Audio T Verdict
The Naim NSS 333 is a dedicated 300 Series network music source with a high-resolution streaming platform, built-in DAC, four S/PDIF inputs, USB playback and a choice of DIN, balanced XLR, RCA or BNC digital output. It is intended to feed a separate preamplifier rather than control loudspeaker volume itself.
The supplied 5-pin DIN interconnect provides the preferred connection to the matching NAC 332. Fixed-level XLR and RCA outputs extend compatibility to other suitable preamplifiers, while the BNC digital output allows use with an external DAC. Output selection matters: XLR and RCA must be enabled in the app, and enabling the digital output disables the analogue outputs.
The NSS 333 has no analogue input, volume control, phono stage, headphone output or loudspeaker amplifier. Its internal linear power supply makes it complete as supplied, with the NPX 300 available as the supported optional two-cable power upgrade.
Naim NSS 333 High-Resolution Network Streamer
The NSS 333 is Naim's New Classic 300 Series network streamer and digital source. It combines the NP800 streaming platform with a precision digital-processing stage, PCM1791A conversion and discrete Class A analogue output circuitry.
It is designed to connect to a preamplifier such as the
Naim NAC 332
,
followed by a power amplifier and passive loudspeakers. It can also feed another compatible preamplifier or integrated amplifier through its fixed-level DIN, XLR or RCA outputs.
What It Includes
- Network streamer and high-resolution DAC
- Spotify Connect, TIDAL, Qobuz and internet radio
- AirPlay 2, Google Cast and Bluetooth
- UPnP, Roon Ready and USB storage playback
- Four S/PDIF digital inputs
- DIN, balanced XLR and RCA analogue outputs
- BNC coaxial digital output
- Focal and Naim App, front-panel and remote control
What It Does Not Include
- No volume control or preamplifier
- No analogue audio input
- No phono stage or headphone output
- No power amplifier or loudspeaker terminals
- No HDMI ARC or eARC connection
- No USB computer-audio input
- No internal hard drive or CD-ripping mechanism
- No NPX 300 in the standard package
A Dedicated Source, Not a Streaming Preamplifier
The NSS 333 outputs a fixed line-level or digital signal. A preamplifier must select the source and control the listening volume before the signal reaches a power amplifier or active loudspeakers.
The illuminated ring on the supplied remote may control a paired NAC 332 through Naim's Zigbee system, but this does not turn the NSS 333 into a variable-output preamplifier. Do not connect its fixed analogue output directly to a conventional power amplifier.
Choose NSC 222 When Volume Control Is Required
The
Naim NSC 222
combines streaming with analogue inputs, volume control, an MM phono stage and headphone output. The NSS 333 is the more specialised source for a separate-preamp system.
Current Streaming Platform
The NP800 platform provides access to streamed services, internet radio, local network libraries and compatible phone, tablet or computer playback. The Focal and Naim App handles browsing, input and output setup, presets, multiroom grouping and wireless product updates on iOS and Android.
Current platform support includes Spotify Connect, TIDAL, TIDAL Connect, Qobuz, Qobuz Connect, Apple AirPlay 2, Google Cast, aptX Adaptive Bluetooth, internet radio, UPnP network playback, Roon Ready operation and USB storage playback. Service accounts, subscriptions and compatible control devices may be required, and third-party availability can change.
Apple Music Playback
Apple Music can be sent from a compatible Apple device using AirPlay 2. This is different from a native Apple Music browser inside the Focal and Naim App.
Ethernet, Wi-Fi and Local Network Music
A 10/100 Ethernet socket provides the preferred network connection where cabling is practical. Dual Wi-Fi antennas are integrated into the heatsink and support 802.11a/b/g/n/ac networking without external aerials.
UPnP playback allows the NSS 333 to browse music from a compatible server or NAS. Roon Ready certification allows it to operate as a network endpoint within a separately licensed Roon system.
USB Playback, Storage and Server Function
USB Type A sockets are fitted at the front and rear for compatible storage devices. Naim's guide lists support for USB sticks up to 128GB and portable hard drives up to 1TB, with libraries of up to 20,000 tracks. The contents of attached storage can also be served to a compatible network player.
The ports provide up to 1.6A for charging, subject to the device and operating state. They are host ports for storage and charging, not USB Type B inputs, and the NSS 333 cannot operate as a directly connected USB DAC for a computer.
There is no internal hard drive or optical disc mechanism. The NSS 333 does not rip CDs by itself, and music remains on the connected storage device or network server.
NP800 Streaming and DSP Architecture
The NP800 streaming card transfers digital audio using low-voltage differential signalling to reduce noise. Separate master clocks serve the 44.1kHz and 48kHz sample-rate families, and the player operates as clock master for streamed sources.
A 40-bit floating-point SHARC processor buffers S/PDIF inputs and applies Naim's integer-oversampling filter at 705.6kHz or 768kHz. The DSP is used for digital filtering and timing management; the NSS 333 does not contain a user-configurable loudspeaker crossover.
PCM1791A DAC and Discrete Analogue Stage
Digital-to-analogue conversion is performed by a PCM1791A DAC operating with Naim's external digital filter. The following analogue stage uses discrete transistor Class A amplifiers and filters, with selected polystyrene capacitors in the post-DAC filter network.
Network and USB playback supports WAV up to 32-bit/384kHz, FLAC, AIFF and ALAC up to 24-bit/384kHz, and DSD64 or DSD128. The 384Hz figure reproduced in some specification tables is a typographical error; the intended maximum for FLAC, AIFF and ALAC is 384kHz.
Four Digital Inputs
Two optical TOSLink inputs accept PCM audio up to 24-bit/96kHz. A coaxial RCA input and a coaxial BNC input support up to 24-bit/192kHz and DoP64.
Naim recommends the BNC input where the source offers a suitable 75O coaxial output. Input names can be changed and unused inputs disabled in the app.
The optical inputs can accept two-channel PCM from a compatible television, but the NSS 333 has no HDMI ARC connection and does not decode Dolby or DTS multichannel audio. The television must be configured to output a supported stereo PCM signal.
DIN, XLR and RCA Analogue Outputs
Three fixed-level analogue output formats are provided: one 5-pin DIN socket, one balanced XLR pair and one stereo RCA pair. Naim specifies 2.1Vrms from the XLR and RCA connections.
The DIN output is Naim's preferred connection and the package includes a 5-pin 180-degree DIN interconnect. Its banded end connects to the NSS 333 and the unbanded end to the preamplifier.
XLR and RCA outputs allow connection to suitably equipped Naim or third-party preamplifiers. They must be enabled in the Focal and Naim App, and unused outputs should be disabled. The word “balanced” describes the XLR connection; it does not mean the output level is variable.
Compatibility Must Be Checked by Connection
The NSS 333 is not literally compatible with every Naim product. The receiving component must provide a suitable line-level input, and some older Naim products may require a different cable. Confirm the input socket, pin arrangement and required lead before ordering.
BNC Digital Output for an External DAC
A coaxial BNC digital output supports PCM audio up to 24-bit/192kHz. It allows the streaming platform and digital-source switching to feed a compatible external DAC.
Digital and Analogue Outputs Are Mutually Exclusive
The BNC digital output must be enabled in the app. When it is active, the NSS 333's DIN, XLR and RCA analogue outputs are disabled. Re-enable the required analogue output before returning to the internal DAC.
Display, Front Controls and Zigbee Remote
A 5.5-inch colour display shows album artwork and playback information. Front-panel buttons provide quick access to standby, play or pause, inputs and favourites, while the Naim logo brightness can be adjusted in the app.
The supplied bidirectional Zigbee RF remote does not need a direct line of sight. It controls the streamer and can communicate with a paired NAC 332, allowing the preamplifier's volume and system operation to be managed from the same handset.
Multiroom and System Automation
Naim multiroom operation can group compatible Naim streaming products through the Focal and Naim App. Party Mode can synchronise up to six Naim streamers, subject to network and product compatibility. AirPlay 2, Google Cast and Roon provide additional grouping options within their respective systems.
In a matching 300 Series system, the NSS 333 and NAC 332 coordinate through Zigbee. Optical automation cables then connect the NAC 332 to compatible NAP 350 power amplifiers for synchronised standby and logo illumination. The required power-amplifier automation cables are supplied with the NAP 350 units.
Internal Power Supply and NPX 300 Upgrade
The NSS 333 is complete with its own internal linear power supply, using a custom four-winding toroidal transformer and soft-start circuitry. Control and audio sections are galvanically isolated, while a separate low-consumption arrangement supports standby below 0.5W.
The optional
Naim NPX 300
powers the analogue and digital sections through separate Type 3 and Type 4 Burndy connections. Both link plugs remain fitted when the NSS 333 uses its internal supply. For NPX 300 operation, the NSS 333 mains lead and both link plugs are removed, and only the NPX 300 connects to mains power.
Correct Power-Supply Compatibility
The direct external power-supply option for the NSS 333 is the NPX 300. The ND 555 is a separate reference network player, not a power supply or upgrade module for the NSS 333. Do not substitute an NPX TT, XPS DR, 555 PS DR or unidentified Burndy cable.
Standby Modes
Standard standby consumption is below 0.5W. Network standby remains below 2W and allows the NSS 333 to wake through the app when connected to Ethernet or Wi-Fi.
A higher-power network standby state keeps the unit fully powered with its display and logo off when it must power a USB device or act as a server. Normal operating consumption is approximately 25W. Auto standby is enabled by default and activates after no more than 20 minutes of inactivity.
Installation and System Earthing
Support the 11kg aluminium chassis on a stable, level and ventilated equipment rack. Do not stack Naim components directly, and keep power amplifiers and large power supplies away from the streamer and preamplifier where practical.
Use Ethernet where practical. If Wi-Fi is required, avoid enclosing the heatsink antennas in metal furniture or placing the unit where the network signal is heavily screened.
The rear signal-ground switch should normally remain at Default when the NSS 333 is the primary source providing the system's signal-earth reference. Use Floating only when another connected source already provides the required earth connection and hum diagnosis supports the change.
Key Features
- Dedicated 300 Series network streamer and digital source
- NP800 streaming platform with high-resolution playback
- Spotify Connect, TIDAL, TIDAL Connect, Qobuz and Qobuz Connect
- Apple AirPlay 2, Google Cast and aptX Adaptive Bluetooth
- UPnP, internet radio, USB storage and Roon Ready operation
- WAV playback up to 32-bit/384kHz and DSD128 support
- Two optical, one coaxial RCA and one coaxial BNC digital input
- DIN, balanced XLR and RCA fixed analogue outputs
- BNC digital output up to 24-bit/192kHz
- PCM1791A DAC with discrete Class A analogue circuitry
- 40-bit SHARC processing and integer-oversampling filter
- 5.5-inch colour display and bidirectional Zigbee remote
- Ethernet, dual-antenna Wi-Fi and Naim multiroom support
- Internal linear power supply with optional NPX 300 upgrade
- Power-Line Lite and 5-pin DIN interconnect supplied
Frequently Asked Questions
Is the NSS 333 a preamplifier?
No. Its analogue outputs are fixed level. Connect it to a preamplifier or a suitable line input on an integrated amplifier before the power-amplifier stage.
Can it connect directly to a power amplifier?
Not safely in a conventional system because the NSS 333 has no listening-volume control. Use a preamplifier such as the NAC 332 between the streamer and power amplifier.
What is the difference between NSS 333 and NSC 222?
NSS 333 is a dedicated 300 Series streaming source. NSC 222 adds preamplifier volume control, analogue inputs, an MM phono stage and a headphone amplifier, allowing it to connect directly to a power amplifier.
Which analogue output should I use?
Naim recommends the DIN output and supplies a suitable 5-pin DIN lead for the NAC 332. Balanced XLR or RCA can be used with another compatible preamplifier and must be enabled in the app.
Is the DIN cable included?
Yes. A 5-pin 180-degree DIN interconnect is supplied. The banded end connects to the NSS 333.
Does it have a digital output?
Yes. The BNC coaxial output supports PCM up to 24-bit/192kHz for a compatible external DAC. Enabling it disables the analogue outputs.
Can the analogue and digital outputs operate together?
No. Naim states that enabling the digital output disables the analogue outputs. Select the required output arrangement in the Focal and Naim App.
Does the NSS 333 have an analogue input?
No. Despite an analogue-input icon appearing on one published connection list, the hardware and technical specifications provide digital inputs only.
Can I connect a television?
A compatible television can use an optical input when set to two-channel PCM. There is no HDMI ARC and the NSS 333 does not decode Dolby or DTS multichannel formats.
Can I connect a computer by USB?
Not as a direct USB DAC. The USB Type A ports accept compatible storage and provide charging. A computer can reach the streamer through the network, Roon, AirPlay 2, Google Cast or a suitable S/PDIF interface.
Can it store and serve music?
It can play and serve music from attached USB storage. Naim lists up to 20,000 tracks, portable drives up to 1TB and USB sticks up to 128GB. It has no internal drive and does not rip CDs itself.
Is the NSS 333 Roon Ready?
Yes. It can operate as a Roon Ready endpoint when used with a separate licensed Roon server and suitable network.
Does it play Apple Music?
Apple Music can be sent from a compatible Apple device through AirPlay 2. It should not be described as a native Apple Music service within the Focal and Naim App.
Is the NPX 300 required?
No. The NSS 333 has its own internal power supply and works as supplied. NPX 300 is an optional external power-supply upgrade.
Can I use a 555 PS DR or XPS DR?
No. Naim specifies the NPX 300 as the direct external power-supply option for NSS 333. Use the Type 3 and Type 4 cables supplied with the NPX 300 exactly as described in the manuals.
What are the supplied link plugs for?
They complete the internal power-supply connections when no NPX 300 is attached. Both must be fitted for standalone operation and removed only during the correct NPX 300 installation process.
Why Buy From Audio T?
- NSS 333 and 300 Series demonstrations by arrangement
- NAC 332 and legacy preamplifier compatibility checks
- DIN, XLR, RCA and BNC cable advice
- Network, app and streaming-service setup support
- NAS, UPnP, Roon and USB library guidance
- Digital-output and external-DAC configuration
- NPX 300 demonstrations and installation guidance
- Equipment-rack, cable-dressing and system-earthing advice
- Part-exchange options on suitable equipment
- Ongoing Naim system and servicing support
Contact your local Audio T store
to arrange a demonstration and confirm the preamplifier, output cable, network, storage and optional power-supply requirements for your system.
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