Motion wasn't as dextrously handled as some of this amplifier's more minimalist, focused rivals can manage.
Its bigger and slightly more expensive SU-G700 M2 brother sounds obviously more impactful and spacious. When I reviewed it, there was a sense of it taking my loudspeakers by the scruff of their necks and shaking them. This newer and smaller Technics amp lacks such brio and is more genteel. It's a character trait that's evident across everything the SU-GX70 plays; it's always tidy, well-ordered and impressive but doesn't quite stir the soul. In fairness, considering the sort of system this amp might be asked to slot into – which may not be the last word in refinement – its smoothness could be a jolly good thing.
The new Technics SU-GX70 is less of a giant killer in the sonic stakes than its bigger brother, but focusing in on this is surely to miss the point. It still sounds very decent and is way better than the sort of budget all-in-one systems that prospective purchasers of this might be upgrading from. Although its manufacturer calls it a 'network amplifier', it's more of a 'one-box system' in its functionality and flexibility. Looked at this way, it offers an awful lot for the money and is actually tailored very well for a certain type of buyer who wants high-quality build, versatility and relative ease of use as much as decent sound. Whilst it might not be the greatest audiophile bargain in town, judged by these wider criteria, it is a sure-fire winner.
David started his career in 1993 writing for Hi-Fi World and went on to edit the magazine for nearly a decade. He was then made Editor of Hi-Fi Choice and continued to freelance for it and Hi-Fi News until becoming StereoNET’s Editor-in-Chief.
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