NAD C 399 BluOS® – Streaming Integrated Amplifier

NAD C 399 BluOS – HybridDigital DAC Streaming Integrated Amplifier

The NAD C 399 BluOS HybridDigital DAC Streaming Integrated Amplifier is the flagship of the Classic Series, combining Masters Series amplification technology with the acclaimed BluOS high-resolution streaming platform and Dirac Live Room Correction — all in a single integrated component. Its HybridDigital nCore amplifier delivers 180 Watts per channel of clean, effortless power, while the installed MDC2 BluOS-D module provides access to hundreds of internet radio stations and over 20 streaming services, whole-home audio integration across up to 64 zones, and room correction up to 500 Hz with a supplied calibrated microphone. Widely recognized by reviewers and honoured with multiple Product of the Year awards, the C 399 BluOS adds HDMI eARC, a precise MM phono stage, and versatile digital and analogue inputs for a fully connected, future-ready music system.

• Class D HybridDigital nCore amplifier topology
• 180 W per channel, continuous (8Ω and 4Ω); 250 W per channel instantaneous
• THD <0.02% (250 mW to 180 W, 8Ω and 4Ω, 20 Hz – 20 kHz)
• 32-bit/384 kHz ESS Sabre 9028 DAC; up to 24-bit/192 kHz digital input support
• BluOS streaming platform via installed MDC2 BluOS-D module; Wi-Fi and Ethernet
• Up to 24-bit/192 kHz via BluOS
• Tidal Connect, Spotify Connect, Qobuz, Roon Ready, Apple AirPlay 2, Amazon Alexa, Google Assistant; MQA decoding and rendering
• Dirac Live Room Correction (Limited Bandwidth, 20 Hz – 500 Hz); full-bandwidth upgrade available; calibrated microphone included
• Moving Magnet (MM) phono stage with infrasonic filtering
• Two-way Qualcomm aptX HD Bluetooth (via MDC2 BluOS-D)
• Dedicated headphone amplifier, 1/4" (6.3 mm) output
• Made in China
• 2 Year Warranty

Highlights & Key Technologies

HybridDigital nCore Amplification
The C 399 BluOS employs NAD's HybridDigital nCore amplifier platform, trickled down from the Masters Series, to deliver 180 Watts per channel of continuous power into 8 and 4 ohms, and 250 Watts per channel instantaneous power. The nCore design is renowned for its wide bandwidth, flat frequency response, clean clipping behaviour with instant recovery, high current capability, and stability into demanding low-impedance speaker loads. Noise and distortion are vanishingly low under all operating conditions, with the minute levels of harmonic distortion dominated by sonically benign second and third harmonics. The result is detailed, dynamic playback that preserves the energy and expression of the music, even at very high listening levels.

ESS Sabre DAC & Digital Architecture
The C 399 BluOS's digital section is built around the 32-bit/384 kHz ESS Sabre 9028 high-resolution DAC — the same chip used in NAD's acclaimed M10 and M33 Masters Series amplifiers — noted for its near-zero clock jitter, ultra-low noise and distortion, and wide dynamic range. A refined digital architecture ensures low noise, accurate imaging, and wide dynamic range across all sources, revealing greater texture, definition, and openness in recordings. Digital inputs support audio up to 24-bit/192 kHz.

BluOS Streaming via MDC2 BluOS-D
The C 399 BluOS includes the MDC2 BluOS-D module, which adds the BluOS high-resolution multi-room streaming platform via Wi-Fi and Ethernet. The BluOS Controller app — available for iOS, macOS, Android, and Windows — provides access to hundreds of internet radio stations and over 20 streaming services, including several that deliver lossless and high-resolution audio up to 24-bit/192 kHz. Supported services and integrations include Tidal Connect, Spotify Connect, Qobuz, Roon Ready, Apple AirPlay 2 with Siri voice control, Amazon Alexa voice control, Google Assistant voice control, and MQA decoding and rendering. The MDC2 BluOS-D also incorporates two-way Qualcomm aptX HD Bluetooth. A USB port allows playback from a connected USB drive. Thanks to MDC2's bidirectional architecture, audio from any source connected to the C 399 can be shared with up to 63 additional BluOS-enabled components on the same network, for whole-home audio in up to 64 zones. Playback can also be controlled from smart home systems including Crestron, Control4, Lutron, RTI, and others.

Dirac Live Room Correction
The MDC2 BluOS-D includes a license for Dirac Live Room Correction (Limited Bandwidth, 20 Hz – 500 Hz), with the option for advanced users to upgrade to the Dirac Live Full Frequency version. Room acoustics can significantly affect sound quality, causing uneven bass and blurred imaging. Dirac Live analyses the listening space using the supplied calibrated microphone and applies correction filters to the MDC2 BluOS-D module, improving bass clarity, imaging, and tonal accuracy. The module can store up to five Dirac profiles for different listening positions or room conditions. Thanks to MDC2's two-way architecture, Dirac Live room correction applies to all sources connected to the C 399, not only streamed content.

Analogue Inputs & MM Phono Stage
Two pairs of RCA line-level inputs feature low-noise buffer amplifiers to prevent sonic degradation. The dedicated MM phono stage delivers ultra-precise RIAA equalization, extremely low noise, and high overload margins. An innovative circuit suppresses the infrasonic noise present on all LPs without compromising bass response. Analog bypass mode keeps analog signals in the analog domain without analog-to-digital conversion, with tone control functions remaining operative.

Digital Inputs & HDMI eARC
The C 399 BluOS provides two optical and two coaxial digital inputs. The HDMI eARC port allows audio from a connected TV to be played through the C 399 — including control of amplifier output via the TV's remote using HDMI CEC. eARC is the default mode and falls back to ARC if no eARC connection is established. Only audio output from a connected TV is supported by the HDMI eARC port; there is no video output.

Outputs, Headphone Amplifier & MDC2 Platform
The C 399 BluOS provides two sets of speaker terminals (Speaker A and Speaker B, operating in parallel), dual subwoofer outputs, and a preamplifier output. The dedicated headphone amplifier features a low output impedance of 2.2 ohms and high output voltage capability, enabling the C 399 BluOS to drive demanding high-impedance headphones; inserting a headphone jack automatically switches off the speaker, pre-out, and subwoofer outputs. The second MDC2 slot remains available for future upgrade modules. Tone controls (bass, treble ±7 dB, and balance) and a volume control with variable or fixed (cinema bypass) mode are provided.

Control & Integration
The C 399 BluOS includes comprehensive control integration support: RS-232 serial port, 12V trigger input and output, and IR input and output. NAD is a certified partner of AMX and Crestron, with full compatibility confirmed for Control4, Crestron, RTI, URC, Push, Lutron, iPort, and Elan. The included SR 10 remote control handles key functions and can be programmed to control up to four devices.

Details & Specifications

AMPLIFIER – LINE IN, SPEAKER OUT (ANALOG BYPASS ON)
Continuous output power into 8Ω and 4Ω: 180 W (ref. 20 Hz–20 kHz at rated THD, both channels driven)
THD (20 Hz – 20 kHz): <0.02% (250 mW to 180 W, 8Ω and 4Ω)
Signal-to-Noise Ratio: >95 dB (A-weighted, 500 mV input, ref. 1 W out in 8Ω)
Clipping power: >210 W (at 1 kHz, 0.1% THD)
IHF dynamic power: 8Ω: 217 W | 4Ω: 400 W | 2Ω: 505 W (per manual); 506.4 W (per data sheet)
Peak output current: >26 A (in 1Ω, 1 ms)
Damping factor: >150 (ref. 8Ω, 20 Hz to 6.5 kHz)
Frequency response: ±0.3 dB (20 Hz – 20 kHz)
Channel separation: >90 dB (1 kHz); >75 dB (10 kHz)
Input sensitivity (for 180 W in 8Ω): Line In: 201 mV | Digital In: 10.25% FS

PREAMPLIFIER – LINE INPUT, PRE-OUT (ANALOG BYPASS ON)
THD (20 Hz – 20 kHz): <0.002% at 2 V out
Signal-to-Noise Ratio: >106 dB (IHF; A-weighted, ref. 500 mV out, unity gain)
Channel separation: >100 dB (1 kHz); >90 dB (10 kHz)
Input impedance (R and C): 56 kΩ + 100 pF
Maximum input signal: >4.6 Vrms (ref. 0.1% THD)
Output impedance: Source Z + 320 Ω
Input sensitivity: 65 mV (ref. 500 mV out, Volume maximum)
Frequency response: ±0.3 dB (20 Hz – 20 kHz)
Maximum voltage output – IHF load: >5 V (ref. 0.1% THD)

PHONO – PHONO INPUT, PRE-OUT (ANALOG BYPASS ON)
Cartridge compatibility: Moving Magnet (MM) only
THD (20 Hz – 20 kHz): <0.01% at 2 V out
Signal-to-Noise Ratio: >84 dB (200 Ω source; A-weighted, ref. 500 mV out)
Input impedance (R and C): 46 kΩ / 100 pF
Input sensitivity: 1.08 mV (ref. 500 mV out, Volume maximum)
Frequency response*: ±0.3 dB (20 Hz – 20 kHz)
Maximum input signal at 1 kHz: >80 mVrms (ref. 0.1% THD)
*RIAA response is consistent with a pre-emphasis rolled off at 50 kHz by a second-order filter, as used in Neumann cutting lathes.

HEADPHONE – LINE INPUT, HEADPHONE OUT (ANALOG BYPASS ON)
THD (20 Hz – 20 kHz): <0.005% at 1 V out
Signal-to-Noise Ratio: >107 dB (32 Ω loads; A-weighted, ref. 1 V out, unity gain (per manual); ref. 2 V out, unity gain (per data sheet))
Frequency response: ±0.3 dB (20 Hz – 20 kHz)
Channel separation: >62 dB (1 kHz)
Output impedance: 2.2 Ω
Output connector: 1/4" (6.3 mm) stereo jack

GENERAL SPECIFICATIONS
Digital input bit rate / sample rate support: up to 24-bit/192 kHz
BluOS maximum streaming resolution: up to 24-bit/192 kHz
Bluetooth frequency band: 2.402 GHz – 2.480 GHz (MDC2 BluOS-D)
Bluetooth codec: Qualcomm aptX HD (two-way, via MDC2 BluOS-D)
Network standby power: 0.6 W
Auto standby power: <0.5 W

INPUTS
Optical digital: 2 (TOSLINK)
Coaxial digital: 2 (RCA)
HDMI: 1 (eARC/ARC)
Analogue line: 2 (RCA pairs)
Phono: 1 (MM, RCA pair with ground terminal)
USB (MDC2 BluOS-D): 1 (for local USB drive playback)
Bluetooth: Yes (two-way, Qualcomm aptX HD, via MDC2 BluOS-D)
Wi-Fi / Ethernet: Yes (via MDC2 BluOS-D)

OUTPUTS
Speaker terminals: 2 sets (A and B, operating in parallel)
Subwoofer: 2 (RCA)
Preamplifier: 1 (RCA pair)
Headphone: 1 (1/4" / 6.3 mm stereo jack)

STREAMING & ROOM CORRECTION (MDC2 BluOS-D)
Streaming platform: BluOS
Supported services: Tidal Connect, Spotify Connect, Qobuz, Roon Ready, Apple AirPlay 2, Amazon Music HD, Deezer, and others
Voice control: Apple Siri (via AirPlay 2), Amazon Alexa, Google Assistant
MQA: Decoding and rendering supported
Multi-room zones: Up to 64 (1 host + up to 63 additional BluOS-enabled components)
Room correction: Dirac Live Limited Bandwidth (20 Hz – 500 Hz); full-bandwidth upgrade available
Dirac profiles stored: Up to 5
Calibrated microphone: Included

CONTROL & CONNECTIVITY
RS-232: Yes (serial port)
IR In / IR Out: Yes
12V Trigger In / Out: Yes
MDC2 expansion slots: 2 (1 occupied by MDC2 BluOS-D; 1 remaining)
Home automation compatibility: Control4, Crestron, RTI, URC, Push, Lutron, iPort, Elan

DIMENSIONS & WEIGHT
Gross dimensions (W × H × D): 435 × 120 × 390 mm (17 1/8 × 4 3/4 × 15 3/8 inches)*
Net weight: 10.1 kg (22.3 lbs) (per manual); 11.2 kg (24.7 lbs) (per data sheet and product page)
Shipping weight: 12.6 kg (27.8 lbs) (per manual); 13.6 kg (30 lbs) (per data sheet and product page)
*Gross dimensions include feet, volume knob, and extended rear panel terminals including installed antennas.

INCLUDED ACCESSORIES
SR 10 remote control with 2 AA batteries
Two detachable mains power cords
Bluetooth antennas
MDC2 BluOS-D module (installed)
Calibrated microphone assembly with USB MIC Sound Adaptor (for Dirac Live setup)

COUNTRY OF MANUFACTURE & WARRANTY
Country of Manufacture: China
Warranty: 2 Years