Lundahl High Level, High Impedance Isolation Unit LL156X-3FXPHM

The LL156X XLR in-line transformer unit is built to break ground loops and handle balanced-to-unbalanced conversion in mobile or fixed audio setups. Magnetically shielded, it houses a high-impedance LL1565 input transformer with low-frequency saturation above +22 dBU at 40 Hz, and the two ends of the unit are galvanically isolated from one another.

Lundahl transformers are mainly used in the output/interstage of tube amplifiers, in microphone and line inputs, and for galvanic isolation in studio and live sound systems (DI boxes, ground-loop breakers). The Swedish manufacturer winds its own copper wire and casts its own cores for every model, resulting in very consistent, factory-measured parameters even in series production. For custom loudspeaker or amplifier builds, tube amp restorations, or premium DI box projects, Lundahl transformers provide a reference-quality foundation, and most output types are available for both push-pull and single-ended (SE) stages. The brand has earned the trust of major names across the audio industry - studios, instrument and amplifier makers - over several decades, and many designers build their circuit specifically around a Lundahl transformer because the catalogue parameters (inductance, leakage inductance, DC resistance, saturation level) are reliably reproducible from unit to unit. Before installing, it is worth double-checking the exact impedance match and the available mounting space, since size and weight can vary significantly between types.

Swedish manufacturer Lundahl Transformers AB has been hand-winding custom iron-core audio transformers for more than half a century, used by leading tube amplifier designers and studios worldwide for reference-quality signal transfer.

Package weight: approx. 0,2 kg.