NAD CI-720 v2

The NAD CI 720 V2 is a network stereo amplifier that combines NAD’s HybridDigital amplification technology with the BluOS streaming platform. It delivers a continuous power output of 60 watts per channel, with a maximum dynamic power of 165 watts, and boasts a total harmonic distortion of less than 0.005%. Designed for custom installations, its blade format allows up to six units to be integrated into a 3U rack, enabling management of up to 64 distinct audio zones in multiroom systems.

Blade Architecture and Optimized Thermal Design

The blade format of the CI 720 V2 represents a radically different approach from traditional rack amplifiers. With its compact dimensions of 70 × 120 × 350 mm and a weight of only 1.6 kg, each module occupies one-sixth of the standard rack space when mounted in the RM 720 accessory. This vertical design allows six complete stereo zones to be installed in a 3U space, cutting the footprint in half compared to conventional amplifiers.

Thermal management is a major challenge in dense rack installations. NAD has integrated a thermostatic cooling system with a front air intake that draws in cool air and directs it to the rear of the unit through strategically positioned vents. This forced airflow ensures optimal operating temperature even in the most demanding rack environments, where accumulated heat from multiple devices can compromise long-term reliability. The fan only activates when needed, thus preserving silent operation during low-volume listening.

The RM 720 rack-mount accessory transforms the management of multiple CI 720 V2 units into an organized, professional system. Beyond simple mechanical support, the RM 720 integrates power management and Ethernet switching, greatly simplifying installation and cabling. Cover plates are provided to maintain a clean front panel when fewer than six amplifiers are installed, preserving the professional look of the setup.

HybridDigital Amplification Technology and Hypex UcD Modules

The HybridDigital amplification of the CI 720 V2 is based on custom Hypex UcD output modules, a technology originally developed by engineer Bruno Putzeys and refined by NAD for its specific applications. This class D approach uses a variable modulation frequency to reproduce the natural qualities of music while reducing distortion under all operating conditions.

UcD modules stand out for their perfectly flat frequency response regardless of load impedance, distortion behavior that is nearly independent of frequency, and exceptionally low radiated and conducted electromagnetic emissions. This last feature is crucial in rack installations where the proximity of multiple electronic devices can generate mutual interference. The self-oscillating phase-controlled loop takes its feedback directly from the speaker output, ensuring instant correction of any signal deviation.

The high-efficiency switching power supply maintains near-perfect voltage regulation across a wide range of conditions, providing a quiet and stable foundation for the amplification stages. This universal power supply accepts any mains voltage from 100 to 240 volts, allowing worldwide use without modification. The high energy efficiency of this topology generates less residual heat, contributing to long-term reliability in confined environments.

The load-invariant nature of HybridDigital amplification allows the CI 720 V2 to handle 4-ohm loads as easily as 8-ohm loads, with no change in its sonic characteristics. This stability ensures consistent performance with a wide variety of speakers, from high-efficiency models to more current-demanding designs. The -110 dBA signal-to-noise ratio ensures a completely silent background, preserving micro-details even in the most delicate passages.

BluOS Integration and High-Resolution Streaming Capabilities

The BluOS platform transforms the CI 720 V2 into much more than just an amplifier. This audio operating system developed by Bluesound enables wireless streaming of high-resolution music up to 24-bit/192 kHz over the home network, with no latency or loss of sound quality. Unlike compressed streaming solutions, BluOS maintains the integrity of the original audio signal, preserving every nuance of the recording.

The network architecture uses the standard multicast protocol, eliminating the need for meshing between players and allowing expansion up to 64 independent zones. Each zone can stream its own music or be grouped with others for perfectly synchronized playback. The system’s flexibility allows for fixed groups for permanent setups, such as stereo pairs or home theater systems, or temporary groups for special events.

The BluOS Controller app, available for iOS, Android, Windows, and macOS, centralizes control of the entire system. The intuitive interface features a customizable home screen with the most-used functions and the latest updates. The smart search function remembers recent queries and suggests relevant content based on listening habits. Local music libraries shared on the network are automatically indexed, allowing navigation by artist, album, genre, or custom playlist.

Native support for over twenty streaming services eliminates the need for third-party apps. Supported services include Spotify, TIDAL, Qobuz, Deezer, Amazon Music, Napster, and many more, each accessible directly from the BluOS interface. Internet radio stations from around the world are available via TuneIn Radio and iHeartRadio, offering instant access to thousands of live streams. Support for the MQA (Master Quality Authenticated) format enables playback of studio master files with exceptional fidelity, reproducing exactly what the artist approved in the studio.

Redundancy and Reliability in Professional Installations

The modular architecture of the CI 720 V2 offers a crucial advantage in terms of system redundancy. Each unit operates completely independently, meaning that a potential failure of one module does not affect any other zone. This isolation ensures that music continues throughout the rest of the property even in the event of a localized issue, a critical aspect for commercial installations where service continuity is paramount.

Each CI 720 V2 has its own dedicated analog and digital inputs, allowing connection of local sources specific to each zone. This flexibility is especially useful in commercial environments where different zones may require distinct audio sources, such as background music in a restaurant and announcements in conference areas. Connectivity can be further expanded via the Bluesound HUB to add even more input options.

The standby power consumption of just 6 watts in network mode demonstrates NAD’s commitment to energy efficiency. In a six-zone setup, this represents substantial savings compared to traditional class A/B amplifiers, which is especially important in commercial installations operating 24/7. The universal power supply also simplifies inventory management for international integrators, as a single model covers all global markets.

Frequently Asked Questions

Can the CI 720 V2 operate without an Internet connection?
Yes, the amplifier works perfectly with local inputs (USB, optical, analog) without an Internet connection. However, access to streaming services, Internet radio, and software updates requires an active Internet connection. Ethernet connectivity remains mandatory for network integration, even for local use.

What is the difference between the CI 720 V2 and the original CI 720?
The V2 version brings several significant improvements, including better thermal management with the optimized thermostatic cooling system, native AirPlay 2 compatibility, and enhancements to the BluOS interface. Amplification specifications remain identical, but reliability and system integration have been considerably improved.

Can 4-ohm speakers be used with the CI 720 V2?
Absolutely. HybridDigital technology is load-invariant, handling 4-ohm impedances as easily as 8 ohms. The amplifier maintains its performance characteristics and stability regardless of the connected speakers’ impedance, with no risk of overheating or distortion.

How does the MQA feature improve sound quality?
MQA is an end-to-end technology that captures and delivers master-quality audio. The built-in MQA decoder and renderer in the CI 720 V2 fully unfold MQA files, reproducing exactly the sound approved by the artist in the studio. The MQA logo in the BluOS app confirms correct decoding of the stream or file.

Does the CI 720 V2 require complex programming for home automation integration?
No, official drivers for major control systems are provided and regularly updated. Integration is generally done via each system’s standard programming interface. For end users, the BluOS Controller app offers all necessary features without programming.

What is the maximum range of the BluOS multiroom system?
BluOS can manage up to 64 zones on the same network, far beyond the needs of most installations. The range depends on the network infrastructure rather than the BluOS system itself. For best performance with more than 16 zones, an Ethernet connection is recommended for each player.

Technical Specifications

Amplification and System Compatibility

• HybridDigital Amplification
• Compatible systems: Control4, RTI, Crestron, URC, Roon

Services and Protocols

• Wireless protocols: AirPlay 2, DLNA
• Streaming services: WiMP, Slacker Radio, Qobuz, HighResAudio, JUKE, Deezer, Murfie, HDTracks, Spotify, TIDAL, Napster, Microsoft Groove (with OneDrive), Classics Online, KKBox
• Internet radios: TuneIn Radio, iHeartRadio, Calm Radio, Radio Paradise

Audio Formats

• Supported formats: MP3, AAC, WMA, OGG Vorbis, WMA-L, FLAC, ALAC, WAV, AIFF, MQA, HRA
• Maximum resolution: 24-bit / 192 kHz
• Sampling rate: 32 - 192 kHz

Audio Performance

• Power:
  • Continuous: 2 × 60 W
  • Peak: 2 × 165 W
• Total harmonic distortion: ≤ 0.005%
• Signal-to-noise ratio: -110 dBA

Connectivity

• 1 USB Type-A port (USB playback, FAT32 format)
• 1 RCA input
• 1 optical input
• 1 3.5 mm mini-jack input
• 1 RJ45 Ethernet port
• Phoenix terminals for speakers

Physical Characteristics

• Power supply: 100-240 V ~ 50/60 Hz
• Standby power consumption: 6 W (Network standby mode)
• Dimensions (W × H × D): 70 × 120 × 350 mm
• Weight: 1.6 kg