Matrix Audio SU-1 USB Isolation Switcher

The Matrix Audio SU-1 is a USB isolation switcher: three USB inputs, two isolated USB outputs and a linear power supply in one aluminum box. A dedicated digital isolation chip separates data, power and ground between your source and your DAC, so ground loops and computer-borne noise stop at the SU-1, and a single front-panel button chooses which source feeds which converter.

Key Features of the Matrix Audio SU-1

• Full Electrical Isolation on Every Path: A dedicated digital isolation chip separates each signal path and isolates grounds, breaking the data, power and ground lines at both ends of the link.
• Three Inputs, Two Outputs: One USB Type-C input (C1) and two USB Type-B inputs (B1, B2) feed two isolated USB Type-A outputs (A1, A2).
• High-Speed USB Throughout: Every input and output runs at 480 Mbps High-Speed USB.
• One-Button Control: A short press cycles the three inputs, a long press switches between the two outputs, and five status LEDs show the active route.
• Up to 8 Meters of Cable: Up to 4 meters on either side and 8 meters combined, with the transmission impedance tuned to hold the signal over the run.
• Linear Power Supply: A fully encapsulated toroidal transformer and multiple ultra-low-noise regulators, in place of the switching supply found in general-purpose USB hardware.
• Clean 5V / 1000mA Bus Power: Connected devices are powered from the SU-1's own supply, with real-time load detection that cuts the output on an overcurrent or short circuit.
• Surge and Lightning Protection: The isolation barrier also guards connected equipment against surges and lightning damage.
• CNC Aluminum Housing: Full aluminum-alloy chassis, 120mm wide and 44mm tall, weighing 1.58kg.

How the Matrix Audio SU-1 Breaks the USB Connection

The SU-1 separates your source from your DAC electrically while letting the music data through. A dedicated professional-grade digital isolation chip splits each signal path and isolates grounds, physically breaking the data, power and ground lines at both ends, so the two components no longer share a ground plane.

A USB cable carries power and ground alongside data, which is why a computer and a DAC joined by one end up tied together electrically. Matrix connects host and slave in series through that isolation stage and cites the results: a higher background signal-to-noise ratio, ground loops broken so loop noise is eliminated, fewer transmission errors, and high-frequency interference kept out of the converter. The same barrier stands between your DAC and anything arriving down the line from a lightning strike or a power surge.

Three Inputs, Two Outputs: One Box for Several Sources

The SU-1 is a switcher as well as an isolator. Two USB Type-B inputs and one USB Type-C input accept three sources at once, and two USB Type-A outputs can feed two DACs or digital audio interfaces, all at 480 Mbps High-Speed USB, so nothing gets unplugged when you change devices.

Most USB isolators sit inline on a single cable. With the SU-1, a computer, a streamer transport and a tablet can all stay connected to the same system, and a second converter or interface can hang off the other output. Matrix specifies full electrical isolation on the input and output ports alike.

One Button, Five LEDs: Operating the SU-1

Everything is controlled from a single front-panel button. A short press cycles through the USB Type-C1, Type-B1 and Type-B2 inputs, and a long press switches between the Type-A1 and Type-A2 outputs. Three input LEDs and two output LEDs light to show the active chain, so the current route reads at a glance from the listening seat.

What Connects to the Matrix Audio SU-1?

Anything that plays music over USB on the source side, and any USB DAC or digital audio interface on the output side. Matrix names USB-equipped digital audio transports, Mac and PC computers, and phones and tablets as sources. Each input draws less than 5V / 100mA from the connected source.

Impedance Tuning and the 8-Meter Cable Budget

Matrix optimized the SU-1's USB transmission impedance to reduce signal loss over long runs. A single cable on either side can run up to 4 meters, for up to 8 meters in total across input and output, without data attenuation or packet loss, so the source and the DAC do not need to sit next to each other.

USB was specified for short runs, and long or poorly matched cables cost signal integrity before they cost you sound. In practice a computer across the room can sit 4 meters from the SU-1, with another 4 meters to the converter. It is the difference between siting the SU-1 where it belongs and siting it where the cable ends.

Linear Power, Not Bus Power

The SU-1 runs from the wall through an IEC inlet and a linear supply built on a fully encapsulated toroidal transformer with multiple ultra-low-noise regulators. It powers connected USB devices at 5V / 1000mA from that supply rather than from the host computer, and draws less than 15W.

That matters because computer bus power is one of the noise sources an isolator exists to remove, and a switching supply in the same role would reintroduce high-frequency noise into the circuit doing the cleaning. Built-in real-time load detection watches the output and cuts it fast on an overcurrent or short-circuit fault, protecting the gear downstream. Mains voltage is fixed at the factory, either 100-120V or 220-240V.

CNC Aluminum Chassis

The housing is full aluminum alloy, CNC machined, measuring 120mm wide by 205mm deep by 44mm tall and weighing 1.58kg. Those are the same external dimensions as the Matrix Audio SI-1 network isolator, so the two stack or sit side by side as a matched pair. The side panels carry a field of circular perforations for ventilation. The SU-1 ships with a power cable, a user manual and a warranty card.

The Listening Room Difference

We're a third-generation family business with a brick-and-mortar showroom in Chestertown, Maryland, and a reputation built on exceptional service and relentless passion for hifi. Whether you're visiting in person or ordering online, we bring decades of experience, personalized service, and honest guidance to every interaction. We don't just ship boxes. We help build systems, answer your questions like real humans, and make sure every detail of your setup is right, from the cables to the final connection. Our passion is helping you get the most out of your gear, with support that lasts well beyond the sale.

Matrix Audio SU-1 Specifications