Matrix Audio SI-1 Audio Grade Network Isolator at Vinyl Sound Buffalo, NY

The SI-1 is an audio-grade network isolator from Matrix Audio (Xi'an, China), available at Vinyl Sound in Buffalo, New York. Launched on February 25, 2026, the SI-1 sits inline between the router or network switch and a music streamer, using active optical-electrical isolation technology to create a complete galvanic break in the Ethernet signal path. A dual-channel optical transmission architecture with independent send and receive paths converts the incoming electrical Ethernet signal to light internally, severs all electrical continuity between the network and the audio component, and converts the signal back to electrical at an isolated output port. Dual femtosecond clocks reclock the reconstructed data stream after optical conversion, reducing transmission jitter. An internal linear power supply built around a dual-winding epoxy-potted toroidal transformer and multiple LDO regulators powers the optical circuits and clocks without the switching noise that would undermine the isolation benefit. Reviewed by Moon Audio, Hans Beekhuyzen Channel, Audiophilepure, and StereoNET in 2026.

Active Optical-Electrical Isolation and Dual-Channel Architecture

Most network isolators on the market use passive transformer coupling or simple galvanic separation techniques that reduce conducted noise but do not break the electrical connection completely. The SI-1 takes a fundamentally different approach: it converts the incoming electrical Ethernet signal into an optical signal using two specialized internal optical transmitters, one handling upstream data and one handling downstream data in a dual-channel independent architecture. Inside the chassis there is no metal conductor carrying the audio data across the isolation boundary; the signal travels as light, creating a true galvanic break with no path for ground-loop currents, common-mode interference, or EMI from the router to travel into the audio component. The optical signal is then converted back to electrical on the output side and delivered through a physically isolated RJ45 port that incorporates an electrical isolation washer, reinforcing the separation and eliminating any residual electrical continuity between the input and output sections. The isolated output port also features switchable LEDs on the rear panel, allowing the port activity lights to be turned off completely for dark listening environments.

Dual Femtosecond Clocks and Linear Power Supply

Optical-electrical conversion introduces a re-clocking stage: the data must be reconstructed on the output side from the optical signal, and the precision of this reconstruction determines how much timing jitter the isolator adds or removes from the data stream. The SI-1 uses two femtosecond-class crystal clocks to govern the re-clocking process after optical conversion, actively rebuilding the network signal with superior timing accuracy rather than passing through whatever jitter the upstream router or switch contributed. Most competing network isolators are passive devices that draw power from the network signal or ship with an external switching power supply, both of which introduce new noise into the isolation chain. The SI-1 uses an internal linear power supply built around a dual-winding toroidal transformer that is epoxy-potted to suppress mechanical vibration and magnetic flux leakage, feeding multiple independent LDO linear regulators that supply clean, stable DC to the optical transmitters and femtosecond clocks. The unit draws up to 15W from the AC mains and operates at all times without a power switch, maintaining thermal stability and consistent clock performance.

System Integration: Where the SI-1 Fits

The SI-1 installs inline on the Ethernet cable immediately before the music streamer, network DAC, or NAS drive it is protecting, with one RJ45 input port connected to the router or upstream switch and one isolated RJ45 output port connected to the audio component. In the simplest single-streamer installation the signal path is Router → SI-1 → Streamer. For systems that also include a Matrix Audio SS-1 or SS-1 PRO network switch, the SI-1 sits upstream of the switch as the first isolation stage: Router → SI-1 → SS-1 PRO → Streamer. The SI-1 provides upstream galvanic isolation from the router while the SS-1 PRO handles signal regularization, distribution, and femtosecond clock re-clocking across multiple connected devices. For multi-streamer installations, a separate SI-1 per streamer provides individual isolation at each endpoint. The SI-1 is compatible with any Ethernet-connected audio component regardless of manufacturer, including streamers, network-capable DACs, music servers, and NAS drives.

Key Features

• Active Optical-Electrical Isolation: Converts incoming electrical Ethernet signal to optical light internally, creating a true galvanic break with no conducted electrical path between the network and the audio component, blocking EMI, RFI, ground-loop noise, and common-mode interference at the source.
• Dual-Channel Optical Transmission: Independent optical transmitters for upstream and downstream data paths prevent signal crosstalk between send and receive channels, maintaining full-duplex Gigabit Ethernet integrity across the isolation boundary.
• Dual Femtosecond Clocks: Two femtosecond-class clocks reclock the reconstructed data stream after optical conversion, actively reducing transmission jitter rather than passing through the upstream network's timing errors.
• Internal Linear Power Supply: Dual-winding epoxy-potted toroidal transformer with multiple LDO linear regulators powers the optical circuits and clocks from a clean AC mains supply, avoiding the switching noise that external or passive power approaches would introduce.
• Electrical Isolation Washer on Output Port: A physical isolation washer on the isolated RJ45 output port reinforces the galvanic separation and eliminates any residual electrical continuity between the input and output sections of the chassis.
• Switchable Rear-Panel Ethernet Port LEDs: The activity LEDs on the rear-panel Ethernet ports can be disabled via a button, eliminating all light pollution in a dedicated dark listening environment without affecting functionality.
• Gigabit Ethernet Support: Both input and isolated output ports support 1Gbps/100Mbps/10Mbps auto-negotiation, fully accommodating hi-res audio streaming, Roon server and endpoint connections, and high-resolution file transfers.
• Surge and Transient Protection: The optical isolation barrier also functions as a protective barrier against lightning strikes, power surges, and electrostatic discharge that would otherwise travel along the copper Ethernet connection to the audio component.
• CNC Unibody Aluminum Enclosure: Matrix Design language CNC-machined unibody aluminum chassis provides electromagnetic shielding and a compact 120 x 205 x 44mm footprint at 1.55kg, sitting naturally alongside Matrix Audio streamers and network accessories.
• Universal Compatibility: Works with any Ethernet-connected audio component from any manufacturer, including Matrix Audio streamers, NT-1 and TT-1 transports, ND-1 DAC, and third-party streamers, DACs, NAS drives, and music servers.

Technical Specifications

Connections at a Glance

• 1x RJ45 Ethernet Input (1Gbps / 100Mbps / 10Mbps)
• 1x RJ45 Ethernet Output, Isolated (1Gbps / 100Mbps / 10Mbps, isolation washer)
• IEC Power Input (factory-fixed voltage)

Frequently Asked Questions

What is the Matrix Audio SI-1?

The Matrix Audio SI-1 is an audio-grade network isolator launched in February 2026 that sits inline between a router or network switch and a music streamer or DAC. It uses active optical-electrical isolation to convert the incoming Ethernet signal to light internally, creating a complete galvanic break with no conducted electrical path from the network to the audio component. Dual femtosecond clocks reclock the reconstructed data stream, and an internal linear power supply with a dual-winding epoxy-potted toroidal transformer and multiple LDOs powers the optical circuits. It is available at Vinyl Sound in Buffalo, New York.

How does the Matrix Audio SI-1 compare to the iFi LAN iSilencer or SOtM iSO-CAT6?

The Matrix Audio SI-1 competes directly with network isolators such as the iFi LAN iSilencer and SOtM iSO-CAT6. The iFi LAN iSilencer is a passive device with no internal power supply that draws power from the network signal itself, providing transformer-based isolation without active reclocking. The SOtM iSO-CAT6 is a passive transformer-coupled isolator requiring an external power supply. The SI-1 differentiates with active optical-electrical conversion for complete galvanic isolation rather than transformer coupling, dual independent femtosecond clock reclocking of the reconstructed signal, a fully internal linear power supply with no external supply requirement, and dual-channel independent optical transmit and receive paths that prevent crosstalk between data directions.

Can the Matrix Audio SI-1 be used with the SS-1 PRO network switch?

Yes, and this is Matrix Audio's recommended configuration for multi-device installations. The SI-1 and SS-1 PRO are complementary devices serving different functions. The SI-1 provides upstream galvanic isolation from the router using optical-electrical conversion, while the SS-1 PRO distributes the network signal to multiple audio components with its own femtosecond clocking, dedicated audio-grade 100Mbps ports, and built-in linear power supply. The recommended signal path is Router → SI-1 → SS-1 PRO → Streamers. For a single-streamer system, the SI-1 alone is sufficient: Router → SI-1 → Streamer.

Why does the SI-1 need its own power supply if it is just an isolator?

Most passive network isolators either draw power parasitically from the Ethernet signal or ship with an external switching power supply. Switching power supplies generate high-frequency noise that can couple into the optical circuits and clock components of the isolator, partially defeating the noise isolation the device is meant to provide. The SI-1 uses an internal linear power supply with a dual-winding epoxy-potted toroidal transformer and multiple LDO regulators to power the active optical transmitters and dual femtosecond clocks from a clean AC mains supply, avoiding the switching noise problem entirely. The epoxy potting of the toroidal transformer suppresses mechanical vibration and magnetic flux leakage that would otherwise modulate the power supply output.

Does the Matrix Audio SI-1 work with non-Matrix Audio streamers and DACs?

Yes. The SI-1 is universally compatible with any Ethernet-connected audio component regardless of manufacturer. It connects inline on any standard Ethernet cable with a standard RJ45 input and an isolated RJ45 output, requiring no configuration or software. Compatible components include any network streamer, network-capable DAC, music server, or NAS drive from any brand, including Lumin, Auralic, Naim, Cambridge Audio, Aurender, and all other Ethernet-connected audio equipment.

Where can I buy the Matrix Audio SI-1 in Buffalo, NY or the USA?

The Matrix Audio SI-1 is available at Vinyl Sound, located in Buffalo, New York. Vinyl Sound is an authorized Matrix Audio dealer serving customers across Western New York and the United States, with expert guidance on network signal chain configuration, SI-1 placement relative to the SS-1 or SS-1 PRO switch, and full Matrix Audio ecosystem integration.

What is the difference between the Matrix Audio SI-1 and the SS-1 or SS-1 PRO?

The SI-1 and SS-1 / SS-1 PRO are designed for different roles in a network audio signal chain. The SI-1 is a single-input, single-output isolator: one Ethernet in, one isolated Ethernet out. Its function is galvanic isolation and jitter reduction at a single point in the chain, specifically the connection immediately before a streamer or DAC. The SS-1 and SS-1 PRO are multi-port network switches that distribute the network signal to multiple devices simultaneously, with two dedicated audio ports, multiple high-speed ports, dual 10Gbps SFP+ fiber isolation ports, and femtosecond clock reclocking across all ports. For multi-device installations, the two types work together: the SI-1 isolates the chain from the router, and the SS-1 PRO distributes to multiple audio endpoints.