NAD C 658
NAD C 658
NAD C 658

NAD C 658: DAC, preamp, and BluOS streamer all in one

The NAD C658 is a DAC, preamp, and BluOS streamer all in one. The NAD C 658 runs on the BluOS streaming platform, which was developed for the Bluesound family of devices, then opened up to other brands from parent company Lenbrook – such as NAD – and subsequently licensed for production by others, including DALI.

The platform and its accompanying BluOS app serve 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/192 kHz and MQA container, while more than 250,000 tracks from the collection can be indexed.

NAD C 658 5.jpg

The platform allows pairing with any other player in the BluOS ecosystem, and thanks to a recent update, boasts another connection option – via AirPlay 2 for multi-room broadcasts and streaming from Apple devices. Available for smartphones, tablets and computers running iOS, Android, Windows and Mac OS, the app joins Naim and Linn in setting a new standard of excellence for streaming platforms.

The BluOS app is easy to navigate, with a sidebar drop-down menu listing sources and services, as well as links for quick access to playlists and content you’ve selected as favorites or presets. This is a well-designed and reliable application; even switching from one music service to another or to your local library is seamless.

NADC658-03w 2.jpg

In addition to BluOS as the “heart” of the NAD C 658, the player has many other advantages. Most notably, it supports aptX HD bidirectional Bluetooth, which delivers 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-enabled source.

In addition, the NAD can be used as the core of a multi-source system, with digital inputs including two optical, two coaxial and one USB (feeding to the ESS Saber’s 32-bit DAC), as well as two analogue inputs. RCA inputs and an input to a MM phono preamplifier, which is useful for connecting a vinyl player.

Recognizing that technology and standards in the audio industry are constantly evolving, NAD has ensured that the NAD C 658 can easily adapt to future changes thanks to the brand’s signature modular design.


All of the core digital circuitry can be upgraded and replaced, and there are two dedicated slots for added functionality, one of which can be connected to NAD’s existing HDMI module with 4K pass-through support, making it easier to connect, for example, a gaming console, Blu-ray player or set-top box.

Another bonus of the player is Dirac Live auto-calibration. Also used in the NAD M10 and some other surround sound systems, this room-based component-tuning technology tests room acoustics and optimizes the device’s performance accordingly. It is rare in two-channel devices, which is very annoying.


The calibration process is simple: connect the included microphone with USB adapter to the NAD C 658, download the Dirac Live app and follow the instructions; To make 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, however, given the amount of settings, you may need more time to experiment.


Dirac Live’s auto-calibration system proved its worth in our testing, delivering a more open and lively sound. Even before the correction, the electronic jazz composition Ufofka by Muff admires the purity and accuracy of small details on a voluminous musical stage, but after applying the filter generated by the application, it is presented even better. The cacophony of simultaneous sounds—frantic drums, strident trumpets, melancholy strings—is given even more space to move and interact.

In our opinion, the only drawback of this network player is its appearance. The NAD C 658 doesn’t look like a high-end system component; Its matte finish and asymmetrically placed plastic knobs aren’t too 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 screen in the center is useful for viewing track information without having to take your phone out of your pocket. And, of course, the quality of NAD’s design is beyond doubt.

A simple black plastic remote control does not look very presentable, and many will prefer an application on a smartphone; But you can take any one you have in your home and use it to control your NAD player using the IR learning function.

Specifications of the NAD C 658

ESS Saber DAC with MQA support.
Operating system BluOs.
Dirac Live audio correction system.
Format support: 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.
Also works as part of a multi-room system with other Bluesound, NAD and Dali devices (with BluOs operating system).
Dimensions 435 x 100 x 405 mm
Weight 10.1 kg