IT4A isolation transformer unit provides four high-quality 1:1 line-level output transformers for applications requiring the high degree of electrical isolation only transformers can provide. The primary applications for the IT4A are in sound reinforcement systems where it may be necessary to break ground loops between pieces of equipment connected with unbalanced lines. For instance, the IT4A can be used to float the unbalanced outputs of an active crossover unit that must drive long cables connected to power amplifier inputs. Transformer isolation in such situations minimizes interference from SCR lighting dimmers, radio transmitters and 60 Hz AC power wiring. Furthermore, the common-mode voltage range of a transformer makes it far more forgiving of improper connections or fault conditions than any electronically balanced or differential transformer less circuit. This makes transformer-floated outputs essential for safeguarding portable sound reinforcement systems and installations.