For more than 50 years, JBL's mission has been to develop and refine audio products that satisfy the most demanding enthusiast. In the studio, in concert, at the movies, or on tour, JBL is everywhere sound matters. JBL Grand Touring series amplifiers deliver pure, clean power with the soul of JBL pro gear. The GTO 75.4 features a full MOSFET PWM (Pulse Width Modulation) power supply for sag-free performance and increased output at 2-ohm loads. The "Direct Connect" terminal block power connectors allow for either 8 gauge or 4 gauge power wire, and the die-cast aluminum heat sink features a Plexiglas viewing window. Other features include variable high and low-pass crossover, high and low-level inputs, variable bass boost, and full-range preamp outputs. Drive your speakers with pure Grand Touring power and you'll know why JBL is the official brand of live music. Minimize