Technics - SU-GX70 Network Integrated Amplifier

A full-digital Grand Class amplifier with the whole network stack inside — Wi-Fi, Ethernet, Bluetooth, AirPlay 2, Chromecast, HDMI ARC, an FM tuner and a moving-magnet phono input — in a chassis 98mm tall.

The SU-GX70 is Technics’ answer to the whole-system-in-one-box question, and it answers it without giving up the amplifier engineering. The output stage is the same full-digital architecture as the SU-G700M2 and SU-R1000, with JENO Engine handling jitter and LAPC calibrating the amplifier against the actual loudspeakers you connect.

What it adds is everything else. Ethernet and dual-band Wi-Fi. Bluetooth 5.1. AirPlay 2 and Chromecast built in. An HDMI ARC output so a television can feed it directly and be controlled by the TV remote. Two optical and one coaxial digital input. A USB-A port on the front for a drive and a USB-B on the back for a computer. An FM tuner with thirty presets. And a moving-magnet phono input, which is not a given on a streaming amplifier.

There is a Pure Amplification Mode that cuts power to the network and HDMI circuits entirely, so that when you are listening to a record or a CD those sections are not sitting there generating noise inside the same box. A Twin Power Supply Circuit System keeps the power amplifier’s supply independent of everything else for the same reason.

Three honest notes about the published specification. First, the power rating: 40W into 8Ω and 80W into 4Ω, but measured at 1.0% distortion, where the SU-G700M2 and SU-R1000 are rated at 0.5%. The frequency response figures are also quoted at 4Ω rather than 8Ω. These numbers are not comparable across Technics’ own range, and it would be misleading of us to line them up as if they were.

Second, MQA. Technics’ US page says the MQA decoder is present; the owner’s manual’s detailed format tables do not list MQA anywhere. We cannot resolve that and we are not going to pick a side.

Third, Roon. Technics’ German press office announced that Roon Ready and TIDAL Connect were added to this model by firmware update. The US spec page has not been updated to reflect it. If Roon is why you are buying, tell us and we will confirm the firmware state of the unit before it leaves.

Features

• Full-digital amplifier: 40W + 40W into 8Ω, 80W + 80W into 4Ω, both at 1.0% THD
• JENO Engine jitter elimination and LAPC speaker-load calibration
• Dual-band Wi-Fi, Ethernet, Bluetooth 5.1, AirPlay 2 and Chromecast built in
• HDMI ARC output for direct television connection
• Moving-magnet phono input
• FM tuner with 30 presets
• Two optical and one coaxial digital input; USB-A front, USB-B rear
• Pure Amplification Mode shuts down the network and HDMI circuits during critical listening
• Twin Power Supply Circuit System isolating the power amplifier supply
• 98mm tall

Specifications

• Type: Network audio amplifier — a full-digital integrated amplifier with streaming, HDMI ARC, FM tuner and phono input
• Topology: Full digital amplifier
• Rated power output: 40W + 40W (1kHz, THD 1.0%, 8Ω, 20kHz LPF); 80W + 80W (1kHz, THD 1.0%, 4Ω, 20kHz LPF). Read the distortion condition: 1.0% here against 0.5% on the SU-G700M2 and SU-R1000. These figures are not directly comparable with those models
• Load impedance: 4–16Ω
• Frequency response, line: 20Hz–40kHz (−3dB, 4Ω)
• Frequency response, digital: 20Hz–80kHz (−3dB, 4Ω)
• Frequency response, phono MM: 20Hz–20kHz, RIAA deviation ±1dB, 4Ω. Note Technics quotes this model’s response figures at 4Ω where the SU-G700M2 and SU-R1000 are quoted at 8Ω
• THD: Only the 1.0% figure quoted with the power ratings is published
• Signal-to-noise ratio: Not published. Technics publishes no signal-to-noise ratio for any of its full-digital amplifiers — we checked the US page, the UK page, the catalogue and the owner’s manual.
• Damping factor: Not published. Technics publishes no damping factor for any of its full-digital amplifiers. A conventional damping-factor figure is arguably less meaningful for a switching output stage, but Technics does not say that either — the row is simply absent.
• JENO Engine: JENO Engine — Jitter Elimination and Noise-shaping Optimisation. A clock generator and re-clocking stage that Technics says reduces jitter across the entire frequency range. Jitter is timing error in the digital signal; left alone it smears detail, and it is the single most audible failing of an indifferent digital front end.
• LAPC: LAPC — Load Adaptive Phase Calibration. The amplifier sends a test signal through the actual speakers and cables you have connected, measures what comes back, and uses DSP to correct its own phase and frequency response toward that of an ideal amplifier driving that specific load. Most amplifiers are designed against an assumed resistive load; a real loudspeaker is nothing of the sort.
• Twin Power Supply Circuit System: A dedicated power supply for the power amplifier circuits, independent of all other circuits, to keep digital and network noise out of the amplification
• Pure Amplification Mode: A selectable mode that shuts off power to the network and HDMI circuits so they cannot introduce noise during playback
• Phono stage: Moving magnet only — there is no MC input. 2.0mV at 47kΩ, fixed. Gain is not published as a separate figure
• Line input sensitivity: 200mV / 23kΩ
• Digital conversion: Technics’ own full-digital / PWM architecture. No off-the-shelf DAC chip is used or named
• PCM support: WAV, FLAC, AIFF and ALAC up to 384kHz at 16, 24 and 32 bit (FLAC and ALAC limited to 16 and 24 bit); AAC to 96kHz, 16–320kbps; MP3 to 48kHz, 16–320kbps. USB-B is USB Audio Class 2.0, asynchronous, LPCM 32–384kHz
• DSD support: 2.8MHz, 5.6MHz and 11.2MHz over USB-A, USB-B (ASIO native and DoP) and network
• MQA: Disputed between Technics’ own sources. The US product page states the MQA decoder is present; the owner’s manual’s detailed format tables do not list MQA at all. We are reporting the conflict rather than resolving it
• Ethernet: 100BASE-TX / 10BASE-T
• Wi-Fi: IEEE 802.11a/b/g/n/ac/ax, 2.4GHz and 5GHz, WPA2. Note that Technics’ US product page prints the Ethernet value in the Wi-Fi row — an obvious copy error on their site. The figures here come from the owner’s manual
• Bluetooth: Version 5.1, Class 1 (4mW), A2DP and AVRCP, codecs AAC and SBC, approximately 10m line of sight. The version number appears in the manual only, not on the web page
• AirPlay 2: Yes
• Chromecast built-in: Yes
• Spotify Connect, TIDAL, Deezer, Qobuz, Amazon Music, internet radio: None of these is itemised in Technics’ own spec tables for this model, in contrast to the SA-C600 and SL-G700M2 which name them all. Chromecast built-in covers casting from those apps, but we are not going to claim native support Technics does not list
• Roon Ready: Added by firmware update per a Technics press release, which named the SU-GX70 alongside the SL-G700M2 and SC-CX700. TIDAL Connect was added in the same update. Neither is reflected on Technics’ US spec page. Ask us and we will confirm the firmware state of the unit before it ships
• DLNA: Digital Media Renderer supported, with the same format list as USB-A
• FM tuner: Yes, 87.5–108.0MHz with 30 presets. Note that the UK and EU version of this model also carries a DAB tuner; the US version is FM only
• USB-A: Front panel, mass storage playback to 2TB, FAT16/FAT32/NTFS, maximum 800 folders and 8,000 files, 5V/0.5A maximum output
• USB-B: Rear panel, USB 2.0 High Speed, USB Audio Class 2.0, asynchronous — a computer DAC input
• Control app: Technics Audio Center
• Inputs: LINE x2, PHONO (MM) x1, optical x2, coaxial x1, USB-A x1, USB-B x1, Ethernet, Wi-Fi, Bluetooth, FM antenna
• Outputs: PRE OUT x1, HDMI (ARC), headphone (6.3mm stereo)
• Headphone output: 6.3mm stereo, 5mW into 32Ω at maximum volume. From the owner’s manual; the web spec page gives no rating
• Speaker terminals: Technics’ own terminals table does not itemise the speaker outputs at all, listing only PRE OUT under analogue output. Bi-wiring is not published
• Dimensions: 430 x 98 x 368 mm (W x H x D)
• Weight: Approximately 6.6kg (14.6 lbs)
• Power consumption: 63W
• Standby consumption: Approximately 2.0W with network standby on; approximately 0.5W with it off. From the owner’s manual; absent from the web spec page
• Country of manufacture: Not published. Technics prints no country-of-manufacture statement on its product pages, specification sheets or owner’s manuals for this product — we checked all three. The owner’s manual lists Panasonic’s corporate address in Osaka, but a head office is not a factory and we are not going to present it as one.
• Warranty: Panasonic administers Technics warranty in the United States and the term varies by model rather than by product category. The SU-GX70 does not appear in Technics’ published US warranty table. Their other current integrated amplifiers, the SU-G700M2 and SU-R1000, are both listed at three years parts and labour. Ask us and we will confirm with Panasonic rather than assume. Technics states that product registration is not required and does not extend coverage. A dated sales receipt is required, coverage runs to the original purchaser, and the product must be purchased and serviced in the United States. Non-rechargeable batteries, antennas and cosmetic cabinet parts are excluded.