Radial Twin-Iso 2-Channel Balanced Line-Level Isolator

Radial Twin-Iso: Silence Ground-Loop Hum on Balanced Lines

The Radial Twin-Iso is a two-channel balanced line-level isolator that inserts between any two pieces of professional audio gear to eliminate the hum and buzz caused by ground loops. At its heart sit two premium Jensen transformers, which pass your signal magnetically while breaking the ground connection that lets noise circulate. Because it is a purely passive device, it solves the problem without adding a power supply, a fan, or a single microvolt of its own noise. For an engineer chasing a mystery buzz across a stage full of gear, the quiet that follows the Twin-Iso feels like the room finally exhaling.

What a Ground Loop Is and How Isolation Ends It

A ground loop forms when two connected devices sit at slightly different ground potentials, so a small current flows through the cable shield and shows up as audible 50 or 60 Hz hum. The Twin-Iso interrupts that current by replacing the direct copper path with a transformer: audio energy crosses the transformer magnetically, but the DC ground connection does not, so the loop has nowhere to circulate. A ground lift switch can additionally disconnect the shield, giving you a second tool for the rare cases where even isolated grounds still couple. The hum is removed at its source rather than filtered after the fact.

Why the Jensen Transformers Matter

Isolation is only useful if it leaves the music intact, and this is where the Jensen transformers earn their keep. They deliver a frequency response of 10 Hz to 50 kHz within a single decibel and a total harmonic distortion figure of just 0.001% at +4 dBu, so the isolated signal measures essentially identical to the source. Their generous core also withstands input levels up to +21 dBu before saturation, meaning even the hottest console or amp-rack feed passes through cleanly. In practice the Twin-Iso behaves like a straight wire that happens to block noise.

Built for the Professional Signal Chain

The Twin-Iso carries two balanced XLR inputs and two balanced XLR outputs with matched 600-ohm impedances, dropping straight into the +4 dBu world of consoles, amplifier racks, remote broadcast towers, and multitrack recorders. Insert it wherever two systems meet and disagree about ground, and it reconciles them without repatching the rest of the rig. Its dual-mono design keeps left and right fully independent, preserving stereo imaging and channel separation while it works.

Everyday Isolation Problems It Solves

Isolating two mixing consoles is routine in touring, where an opening act sets a submix and feeds it into the headliner's board; the Twin-Iso keeps those two systems from fighting over ground. It quiets the buzz that appears when gear on different power circuits meets at an amp rack, and it tames the noise that vintage studio equipment introduces through less-than-ideal grounding. In each case a single insert point replaces hours of chasing wiring gremlins.

Who the Twin-Iso Is For

The Twin-Iso is a problem-solver for front-of-house and monitor engineers, broadcast and install technicians, and studio owners who run vintage or mismatched gear. Anyone who has ever heard a stage go quiet the instant the right isolator lands in the signal path knows how valuable that transparency is. Passive, transparent, and built to disappear into the rig, the Twin-Iso is the tool you reach for when a balanced line has picked up a hum it should never have had.