The NAD C658 is a DAC, preamplifier and BluOS streamer in one. The NAD C 658 is powered by the BluOS streaming platform, which was developed for the Bluesound family of devices, then opened up to other Lenbrook parent brands such as NAD, and subsequently licensed to others including DALI.
The platform and its accompanying BluOS app act as an access point for a range of music and radio streaming services, including Spotify, Amazon Music, Tidal, Deezer, Qobuz, HDTracks, Napster, TuneIn Radio and iHeartRadio. It also opens the door to local and online music, supporting files up to 32-bit/192kHz and the MQA container, with over 250,000 tracks in the collection indexable.
The platform offers connectivity with any other BluOS player, and thanks to a recent update, it now boasts an additional connectivity option – via AirPlay 2 for multi-room streaming and streaming from Apple devices. Available for iOS, Android, Windows and Mac OS smartphones, tablets and computers, it sets a new standard for streaming platforms alongside Naim and Linn.
The BluOS app is easy to navigate, with a drop-down sidebar menu listing sources and services, as well as links for quick access to playlists and content you’ve set as favourites or presets. It’s a well-designed and robust app; even switching from one music service to another or to a local library is seamless.
In addition to BluOS as the heart of the NAD C 658, the player has many other advantages. In particular, it supports bidirectional Bluetooth aptX HD, which ensures the transmission of high-quality audio from the NAD to a pair of wireless headphones and allows you to receive tracks via Bluetooth from a smartphone or other Bluetooth-compatible source.
In addition, the NAD player can be used as the core of a multi-source system, since it is equipped with digital inputs, including two optical, two coaxial and one USB (the signals from which are fed to a 32-bit ESS Sabre DAC), as well as analog – two RCA inputs and an input for an MM phono stage, which is useful for connecting a turntable.
Understanding that technology and standards in the audio industry are constantly being updated, NAD made sure that the NAD C 658 can easily be adapted to future changes thanks to the modular design typical of the brand.
All of the main digital circuitry is upgradeable and replaceable, and for added functionality there are two dedicated slots, one of which can accommodate an existing NAD HDMI module with 4K pass-through support, making it easier to hook up a gaming console, Blu-ray player or set-top box, for example.
Another bonus is Dirac Live auto-calibration. This room-tuning technology, also used in the NAD M10 and some other surround sound systems, tests the acoustics of the room and optimizes the unit accordingly. It’s rare in two-channel units, which is a shame.
The calibration process is simple: connect the included microphone with a USB adapter to the NAD C 658, download the Dirac Live app and follow the instructions; for multiple measurements, place the microphone at different points around the listening position.
The app will analyze the frequency response of your room and generate a sound filter that you can save to your smartphone. The process takes about 20 minutes, but given the amount of customization, you may need to spend more time experimenting.
The Dirac Live auto-calibration system proved its worth in our testing, making the sound more open and alive. Even before correction, Muff’s electronic jazz track Ufofka impresses with its clarity and precision of fine detail in the spacious soundstage, but after applying the app’s filter, it’s even better. The cacophony of simultaneously playing sounds—crazy drums, sharp trumpets, melancholy strings—has even more space to move and interact.
In our opinion, the only downside to this streamer is its appearance. The NAD C 658 doesn’t look like a high-end system component; its matte finish and asymmetrically placed plastic controls are out of place at this price point.
The two screw-in antennas for dual-band Wi-Fi and Bluetooth don’t help the aesthetics either, although the central screen is useful for checking track information without having to take your phone out of your pocket. And of course, NAD’s build quality is beyond reproach.
The plain black plastic remote control isn’t particularly classy, and many will prefer a smartphone app, but you can grab any remote you have and use it to control the NAD player using the IR learning feature.
NAD C 658 Specifications
ESS Sabre DAC with MQA support.
BluOS operating system.
Dirac Live audio correction.
Supported formats: MQA, WAV, FLAC, AIFF (AIF, AIFC), MP3, AAC (M4A, MP4), WMA, OGG, ALAC (M4A), WMA-L).
Streaming services: CALM Radio, iHeartRadio, Radio Paradise, Slacker Radio, TuneIn, Deezer, Groove, JUKE, Murfie Napster, Qobuz, Spotify, Tidal, WiMP.
Audio inputs: MM Phono, 2 x Line Inputs, 2 x Optical Inputs, 2 x Coax Input.
Audio outputs: Balanced Preamp Output, RCA Preamp Output, Subwoofer Output
Gigabit Ethernet (RJ-45), Wi-Fi a/c/n dual-band, two-way Bluetooth aptX HD.
Additional inputs: 1 USB port, Trigger Out/In, IR (mono jack 3.5), 2 x MDC slots for upgrade.
Built-in Hi-Fi headphone amplifier.
Control using Russian-language applications for Android and iOS, as well as via PC, Mac, Crestron, RTI, Control4, iridiummobile, etc.
Learns IR commands from any remote control.
Also works as part of a multi-room system with other Bluesound, NAD and Dali devices (with the BluOs operating system).
Size 435 x 100 x 405 mm
Weight 10.1 kg
