Matrix Audio ND-1

With the N series, Matrix Audio has split its desktop Hi-Fi chain into separate elements, each dedicated to a single function. The NT-1 transport, released in March 2025, handled the source. What it lacked was a conversion partner. The ND-1 fills that role: a pure digital-to-analog converter, with no built-in streaming, no headphone amplification, focused solely on the task of turning a digital stream into an analog signal.

The AKM chip in a “1+2” configuration

The ND-1 is built around AKM’s flagship chip duo: an AK4191EQ delta-sigma modulator paired with two AK4499EX converters, one per channel. Matrix Audio refers to this as a “1+2” topology: the AK4191EQ handles digital processing and reclocking, then distributes the signal to each AK4499EX operating in dedicated mono mode. This physical separation of the left and right channels improves crosstalk (specified at -145 dB on the XLR output in Op-Amp mode) and phase coherence.

The MS-1, the brand’s flagship, also uses these AKM chips, but in a “2+2” configuration with two AK4191 and two AK4499. The ND-1 is not a miniaturized MS-1: it is a different interpretation of the same chipset, in a more compact format and at a distinct price positioning.

Two sound signatures in a single chassis

This is probably the ND-1’s most distinctive feature. The output stage offers two modes, switchable on the fly:

In transformer mode, the signal passes through Lundahl transformers, known for their warm coloration and “analog” texture. Harmonic distortion rises slightly (below 0.02% versus 0.0002% in Op-Amp mode), and bandwidth narrows a bit (-3 dB at 85 kHz instead of 90 kHz), but the signal-to-noise ratio remains identical (above 127 dB in XLR). In Op-Amp mode, the sound gains speed, definition, and transient precision. Two sonic personalities coexist, without the need to change cabling or components.

This choice is not a gimmick. Lundahl transformers are costly components found in high-end studio converters and preamplifiers. Their presence here, alongside a conventional Op-Amp output, provides real flexibility depending on the type of music or the downstream amplification.

Clocking and jitter management

The ND-1 features a femtosecond clock with low phase noise, coupled with a DPLL circuit that Matrix Audio says is inherited from the MS-1. A 10 MHz external clock input (50 Ω, sinewave or squarewave signal) is available on the rear to connect the SC-1, the brand’s reference clock.

The converter also includes an asynchronous upsampling engine and PCM to DSD conversion, with several adjustable configurations. The idea is to reclock the incoming signal to isolate residual jitter before conversion. Conversion settings (PCM or DSD mode, upsampling rate) are accessible from the device.

Six digital inputs, all isolated

The rear panel groups together six inputs: coaxial S/PDIF, optical Toslink, AES/EBU, IIS-LVDS (via HDMI connector), USB Type B, and USB Type C. All benefit from electrical isolation, a design choice intended to eliminate ground loops and interference between source and converter.

The IIS-LVDS connection, designed primarily to connect the NT-1 transport, carries the I2S signal and supports PCM streams up to 32-bit / 768 kHz and native DSD up to DSD1024 (49.15 MHz). The USB inputs go up to PCM 768 kHz and native DSD512. The S/PDIF and AES/EBU inputs remain limited to PCM 192 kHz and DSD64 via DoP, in accordance with the protocol’s constraints.

The two USB ports (Type B and Type C) allow a computer and a smartphone or tablet to be connected simultaneously, without having to unplug anything.

Analog outputs and volume control

The ND-1 offers one pair of balanced XLR outputs (4.5 Vrms) and one pair of unbalanced RCA outputs (2.25 Vrms). Two alternative output levels are available: 4 Vrms / 4.5 Vrms in XLR, and 2 Vrms / 2.25 Vrms in RCA. This fine adjustment makes it possible to match gain to the sensitivity of the amplifier or connected active speakers, and to avoid input clipping or, conversely, too low a level.

Volume is managed through digital attenuation over 100 steps. This function allows direct connection to a power amplifier, without going through a dedicated preamplifier.

Linear power supply and circuit separation

The power supply is fully linear: a toroidal transformer with multiple windings feeds several independent LDO regulators. The digital and analog circuits are carried on physically separate boards inside the chassis, a standard precaution in high-end Hi-Fi to limit contamination of the analog signal by digital noise.

Construction and anti-vibration feet

The chassis is CNC-machined aluminum. Its dimensions (330 x 267 x 97 mm for 5.6 kg) place it in a generous but reasonable desktop format, consistent with the rest of the N series.

The MA-DAMPER PRO feet, developed in collaboration with Audio Bastion, stack five materials (aluminum, stainless steel, rubber, isolation balls, composite cork) to form a multilayer damping system. This type of mechanical decoupling is intended to reduce vibrations transmitted by the furniture or rack.

A link in a modular ecosystem

The ND-1 makes full sense within the N series: paired with the NT-1 transport as a source (preferably connected via IIS-LVDS), the downstream NA-1 headphone amplifier, and optionally the SC-1 as a master clock. The trigger connection (6-12 V input, 12 V output) makes it possible to synchronize the power on and shutdown of multiple devices.

It also works just as well on its own, connected to any digital source via one of its six inputs, at the front end of a traditional Hi-Fi system with an integrated or separate amplifier.

Technical specifications

Audio conversion and architecture

• Dual-mono architecture based on latest-generation AKM chipset
  • Delta-sigma modulator: AK4191EQ
  • Digital-to-analog converter: 2 x AK4499EX (independent left and right channels)
• Optimized “1+2” topology for jitter reduction, channel separation, and phase coherence
• Sound reproduction with a warm and natural signature, high transparency, and very low distortion

Clock and synchronization

• Femtosecond clock with ultra-low phase noise
• High-precision DPLL circuit (inherited from the MS-1)
• External clock input
  • Frequency: 10 MHz / 50 Ω
  • Compatible with sine wave or square wave signal
  • Optimized for Matrix Audio SC-1
• Extreme precision promoting reproduction of micro-details and enhanced dynamics

Digital inputs

• Six inputs available with electrical isolation across all connections
• S / PDIF and AES / EBU (coaxial, optical Toslink, AES / EBU)
  • PCM: 16 – 24 bits / 44.1 to 192 kHz
  • DSD: DSD64 (2.82 MHz) via DoP
• IIS-LVDS
  • PCM: 16 – 32 bits / 44.1 to 768 kHz
  • Native DSD: DSD64 to DSD1024 (2.82 MHz to 49.15 MHz)
• USB Audio (Type B and Type C)
  • PCM: 16 – 24 bits / 44.1 to 768 kHz
  • DSD DoP: DSD64, DSD128, DSD256
  • Native DSD: up to DSD512
• Reduction of ground loops and interference
• Simultaneous connections possible (computer, smartphone, tablet)

Analog outputs in Op-Amp mode

• XLR (balanced)
  • Output level: 4.5 Vrms (adjustable from 0 to 4.5 Vrms)
  • Output impedance: 20 Ω
  • Signal-to-noise ratio: greater than 127 dB (A)
  • THD+N: less than 0.0002% at 1 kHz
  • Frequency response: 20 Hz – 20 kHz (± 0.3 dB) / -3 dB at 90 kHz
  • Crosstalk: greater than -145 dB
• RCA (unbalanced)
  • Output level: 2.25 Vrms (adjustable from 0 to 2.25 Vrms)
  • Output impedance: 10 Ω
  • Signal-to-noise ratio: greater than 121 dB (A)
  • THD+N: less than 0.0002% at 1 kHz
  • Frequency response: 20 Hz – 20 kHz (± 0.3 dB) / -3 dB at 90 kHz
  • Crosstalk: greater than -125 dB

Analog outputs in Lundahl transformer mode

• XLR (balanced)
  • Output level: 4.5 Vrms (adjustable)
  • Output impedance: 20 Ω
  • Signal-to-noise ratio: greater than 127 dB (A)
  • THD+N: less than 0.02% at 1 kHz
  • Frequency response: 20 Hz – 20 kHz (± 0.3 dB) / -3 dB at 85 kHz
  • Crosstalk: greater than -140 dB
• RCA (unbalanced)
  • Output level: 2.25 Vrms (adjustable)
  • Output impedance: 10 Ω
  • Signal-to-noise ratio: greater than 121 dB (A)
  • THD+N: less than 0.02% at 1 kHz
  • Frequency response: 20 Hz – 20 kHz (± 0.3 dB) / -3 dB at 85 kHz
  • Crosstalk: greater than -125 dB

Customizable sound signature

• Selectable dual analog output mode
  • Lundahl transformer: warm, analog, and rich sound
  • Op-Amp: fast, precise, and highly defined sound
• Two sound signatures available within a single converter
• Selectable alternative output levels
  • RCA: 2 Vrms / 2.25 Vrms
  • XLR: 4 Vrms / 4.5 Vrms
• Adaptation to the sensitivity of amplifiers or active speakers

Volume control

• High-precision digital attenuation with 100 adjustment levels
• Can be used directly with a power amplifier, without a dedicated preamplifier

Digital processing

• Asynchronous upsampling for jitter reduction
• PCM to DSD conversion with configurable conversion modes
• Configurable processing modes
• Improved sound density and micro-detail finesse

Power supply

• Fully linear power supply
• Multi-winding toroidal transformer
• Regulation by multiple independent LDO regulators
• Physical separation between digital board and analog board for maximum interference reduction

Trigger connectivity

• Trigger input: DC 6 – 12 V, less than 10 mA
• Trigger output: DC 12 V / 50 mA maximum

Construction and isolation

• Premium CNC-machined aluminum chassis
• MA-DAMPER PRO multilayer anti-vibration damping system
  • Aluminum, stainless steel, rubber, isolation balls, composite cork
• Advanced vibration absorption

Dimensions and weight

• Dimensions (W x D x H): 330 x 267 x 97 mm
• Weight: 5.6 kg

Integration and scalability

• Compatible with the Matrix Audio ecosystem
  • NT-1: network transport
  • NA-1: headphone amplifier
  • SC-1: external clock
  • SS-1 Pro: network optimization
• Complete modular desktop Hi-Fi system