NAD C658

BluOS Streaming DAC

The NAD C 658 BluOS Streaming DAC redefines what a Classic Series component can be, combining a high-performance network streamer, precision DAC, and digital preamplifier in one flexible platform. With BluOS built in, the C 658 provides seamless access to major streaming services and local music libraries through the BluOS Controller app. Its all-digital architecture delivers clean, detailed playback from every source, while Dirac Live calibration—upgradeable to Full Frequency—optimises performance for any room. Built for long-term flexibility, the award-winning C 658 remains a trusted hub for modern two-channel systems.

Key Features:

• BluOS built in for high-resolution streaming and multi-room audio
• High-performance DAC stage for clean, detailed playback
• Includes Dirac Live® Limited Bandwidth licence and calibration microphone for room correction up to 500Hz, with licence upgradeable to Full Frequency
• Fully digital preamplifier architecture with low-noise signal path
• Balanced and single-ended outputs for flexible system integration
• Adjustable digital subwoofer crossover with bass management
• MM phono input plus line-level and digital inputs for legacy sources
• Dual MDC slots for optional future expansion, including HDMI and USB-DSD playback functionality
• Two-way aptX HD Bluetooth for wireless listening
• Gigabit Ethernet, dual-band Wi-Fi, and comprehensive control options
• Supports Dirac Live® Bass Control with optional licence purchase for advanced subwoofer optimisation

Specifications:

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

DAC
Supported audio file formats	MP3, AAC, WMA, OGG, WMA-L, ALAC, OPUS
High resolution audio formats	MQA, FLAC, WAV, AIFF, Supports converted DSD playback via the BluOS desktop app (only)
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	Spotify (also support for Spotify Lossless), Spotift Connect, Amazon Music, TIDAL, Deezer, Qobuz, Qobuz Connect, HDTracks, HighResAudio, Murfie, JUKE, Napster, Slacker Radio, KKBox, Bugs
Free internet radio	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 ac/n)

Dimensions and weight
Dimensions (W x H x D)**	435 x 100 x 405mm
Shipping Weight	10.1kg