About The NAD C658 DAC, Pre-Amplifier
The NAD C 658 is a versatile component. It is a DAC, Music Streamer and stereo Preamplifier all rolled into one neat package. Yes, it is part of NAD's Classic Series of components which have an enviable reputation for giving music lovers more enjoyment for less money. If you want a solid block of hand–crafted aluminium with gold plated accents you'll need to look elsewhere. If you want state-of-the-art award-winning performance and features in a sturdy no-nonsense package then you have the right address.
Let's face it, the way we enjoy music continues to move away from just physical media aka LPs and CDs and to what we call music streaming. And the NAD C658 is no ordinary music streamer, but absolutely a high-resolution network music streamer and from input to output. It features the ESS Sabre 32-bit DAC, one of the best performing DACs on the market today with its 118dB Dynamic Range and incredibly low jitter spec.
It's Also A Pre-amplifier: You've probably got a variety of other components that you want to use and the C658 has plenty of inputs including a dedicated phono stage. All preamp functions are executed in the digital domain including the same wide range non-truncating digital volume control used in the other NAD Masters Series components. This offers an incredibly short analogue signal path that, rather uniquely, is identical for all volume settings. Sophisticated active power supplies provide super clean voltages to all circuits to keep noise and distortion at the edge of measurability.
The C 658 has incorporated these fundamental truths to create an entirely new type of component that combines a Network Streamer, a state-of-the art DAC, and many aspects of the traditional Preamplifier into a single highly cost effective package. And thanks to NAD's exclusive Modular Design Construction, it will keep pace with the latest technology, not yet introduced, but inevitably coming in the future. In fact, an optional HDMI 4k switcher module is available now allowing the best sound from any of the many HDMI sources available (like game consoles and video Set Top Boxes).
While the NAD C 658 immediately replaces (or adds) your Streamer, DAC, and Preamp, it also adds many new features you may not be aware of, like a Bluetooth aptX HD transmitter to use with your wireless headphones. The highly flexible outputs allow for a true balanced connection to powered speakers or amplifiers. Single-ended connections for amplifiers and subwoofers are also provided and include an adjustable subwoofer crossover executed perfectly in the digital domain.
Bluetooth aptX HD: The NAD C 658 features two-way wireless Bluetooth capability that is powered by aptX HD for the highest possible sound quality available. aptX HD supports 48kHz/24-bit LPCM audio over a Bluetooth wireless connection for a "better-than-CD" listening experience. The C 658 can act as a Bluetooth Receiver or Bluetooth Transmitter (but not both at the same time). The Bluetooth Receiver and Transmitter modes are only accessible via the BluOS App. You can pair multiple devices with the BluOS Streaming DAC, but only one device can be connected and used at a time (the BluOS Controller app must be used for pairing). The NAD C 658 has a Bluetooth wireless range of approximately 10 meters.
BluOS Enabled: Also on board is BluOS, the most sophisticated high res streaming system available. BluOS natively supports over 15 streaming music services and indexing of over 250,000 tracks from local network sources. The C 658 becomes a node in the BluOS ecosystem and uses your home's wired or wireless network to connect multiple Bluesound products and play your music in perfect sync, or different music simultaneously, anywhere in your home. BluOS can wirelessly transmit lossless music up to 24-bit/192kHz at ultra-fast speeds with no lag and zero loss in sound quality.
BluOS Controller App: The free BluOS Controller app (for Apple iOS 9.3-up, Android OS 4.1-up, Windows XP-up, and Mac OS X 10.7-up) turns your mobile device or computer into a full-featured wireless remote control for the NAD C 658 and the BluOS wireless multi-room audio system. The BluOS Controller app on your compatible device uses your home's WiFi network to connect with Bluesound devices, so you can play all the music you love anywhere in your home for a wireless multi-room music experience. Get on-demand access to your music libraries on your home network, stream live Internet radio from almost any place in the world, or listen to one of the many music services available on Bluesound, all from the palm of your hand with the easy-to-use BluOS Controller app.
Alexa Compatible: The NAD C 658 BluOS Streaming DAC will support Amazon Alexa and voice control through an over-the-network firmware update (now available). Using an Amazon Alexa enabled device (sold separately), you can use your voice to explore music services, select presets, adjust volume levels, switch up songs in different rooms, or even group your Bluesound components together and play your music in perfect sync throughout the house. Each Alexa voice command will need to start with the phrase "Alexa, ask Blue Voice to" or "Alexa, Tell Blue Voice to". Alexa Skills for BluOS will need to be setup through the Amazon Alexa app on your Apple iOS or Android device.
High Resolution Audio: High-resolution audio tracks are either 24-bit/96kHz or 24-bit/192kHz, and contain up to 6.5x more data than standard CDs, letting you hear all the detail of your favourite music in superior quality. With full support for hi-res audio, you can stream WAV, FLAC, ALAC, AIFF, WMA-Lossless, MQA music files over your home's WiFi network or directly from a connected USB mass storage class device. Bluesound also supports compressed music files such as MP3, AAC, WMA and OGG. Bluesound has been designed to work with today's larger music collections, and has indexed libraries up to 200,000 songs in demonstrated practice (this will depend on the music's metadata & artwork). Bluesound also offers gapless playback by default for all supported file music types.
Master Quality Authenticated (MQA): This is a revolutionary end-to-end technology built into every BluOS Enabled amplifier to capture and deliver MQA music to your speakers in the purest quality. All BluOS Enabled players and systems include a powerful decoder and audio renderer for the millions of MQA encoded songs, The MQA logo shown in the BluOS app indicates that the unit is decoding and playing an MQA stream or file, and lets you know that you are hearing exactly what the artist recorded and approved in the studio.
Dirac Live Room Correction: The NAD C 658 employs Dirac Live Room Correction software that delivers optimised sound quality for your home theatre system. The built-in Lite version of the computer software (for Windows or Mac), with the option to upgrade to a full-featured version, measures the acoustic performance of the system within the listening room and optimises playback performance to provide the most transparent music reproduction possible. The setup process is automated and very simple, giving you the control they need to precisely tune for the best results. With Dirac Live, you can build the perfect listening environment that corrects for both the timing and colourations in sound using the supplied microphone and its powerful computer software.
Note: The C 658 will include a license for Dirac Live with the option for advanced users to upgrade to a Dirac Live Full Frequency version.
NAD C658 Review
"NAD's C 658 offers many features and functions in an affordable and good-sounding package. This streaming DAC, operated via the BluOS app or remote control, has a phonostage, analog inputs, subwoofer outputs with configurable crossover, full analog and digital preamplifier functions, and Dirac Live DSP room correction. This last feature can greatly improve the sound, particularly in problematic listening rooms. The C 658's sound is excellent, with tuneful bass and a spacious soundstage." The Absolute Sound Editors' Choice Awards 2023
Our Take
It is, big breath, an analogue (line & MM phono) preamplifier for use directly into a power amp such as the wonderful NAD C 298, it is a stand alone high resolution digital to analogue convertor (DAC). It offers on-board DIRAC live room correction so no matter what your listening room is like, a system based around the C 658 can be custom tailored to suit. And it has the BluOs streaming platform built-in so you can stream high resolution music through your system and also to other BluOs enabled devices around your home, such as the full range of Bluesound streaming components and speakers.
So it has the functionality aspect well and truly sorted. Fortunately, as our very own Simon Finch would tell you, it is also a "tidy little jigger" sound wise, with a well balanced & detailed musical output that is strong on dynamics and with a pleasing sense of naturalness that treats all types of recordings well. Oh, and the price, considering everything you get, is frankly unbelievable. Top marks NAD.
Main Features & Specifications
- Product Description: Analogue & Digital Stereo Pre-Amplifier
- Digital To Analogue Convertor (ESS Sabre DAC)
- BluOS Network Streamer with MQA Decoding
- Dirac Live Room Correction
Line Input, Pre-Out
- THD (20Hz – 20kHz): <0.005% at 2V out
- Signal-to-Noise Ratio: >106dB (IHF; A-weighted, ref. 500mV out, unity gain)
- Channel separation:
- >80dB (1kHz)
- >70dB (10kHz)
- Input impedance (R and C): 22 kohms + 100pF
- Maximum input signal: >4.5Vrms (ref. 0.1% THD)
- Output impedance: Source Z + 240 Ohm
- Input sensitivity: 93mV (ref. 500mV out, Volume maximum)
- Frequency response: ±0.3dB (20Hz – 20kHz)
- Maximum voltage output – IHF load: >4.5V (ref. 0.1% THD)
- Tone Controls:
- Treble >±7.0dB at 20kHz
- Bass: ±7.0dB at 60Hz
- Balance: -10dB
Phono Input, Audio Pre-Out
- THD (20Hz – 20kHz): <0.01% at 2V out
- Signal-to-Noise Ratio:
- >84dB (200 Ohm source; A-weighted, ref. 500mV out)
- >76dB (MM cartridge source, IHF; A-weighted, ref. 500mV out)
- Input sensitivity: 1.44mV (ref. 500mV out, Volume maximum)
- Frequency response: >±0.3dB (20Hz – 20kHz)
- Maximum input signal at 1kHz: >80mVrms (ref. 0.1% THD)
Line Input, Headphone Out
- THD (20Hz – 20kHz): <0.005% at 1V out
- Signal-to-Noise Ratio: >110dB (32 Ohms loads; A-WTD, ref. 2V out, unity gain)
- Frequency response: ±0.3dB (20Hz – 20kHz)
- Channel separation: >>60dB at 1kHz
- Output impedance: 6 Ohms
Digital To Analogue Convertor (DAC)
- Supported audio file formats: MP3, AAC, WMA, OGG, WMA-L, ALAC, OPUS
- High resolution audio formats: MQA, FLAC, WAV, AIFF
- Native sampling rates: up to 32bit/192kHz
- Bit depths: 16 – 24
BluOS
- Supported operating systems: Plays music from network shares on the following desktop operating systems: Microsoft Windows XP, 2000, Vista, 7, 8 to current Windows Operating Systems and Mac OS X versions
- User interface mobile operating system: BluOS – Free Android and iOS App available online at Google Play and Apple App store
- Supported cloud services (availability will vary depending on location): Spotify, Amazon Music, TIDAL, Deezer, Qobuz, HDTracks, HighResAudio, Murfie, JUKE, Napster, Slacker Radio, KKBox, Bugs
- Free internet radio (availability will vary depending on location): TuneIn Radio, iHeartRadio, Calm Radio, Radio Paradise
- Bluetooth quality: Bluetooth aptX HD wireless built-in
- Bluetooth connectivity: Two-Way (Transmit and Receive)
- Network connectivity:
- Gigabit Ethernet RJ45
- WiFi 5 (802.11 b/g/n)
Connectivity
- Ethernet Port: For wired connection to a home network
- Stereo Analogue RCA Inputs: 2
- Phono Input: Yes, for Moving Magnet (MM) cartridges
- Toslink Optical Digital Audio Inputs: 2
- Coaxial Digital Audio Inputs: 2
- Preamplifier Outputs: Has both RCA and XLR stereo connectivity
- Subwoofer Output: Yes
- USB Type A Input: Connect a USB memory stick or compatible hard drive
- Automation: IR and 12-volt trigger connections for use with external controllers
- Headphone Jack: Full size (1/4") stereo headphone socket on front panel
Other Features
- Dimensions (W x H x D): 435 x 100 x 405mm
- Net Weight: 8.2 kg approx
- Shipping Weight: 10.1 kg
- Manufacturers Warranty: 2 Years
Note: Features & Specifications Subject To Change Without Notice. E&OE