Within the app, you’ll find a relatively intuitive interface that lets you futz with tons of settings, choose inputs, and stream audio via services like Spotify, Tidal, Deezer, and others. You can add Favorites for quick access to a wide array of local and global radio stations or play directly from Spotify Connect, AirPlay 2, Chromecast, or Bluetooth. You can also stream hi-res audio files from a local server at up to 384 kHz/32-bit resolution or DSD up to 11.2 MHz.
The GX70’s spread of connection options is impressive and includes three digital inputs (two optical and one Coax), USB-B and USB-A, and good ol’ FM radio. Outputs include a front-facing headphone output, stereo speaker outs, and a preamp output for connecting a second amp or a powered sub. So yeah, you won’t run out of ways to play anytime soon.
If you prefer a more tactile means of control than the mobile app, the GX70’s long-wand remote harbors the majority of significant functions, though I wish it included backlighting. You won’t need it for TV control, though, as your TV remote lets you control power and volume when connected over HDMI ARC—just make sure to first adjust your TV’s audio output to PCM, or the amp will make horrible noises that could damage your speakers.
Elegant audio
While the SU-GX70’s truckload of features understandably get the lion’s share of attention, when it comes to performance Technics has delivered a clear and capable amplifier behind all that flashy tech. With an efficient power plant of 40 watts per channel for an 8-Ohm load, the amp should have no trouble powering most speaker sets, from bookshelves to towers.
I tested the GX70 with three different bookshelf pairs, including the Bowers & Wilkins’ 606 S3 (8/10, WIRED Recommends), Focal Theva (9/10, WIRED Recommends), and Polk Legend L100. Across all three models, the Technics provided crisp and clear audio with excellent definition, a precise and well-defined stereo image, and impressive balance across frequencies.
Coming from the Uniti Atom, which costs nearly double what you’ll pay for the SU-GX70, I understandably had to adjust my expectations. The Technics doesn’t offer the same body and dynamic sound in the midrange and bass, nor does it provide a soundstage as expansive or dimensional as the one Naim’s black box delivers. There’s a reason the Uniti Atom is an audiophile favorite, but you’ll pay for that pleasure and get fewer inputs and settings into the bargain. That said, the Technics’ sound profile is also a departure from my other main setup, KEF’s LSX-powered bookshelves.
The trait that really caught my attention when I connected the SU-GX70 is its brighter and more clinical delivery. That was especially noticeable with TV content, where the amp brought a more forward tone and some ramped-up sibilance, with “S” sounds seeming to jump out a bit more readily in light audio productions. I got used to the tighter tone over time, and the amp is an especially good pairing with Focal’s smooth and silky Theva speakers, which provide great clarity without ever sounding sharp. The snappier B&W 606 S3 created a less amicable partnership.
When connecting U-Turn’s Orbit Theory (9/10, WIRED Recommends) turntable (I’ll be auditioning a Technics SL-1500C-W next, so stay tuned), I noted a drop in dimensionality and warmth over the Naim system, but again that’s to be expected at this price, and I was impressed by how well the GX70 holds up for the money. Albums like Elton John’s Tumbleweed Connection sound sparklingly clear, complete with all the creamy goodness of his piano and an impressive collage of twangy instruments across the soundstage in songs like “Amoreena” and “Where to Now St. Peter?”
While it’s important to pick the right speaker pairing, namely those with smoother sound profiles from brands like KEF or Focal, the SU-GX70 is a fun and versatile system. Its sweet mix of clear and detailed sound and gobs of features and connection options make it an enticing stereo centerpiece for budding audiophiles.
