Matrix Audio SI-1 Audio Grade Network Isolator

Matrix Audio SI-1 Audio Grade Network Isolator

The cleanest signal in your streaming chain starts before the streamer.

The Matrix Audio SI-1 is an audio-grade network isolator that uses active optical-electrical isolation technology to eliminate the electromagnetic interference, ground loops, and network noise that travel from your router and network equipment into your streamer, DAC, or music player via the Ethernet cable. It converts the incoming electrical Ethernet signal to optical internally, creates a complete galvanic break between your home network and your audio components, then converts the signal back to electrical on a fully isolated output — delivering cleaner, more precisely timed digital data to whatever is connected on the other side. The result is the quality audiophiles and reviewers describe as a blacker background: a deeper silence between notes, greater low-level detail, and a more focused, three-dimensional presentation.

Available now at All Elite Audio, your authorized Matrix Audio dealer in Timonium, Maryland — with in-store demos, expert guidance, and nationwide shipping.

Why Network Noise Is a Real Problem in Streaming Systems

Modern hi-fi systems are increasingly built around network streaming — TIDAL, Qobuz, Roon, local NAS playback — and the Ethernet cable that connects your streamer to the network is carrying more than just data. It is also carrying the electrical environment of everything else on your network: the switching noise from your router's power supply, the ground potential differences between devices on different circuits, electromagnetic interference from nearby electronics, and common-mode noise that propagates along the cable's shield and conductors.

When that noisy cable connects directly to a sensitive network streamer or DAC, some of that interference finds its way into the analog output stage — subtly elevating the noise floor, softening transients, and reducing the sense of resolution and space in the sound. In most systems this problem goes entirely unaddressed, not because it doesn't exist, but because it isn't visible. The SI-1 makes it audible by removing it.

Active Optical-Electrical Isolation — Not a Filter, a Complete Break

The SI-1's approach to network isolation is fundamentally different from passive filtering products that attempt to attenuate noise on the electrical cable. The SI-1 uses active optical-electrical isolation: the incoming electrical Ethernet signal is converted to an optical signal using two dedicated optical transmitters — one for the transmit path and one for the receive path — which carry the data across the isolation barrier using light rather than electricity. On the output side, dedicated optical receivers convert the signal back to electrical and deliver it to the isolated RJ45 output port.

This creates a complete galvanic isolation: there is no electrical continuity between the input and output sides of the SI-1. No conducted noise, no shared ground plane, no common-mode interference can cross this barrier. The output port also incorporates a physical electrical isolation washer that reinforces the separation between input and output sections, providing an additional layer of protection against conducted interference at the physical connector level.

This is not the same as using a consumer fiber media converter, which achieves basic galvanic isolation but typically uses a noisy switching power supply and a consumer-grade clock — potentially introducing as much noise as it removes. The SI-1 is purpose-built for audio applications in every dimension.

Dual-Channel Independent Optical Paths — No Crosstalk

Standard two-wire Ethernet communication requires simultaneous send and receive paths. Consumer network equipment handles this on a shared electrical medium. The SI-1 uses a dual-channel optical transmission architecture with completely independent send and receive optical paths — one fiber for transmit, one for receive — ensuring there is no mutual interference between the two directions of data flow and no opportunity for signal crosstalk at the source of the isolation barrier. Both paths operate simultaneously and independently, enabling stable, full-duplex Gigabit Ethernet communication across the isolation barrier without compromise.

Dual Femtosecond Clocks for Data Timing Precision

After the optical conversion and isolation, the data stream on the output side needs to be reclocked before delivery to the audio component. The SI-1 uses two femtosecond-class clocks for this reclocking function — one for each direction of the optical transmission path. Femtosecond-grade oscillators provide extremely low phase noise and jitter, ensuring that the timing of the Ethernet data frames arriving at the connected audio device is as precise and stable as possible. For streamers and DACs that are sensitive to network timing irregularities, this reclocking stage reinforces the benefit of the galvanic isolation by also addressing the timing dimension of network noise.

Audio-Grade Linear Power Supply — No Switching Noise

One of the most important distinctions between the SI-1 and consumer fiber media converters or basic network isolators is the internal power supply. Most network equipment uses switching power supplies that generate high-frequency noise which can couple into sensitive audio circuits even through the Ethernet connection. The SI-1 uses a dedicated linear power supply built around a dual-winding potted toroidal transformer — the same power supply topology found in high-end audio amplifiers and DACs — with multiple LDO (Low Dropout) linear voltage regulators providing clean, stable power to the optical isolation circuits and clocking system on both sides of the isolation barrier. The toroidal transformer is epoxy-potted to reduce mechanical vibration and electromagnetic leakage. Total power consumption is under 15 watts.

Protection Against Surges, Lightning, and ESD

Beyond its audio performance benefits, the SI-1's complete galvanic isolation provides meaningful protection for connected audio equipment. Because there is no electrical continuity between the network-side and audio-side of the SI-1, a power surge, lightning strike, or electrostatic discharge event on the network side cannot propagate electrically to the connected audio component. For listeners who have invested in high-value streamers, DACs, or music players, the SI-1 provides a degree of equipment protection that a simple Ethernet cable connection offers no defense against.

Switchable Rear-Panel Ethernet LEDs

A thoughtful practical detail: the Ethernet port LEDs on the rear panel of the SI-1 can be switched off. In a dedicated listening room where low light or darkness is part of the listening ritual, the persistent activity flicker of Ethernet LEDs can be a genuine annoyance. The ability to disable them entirely — without affecting the SI-1's operation in any way — reflects the kind of consideration for the actual listening environment that is rare in network accessories at any price.

Where to Place the SI-1 in Your System

The SI-1 sits inline on the Ethernet path between your network and your audio component. The most effective placement is directly before the audio device — router or switch → SI-1 → streamer or DAC. This positions the isolation barrier as close as possible to the sensitive audio component, ensuring the cleanest signal arrives at the device.

For systems with a dedicated audio network switch, the SI-1 can be placed between the router and the audio switch (router → SI-1 → audio switch → streamer), making it the primary isolation node between the dirty home network and the entire audio network segment. Matrix Audio's own recommended chain for their ecosystem is: modem → SS-1 Pro audio-grade network switch → SI-1 → audio component. The SI-1 works equally well with any brand of streamer, DAC, or network music player with an Ethernet port.

Build Quality and Design

The SI-1 follows Matrix Audio's established industrial design language with a CNC-machined unibody aluminum enclosure that provides both structural rigidity and electromagnetic shielding. The chassis features the signature Matrix Audio perforation pattern on the sides for heat dissipation. Front-panel LED indicators show device status at a glance, and the rear-panel Ethernet LEDs can be disabled as noted. At 120mm wide, 205mm deep, and 44mm tall, it fits neatly into an equipment rack or on a shelf alongside source components. It weighs 1.54 kg — solid and purposeful without being large.

Key Specifications

Isolation Technology: Active optical-electrical isolation with dual-channel fiber transmission Optical Paths: Dual-channel independent transmit and receive optical paths Clocks: Dual femtosecond-grade oscillators for data reclocking Power Supply: Dual-winding epoxy-potted toroidal transformer with multiple LDO linear regulators Power Consumption: Approximately 15W Ports: 1x RJ45 input (1Gbps/100Mbps/10Mbps), 1x RJ45 isolated output (1Gbps/100Mbps/10Mbps) with electrical isolation washer Ethernet Standards: IEEE 802.3 (10BASE-T), IEEE 802.3u (100BASE-TX), IEEE 802.3z/ab (1000BASE-T) MAC Address Table: 2K entries Ethernet LEDs: Front-panel power and link/activity indicator; rear-panel per-port LEDs (switchable off) Surge/ESD Protection: Yes — complete galvanic isolation protects connected equipment Power Voltage: AC 100-120V or 220-240V, 50/60Hz (factory configured) Chassis: CNC-machined unibody aluminum with Matrix Audio perforation pattern Dimensions (W x H x D): 120 x 44 x 205 mm Weight: 1.54 kg

Why Buy From All Elite Audio

All Elite Audio is an authorized Matrix Audio dealer located in Timonium, Maryland — part of the greater Baltimore area. We carry the full Matrix Audio lineup including the SI-1 Network Isolator, the SS-1 Pro audio-grade network switch, and Matrix Audio's streaming and DAC components. Our team has direct experience with network audio system optimization and can help you determine where the SI-1 fits into your specific setup for the best result.

We offer white-glove service, in-store demos, and support before and after your purchase. Whether you are local to Maryland or ordering nationwide, we are here to help you get the most from your system.

Call: 443-402-5055 Text: 443-402-5064 Visit: 1921 York Rd, Timonium, MD 21093

Frequently Asked Questions — Matrix Audio SI-1 Network Isolator

What is the Matrix Audio SI-1 and what does it do? The Matrix Audio SI-1 is an audio-grade network isolator that sits inline on the Ethernet cable between your home network and your streaming audio component. It uses active optical-electrical isolation to convert the incoming electrical Ethernet signal to an optical signal internally, carry it across a complete galvanic isolation barrier, and deliver it back as an electrical signal on a fully isolated output port. This completely severs the electrical connection between your network equipment and your audio component, eliminating electromagnetic interference, ground loops, conducted noise, and grounding potential differences that would otherwise travel through the Ethernet cable into your streamer, DAC, or music player.

How is the SI-1 different from using a cheap fiber media converter for network isolation? Both the SI-1 and consumer fiber media converters achieve galvanic isolation via optical conversion. The critical difference is everything that surrounds that conversion. Consumer fiber media converters use switching power supplies that generate their own high-frequency noise — potentially adding as much interference as they remove — and low-grade clocks that introduce timing jitter. The SI-1 uses a dedicated linear power supply built around a dual-winding potted toroidal transformer with LDO linear regulators, dual femtosecond-grade clocks for precise data reclocking, a physically separated port layout with an electrical isolation washer on the output, a CNC aluminum enclosure for EMI shielding, and a dual-channel optical transmission design with independent send and receive paths — all in a single integrated unit purpose-built for audio applications.

Where should I place the Matrix Audio SI-1 in my system? The most effective placement is directly before your audio component — between your router or network switch and the Ethernet input of your streamer, DAC, or music player. This positions the isolation barrier as close as possible to the sensitive audio hardware. For systems with a dedicated audio network switch, the SI-1 can also be placed between the router and the audio switch, making it the primary isolation node for the entire audio network segment. Matrix Audio's own recommended chain for their ecosystem is modem to SS-1 Pro switch to SI-1 to audio component. The SI-1 works with any placement that puts it inline on the Ethernet path to the audio device.

Does the Matrix Audio SI-1 work with any brand of streamer or DAC? Yes. The SI-1 is completely brand-agnostic and works with any network audio device that has an Ethernet RJ45 input, regardless of manufacturer. It is compatible with EverSolo, Matrix Audio, Lumin, Bluesound, Roon endpoints, Linn, Naim, dCS, and any other streamer, network DAC, or music server. Simply connect your network to the input port and your audio device to the isolated output port — no configuration, software, or settings required.

Does the SI-1 support Gigabit Ethernet speeds? Yes. Both the input and isolated output ports support 10/100/1000 Mbps Gigabit Ethernet, fully compliant with IEEE 802.3, 802.3u, and 802.3z/ab standards. The SI-1 introduces no bandwidth limitation and is compatible with high-speed network infrastructure.

What does the dual-channel optical transmission design mean? Ethernet communication requires simultaneous bidirectional data flow — send and receive at the same time. The SI-1 uses two completely independent optical transmission paths, one dedicated to transmit and one to receive, rather than sharing a single optical medium. This prevents mutual interference between the two data directions and eliminates crosstalk at the optical isolation stage, resulting in more stable and accurate bidirectional communication across the isolation barrier.

Does the SI-1 protect my audio equipment from power surges or lightning? Yes. Because the SI-1 creates a complete galvanic isolation between the network-side and audio-side of the connection, electrical events on the network — power surges, lightning-induced transients, electrostatic discharge — cannot propagate electrically to the connected audio component. For listeners with high-value streamers, DACs, or music servers, this protection is a meaningful practical benefit beyond the audio quality improvements.

What are the switchable rear-panel Ethernet LEDs and why do they matter? The Ethernet port LEDs on the rear panel of the SI-1 can be switched off via a physical control on the rear panel. This feature is specifically useful in dedicated listening rooms where the persistent flicker of activity LEDs can be distracting during a listening session. Disabling the LEDs has no effect on the SI-1's operation — it continues to function normally. This is an uncommonly thoughtful detail for a network accessory and reflects Matrix Audio's attention to the real conditions of serious listening environments.

How does the SI-1 relate to the Matrix Audio SS-1 Pro network switch? The SS-1 Pro is Matrix Audio's audio-grade network switch, which provides multiple ports for building a dedicated audio network segment with high-quality switching and clock performance. The SI-1 is a two-port isolator — one input, one output — that provides galvanic isolation at a single point in the network chain. The two products are complementary rather than interchangeable. The recommended Matrix Audio chain places the SS-1 Pro between the router and the SI-1, with the SI-1 providing the final isolation stage directly before the audio component. For listeners who have an SS-1 Pro or other quality audio switch, the SI-1 adds a layer of isolation that the switch alone does not provide.

Is the SI-1 difficult to set up? No. Setup is completely plug-and-play. Connect your router or network switch to the RJ45 input port using a standard Ethernet cable. Connect the RJ45 isolated output port to your streamer, DAC, or music player using another Ethernet cable. Connect the power supply to the AC input. The SI-1 powers on automatically and requires no configuration, software, or network settings. The front-panel LED confirms active status and link connection.

What warranty does the Matrix Audio SI-1 include? The Matrix Audio SI-1 carries a one-year manufacturer warranty. All Elite Audio is an authorized Matrix Audio dealer, ensuring your warranty is valid and supported. For warranty questions or service, contact our team directly.

Where can I buy the Matrix Audio SI-1 and get expert advice? All Elite Audio is an authorized Matrix Audio dealer with a full home audio showroom located at 1921 York Rd, Timonium, Maryland 21093. Our team can advise on where to place the SI-1 in your specific system for the best result and how it fits alongside other Matrix Audio or EverSolo components. Call us at 443-402-5055 or text 443-402-5064. We also ship nationwide.