NAD C 658 BluOS Streaming Stereo Preamplifier

NAD C 658 BluOS Streaming DAC

The NAD C 658 BluOS Streaming DAC is a modern digital preamplifier and network music streamer built to become the command center of a serious two-channel system. With BluOS onboard, it brings high-resolution streaming, multi-room playback, and app-based control together in one elegant component—while its precision DAC stage and digital-domain volume control keep your signal clean, detailed, and consistent at any listening level. Add Dirac Live Room Calibration (LE included) and the C 658 helps correct room-induced issues for sharper imaging, tighter bass, and a more natural presentation. From turntables and legacy sources to high-res files and today’s streaming platforms, the C 658 is designed to make everything in your system sound more refined.

The NAD C 658 is part of ListenUp's NAD Music Streamer Collection.

What It's Good At:

• Delivering high-resolution streaming with BluOS for single-room or multi-room listening
• Improving clarity and imaging with Dirac Live Room Calibration (LE included)
• Serving as a true system hub with balanced (XLR) and single-ended (RCA) outputs
• Getting seamless bass integration using adjustable digital subwoofer crossover & bass management
• Supporting modern wireless listening with two-way Bluetooth aptX HD (send & receive)
• Staying future-ready via dual MDC slots for optional expansion (including HDMI and USB-DSD functionality)

NAD C 658 Full Specifications:

• Line Input, Pre-Out — THD (20Hz – 20kHz): <0.005% at 2V out
• Line Input, Pre-Out — Signal-to-Noise Ratio: >106dB (IHF; A-weighted, ref. 500mV out, unity gain)
• Line Input, Pre-Out — Channel separation: >80dB (1kHz); >70dB (10kHz)
• Line Input, Pre-Out — Input impedance (R and C): 22 kohms + 100pF
• Line Input, Pre-Out — Maximum input signal: >4.5Vrms (ref. 0.1% THD)
• Line Input, Pre-Out — Output impedance: Source Z + 240 Ohm
• Line Input, Pre-Out — Input sensitivity: 93mV (ref. 500mV out, Volume maximum)
• Line Input, Pre-Out — Frequency response: ±0.3dB (20Hz - 20kHz)
• Line Input, Pre-Out — Maximum voltage output - IHF load: >4.5V (ref. 0.1% THD)
• Line Input, Pre-Out — 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
• Phono Input, Audio Pre-Out — Signal-to-Noise Ratio: >84dB (200 Ohm source; A-weighted, ref. 500mV out); >76dB (MM cartridge source, IHF; A-weighted, ref. 500mV out)
• Phono Input, Audio Pre-Out — Input sensitivity: 1.44mV (ref. 500mV out, Volume maximum)
• Phono Input, Audio Pre-Out — Frequency response: >±0.3dB (20Hz - 20kHz)
• Phono Input, Audio Pre-Out — Maximum input signal at 1kHz: >80mVrms (ref. 0.1% THD)
• Line Input, Headphone Out — THD (20Hz – 20kHz): <0.005% at 1V out
• Line Input, Headphone Out — Signal-to-Noise Ratio: >110dB (32 Ohms loads; A-WTD, ref. 2V out, unity gain)
• Line Input, Headphone Out — Frequency response: ±0.3dB (20Hz - 20kHz)
• Line Input, Headphone Out — Channel separation: >>60dB at 1kHz
• Line Input, Headphone Out — Output impedance: 6 Ohms
• DAC — Supported audio file formats: MP3, AAC, WMA, OGG, WMA-L, ALAC, OPUS
• DAC — High resolution audio formats: MQA, FLAC, WAV, AIFF, Supports converted DSD playback via the BluOS desktop app (only)
• DAC — Native sampling rates: up to 32bit/192kHz
• DAC — 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
• BluOS — User interface mobile operating system: luOS – Free Android and iOS App available online at Google Play and Apple App store
• BluOS — 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
• BluOS — Free internet radio: TuneIn Radio, iHeartRadio, Calm Radio, Radio Paradise
• BluOS — Bluetooth quality: Bluetooth aptX HD wireless built-in
• BluOS — Bluetooth connectivity: Two-Way (Transmit and Receive)
• BluOS — 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)
• Dimensions and Weight — Shipping Weight: 10.1kg (22.3lb)

NAD C 658 Q&A:

What is the NAD C 658 designed to do in an audio system?

It functions as a high-performance digital preamplifier, DAC, and BluOS network streamer—acting as the main hub for sources, streaming, volume control, and outputs to a power amplifier.

Does the C 658 support high-resolution audio playback?

Yes. It supports high-resolution playback up to 32bit/192kHz and works with formats including FLAC, WAV, AIFF, and MQA.

Is room correction included, and can it be upgraded?

Dirac Live LE is included to calibrate the system to your room. It can be upgraded to Dirac Live Full Frequency for more advanced tuning.

Can I stream music throughout the house with the C 658?

Yes. BluOS enables multi-room audio, letting you play and control music across compatible BluOS systems using the BluOS Controller app.

Does it work with a turntable?

Yes. It includes an MM phono input, making it easy to connect a turntable directly.

Can I connect both balanced and standard audio gear?

Yes. It provides balanced and single-ended outputs for flexible integration with a wide range of power amplifiers and systems.

How does Bluetooth work on the C 658?

Bluetooth aptX HD is built in, and it supports two-way Bluetooth—so it can both receive audio from a device and transmit audio to compatible headphones or speakers.

Is the C 658 built to be future-upgradeable?

Yes. Dual MDC slots allow optional expansion, including potential HDMI and USB-DSD playback functionality depending on the installed modules.

NAD C 658 Downloads:

NAD C 658 Manual
NAD C 658 Quick Start Guide
NAD C 658 Data Sheet