Onkyo TX-8390: A Stereo Receiver Built for Modern Systems

The Onkyo TX-8390 occupies an interesting place in the stereo market: it is a two-channel receiver that behaves in many ways like the hub of a modern living-room system. Rather than asking owners to choose between classic stereo sources and contemporary networked playback, it brings both into one chassis. Its documented feature set includes a substantial amplifier section, a built-in DAC, HDMI switching, phono support, subwoofer outputs, automatic acoustic calibration, app control, wireless streaming, Internet services and Zone 2 capability. That combination makes the TX-8390 notable not because it is a surround receiver, but because it applies many of the conveniences associated with AV receivers to a stereo format.

A two-channel receiver with serious system-hub ambitions

At its core, the Onkyo TX-8390 is a stereo receiver, not a multichannel home-theater amplifier. It provides two channels of amplification and four pairs of screw speaker terminals, allowing connection of A/B speaker configurations within the supported impedance ranges. For many listeners, that keeps the system architecture simple: two main speakers, optional subwoofer support, and a single component handling source selection, amplification and control.

The receiver’s amplifier section is built around a large high-current power transformer, audio-grade capacitors, phase-shift-free amplifier circuitry and a discrete transistor output stage. These are meaningful design choices in a stereo receiver because they relate to current delivery, circuit stability and the way the amplifier is intended to handle a wide frequency range. The published power ratings include 105 watts per channel into 8 ohms from 20 Hz to 20 kHz at 0.08% THD with two channels driven, as well as higher one-channel ratings into 6 ohms under different test conditions. For prospective owners, the important point is that Onkyo positions the TX-8390 as more than a compact convenience receiver; it is designed to drive conventional passive loudspeakers in a full-size hi-fi system.

The physical design also supports that impression. A 5 mm-thick extruded aluminum front panel gives the unit a more substantial front fascia than many lightweight all-in-one products. With dimensions of 435 x 174 x 383 mm and a weight of 11.8 kg, this is a standard-width component intended for an equipment rack, media cabinet or traditional stereo setup rather than a tabletop streaming niche.

AccuEQ brings room setup into stereo

One of the TX-8390’s most distinctive documented features is the inclusion of AccuEQ acoustic calibration. Onkyo originally developed AccuEQ for multichannel AV receivers, but here it is adapted for a stereo model. That matters because stereo systems are often placed in real rooms that are not acoustically treated, with speakers positioned around furniture, televisions, windows and walls.

AccuEQ measures speaker size and distance from the listening position, sets sound pressure levels, selects a subwoofer crossover and applies equalization. The practical value is not that it replaces careful speaker placement, but that it gives owners a built-in tool for integrating speakers and subwoofers more consistently. In a stereo receiver, automatic calibration is still relatively uncommon compared with AV receivers, so its presence helps distinguish the TX-8390 from more traditional analog-focused models.

Subwoofer integration is also supported by two subwoofer pre-outs and a specified subwoofer output level. The ability to let the receiver choose a crossover can be useful for listeners adding low-frequency reinforcement to bookshelf speakers, or for larger rooms where stereo speakers alone may not provide the desired bass extension. For owners who prefer a simpler signal path, Direct mode disables tone controls, while Pure Audio mode disables non-essential circuitry such as the display and analog video circuits.

Digital conversion and hi-res playback support

The TX-8390 includes an Asahi Kasei AK4458 DAC supporting digital-to-analog conversion up to 384 kHz/32-bit. It is followed by Onkyo’s VLSC filtering, designed to suppress impulse noise and ultra-high-frequency interference. In practical terms, this means the receiver is intended to serve not just as an analog amplifier, but as the main digital conversion stage for a networked audio system.

A wired LAN connection enables playback of hi-res files stored on computers and servers on the local network. Supported formats over LAN include MP3, WMA, WMA Lossless, FLAC and WAV up to 24-bit/192 kHz, AAC, Apple Lossless up to 24-bit/96 kHz, AIFF up to 24-bit/192 kHz, DSD up to 5.6 MHz in PCM conversion mode and LPCM. USB playback further broadens the format list with support for MQA, FLAC, WAV, ALAC, DSD, AIFF, WMA Lossless, MP3 and AAC.

For listeners with local music libraries, those format lists are important. They mean the receiver can sit at the center of a mixed system containing streaming services, stored hi-res files and external drives. Two USB ports are provided, including a front-panel port rated at 5 V/1 A and a rear port rated at 5 V/500 mA, which can be used for external storage devices and powering external devices.

HDMI makes it TV-friendly without turning it into an AV receiver

A major strength of the TX-8390 is its extensive HDMI provision. The receiver includes six HDMI 2.0a inputs with HDCP 2.3 support and two HDMI outputs, with Audio Return Channel support noted for TV integration. The HDMI ports support 4K video at 60 Hz, 3D, HDR, Dolby Vision, DSD file transfer and related functions. There is also 1080p-to-4K upscaling via HDMI.

This is significant for a stereo product because many music-first systems now share space with a television. A conventional integrated amplifier may require compromises when connecting a TV, game console, streamer or disc player. The TX-8390 instead allows several HDMI sources to be switched through a two-channel receiver, keeping the speaker system stereo while simplifying cabling. It is not presented as a surround processor, but it does provide the video connectivity many living-room stereo owners need.

Alongside HDMI, the receiver offers four line-level RCA inputs, an MM phono input, two optical digital inputs, one coaxial digital input, Ethernet, antenna connections and control ports including RI system bus, IR input and IR output. That spread allows it to accommodate a turntable, legacy analog components, digital transports, network sources and television-related devices in the same system.

Streaming, wireless audio and app control

The TX-8390 supports dual-band Wi-Fi on 2.4 and 5 GHz networks, Bluetooth 4.1 + LE with A2DP and AVRCP profiles, AirPlay 2, Chromecast built-in, DTS Play-Fi, FlareConnect and Sonos compatibility. It also supports services including Spotify, Amazon Music, TIDAL, Deezer and TuneIn, along with Internet radio. Voice control for audio playback is available through Google Assistant or Siri-enabled devices.

The breadth of streaming support is useful because households rarely standardize on one ecosystem. One person may use AirPlay 2 from an Apple device, another may rely on Chromecast-enabled apps, while a wider multiroom system may use DTS Play-Fi, Sonos integration or Onkyo’s own Controller app for iOS and Android. The receiver’s ability to participate in multiple platforms makes it easier to fit into an existing home rather than requiring a complete change of habits.

Multiroom use is also part of the design. The receiver includes Zone 2 line outputs and a separate Zone 2 DAC, enabling distributed digital and analog audio, including HDMI and SPDIF sources. FireConnect wireless technology support is documented for multiroom installation at 44.1 and 48 kHz sampling rates, with Onkyo Controller app grouping and playback control. For owners who want stereo in the main room and music elsewhere, this flexibility may reduce the need for separate source components.

Analog flexibility, phono input and external amplification options

The inclusion of an MM phono stage gives the TX-8390 a clear link to traditional stereo use. Owners of moving-magnet cartridges can connect a turntable directly without adding an outboard phono preamplifier. The receiver also includes a ground terminal, which is a practical requirement for many turntable setups.

For headphone listening, a 6.3 mm headphone output is provided, with a documented headphone amplifier rating of 80 mW into 32 ohms at 1 kHz and 10% THD. While that specification should not be overinterpreted, the full-size jack is a useful convenience on a component intended to serve as the main audio hub.

The TX-8390 also offers Pre-Amp Mode and Front Pre-Out connections for use with an external power amplifier. This is an important long-term flexibility feature: an owner can begin with the receiver’s built-in amplification, then later add a separate power amplifier while retaining the TX-8390 as a preamplifier, DAC, streamer and switching center. The same outputs can function as Zone 2 line outputs, adding another layer of system configuration.

Who the Onkyo TX-8390 is most suitable for

The TX-8390 is best suited to listeners who want a stereo-first system but need the connectivity of a modern entertainment hub. It makes particular sense in a living room where a pair of passive speakers is used for music, TV sound and multiple HDMI sources. It is also a strong conceptual fit for users with varied source habits: vinyl, network files, streaming services, Internet radio, Bluetooth, AirPlay 2 and Chromecast can all coexist in one component.

It will also appeal to owners who want room setup assistance without moving to a full AV receiver. AccuEQ, subwoofer crossover management and dual subwoofer outputs are practical tools for people placing speakers in normal domestic spaces rather than dedicated listening rooms.

It may be less appropriate for someone seeking a minimalist analog integrated amplifier with only a few inputs, or for a user who specifically needs multichannel surround decoding and speaker outputs for a full home-theater layout. The TX-8390’s strength lies in combining stereo amplification with extensive input, streaming and control functions, not in replacing a surround receiver for a multichannel system.

Conclusion

The Onkyo TX-8390 stands out as a stereo receiver designed for the way many systems are actually used today: two speakers at the center, but many sources feeding them. Its strongest documented qualities are its substantial two-channel amplifier architecture, AccuEQ room calibration, AK4458 DAC with VLSC filtering, broad hi-res file support, six HDMI inputs, phono stage, dual subwoofer outputs, streaming compatibility and Zone 2 flexibility. For listeners who want a traditional stereo foundation with TV integration, network playback, app control and multiroom options built in, the TX-8390 offers a notably complete and adaptable approach.