Matrix Audio ND-1

The ND-1 is a DAC with a clear point of view. Matrix Audio could have built a feature-rich converter with streaming built in, a headphone stage, a preamp section, and a list of functions long enough to justify the price on weight alone. They didn't. The ND-1 does one thing — digital to analogue conversion — and it is built around the question of how to do that as well as possible at its price point. Everything else was left out deliberately.

The result is a DAC that sits at the centre of the Matrix N Series alongside the NT-1 transport and NA-1 headphone amplifier, designed to be paired rather than to contain everything. If you are building a separates system, this is the converter the system is built around.

The Chip Architecture

Matrix chose AKM's current flagship combination: the AK4191EQ delta-sigma modulator paired with two AK4499EX DAC chips. The 1+2 arrangement means the AK4191EQ handles all the high-precision digital processing and reclocking upstream, then hands off to one AK4499EX per channel. Each converter chip is dedicated entirely to one channel — left or right — rather than sharing a single chip across both. The practical benefits are better channel separation and more consistent phase performance between channels. The SNR and dynamic range figures that result are at the top of what delta-sigma conversion currently achieves.

The AK4499EX is not a new chip, but it remains the reference point for high-performance delta-sigma conversion. What matters more than the chip selection is what surrounds it — clock quality, power supply integrity, and output stage design. Matrix has put serious attention into all three.

Clock & Jitter

The ND-1 uses a custom-built ultra-low phase noise femtosecond clock as the D/A conversion reference. The DPLL clock synthesis circuit — derived from Matrix's flagship MS-1 — also supports an external 10MHz clock input, which accepts either sine or square wave reference signals. The pairing with the Matrix SC-1 clock source is the obvious path for those who want to take the clock section further. It is not a requirement. The internal clock is genuinely good. The external clock input is there because Matrix knows some of their customers will want to go further.

Electrical isolation on all digital inputs is worth noting here too — optical, coaxial, AES/EBU, IIS-LVDS, and both USB ports all have isolation between the source device and the DAC circuitry. Ground loop noise and common-mode interference are blocked before they reach the conversion stage.

The Output Stage — Why It Matters

This is where the ND-1 does something genuinely unusual. The output stage is switchable between two configurations: Lundahl precision transformer coupling and conventional op-amp output. Both modes use the same XLR and RCA outputs. The switch changes the character of what comes out of them.

In transformer mode, the signal passes through Lundahl audio transformers in the output coupling — a Swedish manufacturer known for precision magnetics used in professional and high-end audio equipment. The result is a warmer presentation, with the density and harmonic richness that transformer coupling tends to produce. Some people hear this as more analogue-like. That description is not wrong, though it is incomplete.

In op-amp mode, the output stage is faster and more linear — sharper transient definition, cleaner delineation between sounds, higher measured resolution. The THD+N in op-amp mode is 0.0002% at 1kHz versus 0.02% in transformer mode. The transformer mode trades some measured performance for a different tonal character. Whether that trade is worth making depends entirely on what you want the system to sound like.

The point is that you have the choice, in the same box, without needing a second DAC to hear what the difference actually sounds like in your system.

Output Levels & Volume Control

Both XLR and RCA outputs offer two selectable fixed output levels alongside a 100-step digital volume attenuation. XLR runs at 4.5Vrms; RCA at 2.25Vrms. The level selection allows the ND-1 to be matched to the input sensitivity of what follows it — amplifier, active speakers, or the NA-1 headphone amplifier — without introducing gain staging problems. The 100-step volume control means the ND-1 can drive a power amplifier or active speakers directly, removing the preamp from the chain entirely if that is the preferred configuration.

Upsampling & DSD Conversion

The ND-1 has a built-in asynchronous upsampling and DSD conversion engine. In upsampling mode, all PCM is resampled before conversion — the asynchronous process isolates jitter from the source and can improve perceived detail. In DSD conversion mode, all incoming audio is converted to DSD before the DAC stage, which some listeners prefer for its effect on density and tonal weight. Both modes are configurable, and the processing engine supports different PCM and DSD conversion options. Whether or not to engage these is a matter of preference and experimentation. The option is there; it is not imposed.

Power Supply & Construction

The ND-1 uses a multi-winding toroidal transformer with multiple LDOs — a full linear supply throughout, with the digital and analogue sections on separate PCBs and separate windings. Digital circuitry sits on the lower board; the D/A conversion stage is on the upper board above it. The separation reduces interference from the digital section reaching the analogue output stage. This kind of physical and electrical separation between digital and analogue is standard at the price points above the ND-1. Matrix has implemented it here.

The chassis is CNC-machined aluminium. The ND-1 also ships with Matrix's MA-DAMPER PRO isolation feet, developed with Audio Bastion, using five materials — aluminium, stainless steel, rubber, isolation beads, and composite cork — in a multi-layer vibration control system.

Where It Fits

The ND-1 is built to sit downstream of the NT-1 transport and upstream of the NA-1 headphone amplifier or a separate power amplifier. All three units share the same 330mm width and 97mm height — they stack or rack as a coherent system. The IIS-LVDS input is the optimal connection from the NT-1 if your setup supports it, reaching 32-bit / 768kHz PCM and DSD up to 49.15MHz native — the highest resolution available between the two units. The external clock input ties into the SC-1 if you are building the full system.

It also works independently of the Matrix ecosystem. Any transport or computer audio source feeding it via USB or S/PDIF will benefit from the chip architecture, the clock quality, and the isolation design. The Lundahl transformer option is a differentiator regardless of what is upstream.

Press Recognition

The ND-1 is a recent release and formal press coverage is still building at the time of writing. We will update this page as substantive reviews are published. Matrix Audio's N Series as a system has attracted attention since launch, and the ND-1 sits at its centre. We have heard it in the context of the full N Series stack and can speak to its performance directly — ask us.

Specifications

• Type: Digital-to-analogue converter
• DAC chipset: AKM AK4191EQ (modulator) + dual AKM AK4499EX (1+2 channel architecture)
• Clock: Custom femtosecond ultra-low phase noise; DPLL synthesis circuit from MS-1 flagship; external 10MHz clock input (50Ω, sine or square wave)
• Output stage: Switchable Lundahl transformer coupling or op-amp
• Coaxial / Optical / AES/EBU input: PCM 16–24 bit / 44.1kHz–192kHz; DSD 2.82MHz (DoP)
• IIS-LVDS input: PCM 16–32 bit / 44.1kHz–768kHz; DSD 2.82MHz–49.15MHz (Native)
• USB input (Type B and Type C): PCM 16–24 bit / 44.1kHz–768kHz; DSD up to 11.29MHz (DoP); DSD up to 24.58MHz (Native)
• All digital inputs: Electrically isolated
• XLR output (op-amp): 4.5Vrms; SNR >127dB (A-weighted); THD+N <0.0002% @ 1kHz; crosstalk >-145dB; output impedance 20Ω; -3dB @ 90kHz
• RCA output (op-amp): 2.25Vrms; SNR >121dB (A-weighted); THD+N <0.0002% @ 1kHz; crosstalk >-125dB; output impedance 10Ω; -3dB @ 90kHz
• XLR output (transformer): 4.5Vrms; SNR >127dB (A-weighted); THD+N <0.02% @ 1kHz; crosstalk >-140dB; output impedance 20Ω; -3dB @ 85kHz
• RCA output (transformer): 2.25Vrms; SNR >121dB (A-weighted); THD+N <0.02% @ 1kHz; crosstalk >-125dB; output impedance 10Ω; -3dB @ 85kHz
• Volume control: 100-step digital attenuation; 0 to full output adjustable on all outputs
• Trigger input: DC 6–12V, under 10mA
• Trigger output: DC 12V / 50mA
• Power supply: Multi-winding toroidal transformer, multiple LDOs; digital and analogue sections on separate PCBs with separate windings
• Power consumption: Under 3W standby / under 50W maximum
• AC input: 100–120V or 220–240V, 50/60Hz, auto-ranging
• Isolation: MA-DAMPER PRO feet (aluminium, stainless steel, rubber, isolation beads, composite cork)
• Dimensions: 330mm W x 267mm D x 97mm H
• Weight: 5.6kg
• Manufactured: China

If you are putting together an N Series system — or just trying to work out whether the ND-1 makes sense as the DAC in a different chain — we are happy to think through the pairing and configuration with you. Call us or start a conversation on the site.