C 658 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 Dirac Live LE included, 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 PRODUCT STORY High-Resolution Streaming with BluOS Equipped with BluOS, the C 658 provides seamless access to major streaming services, local music libraries, and high-resolution playback throughout the home. The BluOS Controller app makes it easy to browse and control music in one room or across a multi-room system. Designed for clarity and ease of use, BluOS gives the C 658 intuitive, app-based navigation that brings modern convenience to serious hi-fi listening. Flexible Connectivity for Modern Hi-Fi Designed to integrate effortlessly into high-end audio systems, the C 658 offers a wide range of analogue, digital, balanced, and subwoofer connections. Its digital-domain signal handling, adjustable bass management, and balanced outputs make it a precise, low-noise partner for any power amplifier. Whether pairing with external sources, turntables, or multi-room components, the C 658 unlocks the full performance of your existing system. Precision Digital Processing The C 658 maintains an all-digital signal path to preserve detail and consistency across all inputs. A high-performance DAC stage and digital-domain volume control minimise noise while maintaining transparency at any listening level. This careful design ensures clean, balanced playback from high-resolution streaming to traditional sources. Dirac Live Room Calibration As a Dirac Live component, the C 658 can be calibrated to your listening space using the included licence, with the option to upgrade to Dirac Live Full Frequency for more advanced tuning. Dirac reduces room-induced resonances and improves imaging by correcting both time and frequency response. This optimisation brings greater clarity, depth, and focus, allowing your speakers to perform at their best. SPECIFICATIONS LINE INPUT, PRE-OUT THD (20Hz – 20kHz) 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 Trebleo >±7.0dB at 20kHz; Bass: ±7.0dB at 60Hz; Balance: -10dB PHONO INPUT, AUDIO PRE-OUT THD (20Hz – 20kHz) 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) 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 (17 1/8 x 3 15/16 x 16) Shipping Weight 10.1kg (22.3lb) SOFTWARE & DOWNLOADS DOWNLOADS DATA SHEET 📥 C 658 Data Sheet (PDF) FIRMWARE 📥 BluOS Release Notes 4.14.17 WHITE PAPER 📥 NAD C 658 White Paper (PDF) SOFTWARE 📥 MDC HDM-2 Software Upgrade Procedure for C658 (PDF) 📥 BluOS firmware 4.12.33 Release Notes (PDF) 📥 C 658 Internet Update Guidelines (PDF) MANUALS 📥 Using SR 10 Remote Control with C 658 (PDF) 📥 C 658 Manual - Swedish (PDF) 📥 C 658 Manual - Spanish (PDF) 📥 C 658 Manual - Russian (PDF) 📥 C 658 Manual - Italian (PDF) 📥 C 658 Manual - German (PDF) 📥 C 658 Manual - French (PDF) 📥 C 658 Manual - Dutch (PDF) 📥 C 658 Manual - Chinese (PDF) 📥 C 658 Manual - English (PDF) 📥 C 658 Quick Setup Guide (PDF)
