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Reviews of Attainable Hi-Fi & Home-Theater Equipment

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Reviewers' ChoiceMea culpa

I’ve been at this reviewing gig for a while now, and save for the odd wrinkle with a couple of products, I’ve never committed a faux pas, such as returning a product damaged or missing any of its accessories -- until now.

In mid-2018, Technics’ SU-G700 integrated amplifier-DAC arrived on a shipping pallet with a pair of the Japanese company’s SB-G90 loudspeakers. (I reviewed the SB-G90s in October 2018.) I unboxed both products immediately but, already loaded up with other gear to review, it was a while before I could spend quality time with them. When, last November, I at last sat down to start listening to the SU-G700, I realized that its remote-control handset wasn’t in the basket where I keep the remotes and controllers for review samples and my own reference gear. I searched the basement, found the amplifier’s box, and within it the batteries for the remote, still wrapped in plastic. Then, to my horror, I saw that the plastic bag for the remote had been ripped open, but the remote was nowhere to be found. I looked at the picture of the remote in the SU-G700’s owner’s manual, but it didn’t look familiar. I can only assume that, months earlier, I’d unpacked the remote along with the amp itself, and somehow misplaced it.

Technics

Mortified, I called Doug Schneider, SoundStage!’s founder and publisher, and asked if, in his 20 years of reviewing, he’d ever done anything similar.

All I heard in response was a deadpan “No.” Well, then.

Dear Technics: I’m incredibly embarrassed, and apologize for my gross incompetence.

But that’s my last apology regarding the SU-G700.

Details

The SU-G700 is, to my eyes, a beautiful piece of electronics, and not just for the price ($2500 USD). It measures 17”W x 5.9”H x 16.9”D and weighs 27.2 pounds. Its bottom panel is a 2mm-thick steel plate, while the aluminum inner chassis and front panel are respectively 1.2mm and 7mm thick. Inside, the SU-G700 is partitioned to keep its input, output, and power-supply circuits isolated from one another. Dominating the front panel, behind a wide, thick pane of glass almost as wide as the faceplate itself, are two VU meters doused in pale white light with a bluish tint. VU meters of any kind are cool, and I really like Technics’ implementation. The only other adornments are all above this window: a power button and 6.5mm headphone jack at top left, a large, brushed-aluminum volume control at center, and, at top right, the source knob and a small screen that displays the active input, setting info, and signal sample rate.

While the SU-G700’s size and price might lead you to think it has a class-AB amplifier, it’s a true digital amplifier. Using Technics’ Jitter Elimination and Noise-shaping Optimization (JENO) circuitry, the SU-G700 operates entirely in the digital domain, from input stage to speaker terminals. Incoming PCM and DSD signals are converted to a pulse-width modulation (PWM) signal by the switching output stage, obviating the need for a traditional delta-sigma DAC. The JENO engine is a key component in the signal chain, using a battery-driven clock generator (instead of the main power supply, for maximum isolation and noise suppression), a sample-rate converter, and a PWM modulator. Volume control, too, is handled entirely in the digital domain. Combined with a bespoke, hybrid switch-mode power supply -- which, Technics argues, is superior to a traditional switching power supply thanks to its fixed switching frequency -- and a linear regulator to stabilize the output voltage, this circuit topology is ideal for digital sources. The discrete headphone amplifier, meanwhile, is a class-AA design that uses a pair of op-amps: one for voltage, one for current.

Technics

Out back, the SU-G700 offers five digital inputs: four S/PDIF connections (two optical, two coaxial) and one USB. The S/PDIF connections can accept signals of resolutions up to 24-bit/192kHz, while the asynchronous USB input can handle up to 32/384. There’s also a USB Type-A port for firmware updates, and a trigger connection. On the analog side, the Technics has a preamplifier output, a line output, a moving-magnet phono stage, and two RCA inputs, one configurable as a main input to allow its use as a stereo power amplifier. All analog inputs are routed through a Burr-Brown PCM1804 analog-to-digital converter, which means that any analog signal is converted twice -- from analog to digital, then back to analog -- before being passed on to the speaker terminals with their beefy five-way binding posts. There’s also the usual IEC power inlet.

That misplaced remote control is a generic-looking, multifunction model with volume, muting, and source-selection controls, as well as buttons for operating other Technics components, such as the matching ST-G30 music server. It also lets the user navigate the SU-G700’s various settings; e.g., dimming the power meter and display, digital tone controls, and Auto-Off. The SU-G700’s best party trick is delivered via a button labeled LAPC, for Load Adaptive Phase Calibration. Press this and the SU-G700 produces several minutes’ worth of test tones through whatever speakers are connected to it, then corrects the frequency response and phase, all via DSP. The beauty of this approach is that Technics’ DSP tailors the SU-G700’s output to the specific speakers used. When I realized that, because I’d lost the remote, I wouldn’t be able to try LAPC, my heart sank. So I did all of my listening without once engaging LAPC. But even without it, I was deeply impressed with what I heard from the SU-G700 -- if LAPC works as advertised, then the SU-G700 should sound even better.

Technics

Spec-wise, there’s not a lot to go on. Technics says that the SU-G700 produces 70Wpc into 8 ohms or 140Wpc into 4 ohms, and that its THD measures a rather high 0.5% when fed a 1kHz signal at rated power into each load. They also specify that the amp is compatible with speakers of 4 to 16 ohms -- presumably, it wouldn’t be the best match for super-low-impedance designs whose loads drop to 2 ohms or below.

Setup

Setup was dead easy. I installed the SU-G700 in my system with minimal fuss. Its included manual is straightforward and easily digestible, and other than that elusive remote control, the SU-G700’s only accoutrement is its power cord. I downloaded and installed the Windows-only driver from Technics’ website to my Intel NUC music server, which serves as my Roon Core. I plugged the SU-G700 into the NUC via a DH Labs Silver Sonic USB link, and Roon quickly identified it. I hooked up a Google Chromecast Audio to one of the Technics’ optical inputs so that I could stream Spotify content using Spotify Connect, and ran AudioQuest Rocket 33 banana-terminated speaker cables from the SU-G700 to my reference KEF LS50 stand-mounted speakers and, for long spells, Scansonic’s M-40 floorstanders.

I also briefly hooked up Benchmark Media Systems’ DAC3 HGC digital-to-analog converter to one of the Technics’ analog inputs, using a Dynamique Audio Shadow RCA cable, to verify that it worked as advertised, but quickly moved on: Having a digital signal converted to analog by the Benchmark, then converted back to digital by the Technics, and finally back to analog again at the amp’s speaker terminals, just doesn’t make much sense. Nonetheless, I’m sure that anyone with an older CD player, tape deck, or receiver would appreciate the convenience of the dual RCA inputs. I wasn’t able to test the phono input -- I’m not a vinyl guy -- but again, the inclusion of a moving-magnet phono stage will greatly appeal to LP fans. Finally, I played a couple songs through the SU-G700’s competent headphone amp using my trusty NAD Viso HP50 headphones and liked what I heard; Technics didn’t mail it in, so it’s a nice option to have. I did most of my critical listening via Roon and the Technics’ USB input.

Technics

If you’re wondering about the SU-G700’s lack of a network input, Technics offers a stablemate, the SU-G30 network audio amplifier -- while it lacks the SU-G700’s epic power meters, produces slightly less power (50Wpc into 8 ohms, 100Wpc into 4 ohms), and costs a lot more ($3999), it does include a raft of streaming and wireless support, including MQA compatibility.

Sound

The SU-G700 sounded fantastic. Digital amps, whether pure digital amps like this one or the more common class-D designs, have a reputation for sounding superclean but thin through the all-important midrange, with an edgy treble. While the Technics didn’t fully avoid this generalization, I was taken aback by just how engaging and transparent its sound was, even on the heels of the Hegel Music Systems H590 ($11,000) and TEAC NR-7CD ($4999) integrated-DACs. It offered a high proportion of the sound quality of those pricey all-in-ones, at only a fraction of the cost.

With my KEF LS50s in play, I cued up “High Hopes,” from Panic! at the Disco’s Pray for the Wicked (16-bit/44.1kHz FLAC, Fueled by Ramen/Tidal), and ratcheted up the volume. Between the high-school-marching-band trumpets and lead singer Brendon Urie’s voice at the beginning of the track, I felt I was blown back into the center seat of my sofa by the SU-G700’s dynamics and low-level detail. This hugely popular cut has little dynamic range, so at high volumes the upper midrange was a bit screechy. Yet despite the KEFs being only 85dB efficient, the SU-G700 remained entirely composed, sounding far more powerful than its 70Wpc spec might suggest. The brassy, metallic sound of the trumpets was delightfully bombastic and as clear as I could want, and Urie’s infectious chorus had solid center-fill between the KEFs. There’s not a lot of bass in this track, but the kick drum had solid definition allied to satisfying weight. The Technics was not the least bit shy.

Technics

In “We Will Rock You (Raw Sessions Version)” (16/44.1 FLAC, Hollywood/Tidal), a B-side version of their classic tune, Queen gees-up for the first 30 seconds or so. The kick drum sprang from the left channel with vigor, as various band members murmur about. The melody goes silent for a moment, before Freddie Mercury belts out the chorus. The SU-G700 was very quiet -- quieter than my far more expensive Hegel H590 -- and I was able to hear this old (1977) recording’s noise floor with ease. Moreover, Mercury’s naked vocal popped from the center of the soundstage with such tonal color and density that I played it a dozen times just so I could take in all its detail.

The Technics’ sound was also spacious -- its soundstage was huge, but not unnaturally so, and was supercoherent to boot. I effortlessly picked out Roger Taylor’s drums, and loved how the sound of them reverberating around the recording studio was transported into my listening room. I also loved hearing Mercury mutter, “Blood on your face -- big disgrace” before Taylor utters “One, two, three, fouhhh” and his massive kick-drum thwacks officially begin the song. It was impressive to hear how the SU-G700 layered Mercury’s voice so clearly forward of the rest of the mix, producing an illusion of three dimensions that I’ve rarely heard at this price. I found that if I fed it good recordings, it replied in kind. When I piped in garbage . . . well, you know.

Wanting to challenge the SU-G700 with demanding, well-recorded orchestral music, I turned to Abel Korzeniowski’s original soundtrack for the film W./E. (16/44.1 FLAC, Interscope/Universal). Track 1, “Charms,” is a sweeping, romantic piece that features a spot of call-and-response between a solo violin in the left channel and a cello in the right, and wave after wave of the main theme in the orchestral strings. The violins were wonderfully extended, remaining smooth even as I jacked up the volume, with nary a hint of glassiness or hardness -- something I’ve come to brace myself for with digital amps. Not this one. In fact, there was even a slight golden quality to Korzeniowski’s strings that took me by surprise. With plenty of texture and a hint of treble sweetness, the Technics amp tactfully walked the thin line between the archetypes of digital and analog sound, and in many ways exhibited the strengths of both. Punctuating all of this were the tinkling chords of a harp in the left channel, each strummed string ringing through with precision and delicacy. The Technics’ handling of “Charms” was so engaging and musical that my mind’s ear flitted back and forth between taking in the orchestration as a whole and focusing on the various sections and individual instruments. TEAC’s NR-7CD integrated amplifier-DAC-CD player ($4999) reproduces “Charms” more forensically, with greater attention to detail and a sharper overall sound, at the expense of flesh and blood -- the descriptor mechanical comes to mind. I heard more through the TEAC than through the Technics, but felt less.

201903 technics detail2

Finally, Daft Punk. Their Random Access Memories (16/44.1 ALAC, Columbia) must surely go down as one of the decade’s best albums, and its final track, “Contact,” is a standout. The SU-G700 had little difficulty playing this anthem very, very loudly through my KEF bookshelf speakers, so take its specified output of 70Wpc into 8 ohms with a big grain of salt. The bass line was robust, the drums deliciously full and ripe, the hi-hat cymbals shimmering healthily. Through it all, the SU-G700 never compressed or turned bright through the treble. Even the introductory spoken passage -- a recording of Captain Eugene Cernan from the 1972 Apollo 17 moon mission -- felt supple and tangible. Broadly speaking, I was startled to hear how reined-in the treble extension was with this cut, given how prominently it featured in the aforementioned Panic! at the Disco and Abel Korzeniowski tracks. For better or worse, the SU-G700 most definitely preserved the intent of the original recording.

Comparison

When I reviewed NAD’s M32 DirectDigital integrated amplifier-DAC in, I was blown away by its build quality and performance. The M32 costs $1499 more than the Technics SU-G700, and that buys you a far more sophisticated case and visual design, even if it forgoes old-school power meters. The NAD is similar to the Technics in terms of inputs: MM phono stage and two more analog, and the usual digital complement of USB, TosLink, and coaxial. There’s even a headphone output. The M32 is far more potent, its digital amplifier producing 180Wpc into 8 or 4 ohms.

The NAD produces a pristine, immaculate sound so devoid of noise or hash that it’s almost startling. The Technics sounded quite similar while offering about 90% of the NAD’s performance quality in most metrics. But while the M32 can position musicians on a soundstage with millimetric precision, the SU-G700 was a bit more diffuse. And while the Technics couldn’t match the NAD’s incredible timing, this counterintuitively resulted in a more subjectively pleasing sound -- transients weren’t as razor sharp, and voices weren’t as aggressive in attacks and decays as through the M32. Whatever small concessions the Technics made to the NAD in precision and rhythm, it made up for with a slightly fuller, more natural sound.

Technics

Parasound’s Halo Integrated integrated amplifier-DAC ($2495 when available, since replaced by the Halo HINT 6 at $2995), was an altogether different proposition. The class-AB Halo produced 240 or 160Wpc into 4 or 8 ohms, and was a far more traditional analog amplifier design, albeit one with terrific flexibility. The Halo’s DAC board included USB, TosLink, and coaxial inputs, while on the analog side there were no fewer than six inputs: five RCA, one XLR. In addition, it had an MM/MC phono input, two subwoofer outputs (RCA and XLR), and a built-in subwoofer crossover. The Halo Integrated was as complete a one-box solution as anyone was likely to find for $2495.

And its sound was beguiling; in fact, the Halo Integrated didn’t sound like anything. It’s still, arguably, the most neutral amplifier I’ve ever heard. Even after months of listening to the Parasound through a variety of speakers, I couldn’t identify any signature that it was imposing on my music collection.

In that sense, the SU-G700 sounded far more urgent and up on its toes: voices popped with greater urgency, brass and stringed instruments had more bite, and the overall sound was more airy. The Technics is more my speed -- the Parasound’s ruthless neutrality could make it sound a little boring. Moreover, in terms of transparency of sound and industrial design -- the Halo was well-built, but looked as if it hailed from 1999 -- the Technics amp edges it.

Conclusion

Technics’ SU-G700 is a lovely, lovely integrated amplifier-DAC, and I had more fun with it than I’ve had with any other amp I’ve reviewed in the past two years. Its styling respects the Japanese company’s history while still looking cool -- especially those big, blue-tinted power meters. While its digital amplifier circuit is cutting-edge, its inclusion of analog RCA and moving-magnet phono inputs makes it more flexible than you might expect, even if doing so requires the uncommon step of converting all analog signals to digital and back again.

Technics

But its sound -- dynamic, visceral, highly resolving -- was exemplary, and a mere stone’s throw away from that of far more expensive gear. Nor did its resolving abilities come at the expense of midrange body or delicacy. As long as you don’t need a ton of power, the SU-G700 should be at the top of your list for an integrated amp at the $2500 price point. It’s an easy Reviewers’ Choice, and an early contender for Product of the Year.

. . . Hans Wetzel
hansw@soundstagenetwork.com

Associated Equipment

  • Speakers -- KEF LS50, Scansonic M-40
  • Earphones and headphones -- NAD Viso HP50, PSB M4U 4
  • Integrated amplifier -- Hegel Music Systems H360 and H590, TEAC NR-7CD
  • Digital-to-analog converter -- Benchmark Media Systems DAC3 HGC
  • DAC-headphone amplifier -- Oppo Digital HA-2SE
  • Sources -- Intel NUC running Roon with Tidal HiFi, Qobuz Studio
  • Speaker cables -- AudioQuest Rocket 33, DH Labs Q-10 Signature, Dynamique Audio Caparo
  • Analog interconnects -- Dynamique Audio Shadow RCA, Nordost Blue Heaven LS XLR
  • Digital link -- DH Labs Silver Sonic USB
  • Power conditioner -- Emotiva CMX-2

Technics SU-G700 Integrated Amplifier-DAC
Price: $2500 USD.
Warranty: Three years parts and labor.

Technics
Panasonic Corporation of North America
Two Riverfront Plaza
Newark, NJ 07102-5490
Phone: (201) 348-7000

Website: www.technics.com