XL amplifiers use an unregulated MOSFET power supply for superior control of power. A toroid-coil transformer yields maximum power transfer with minimum losses. Careful attention to circuit design keeps RFI at low levels, so you wont hear unwanted noise when the level is cranked up. Protection circuits safeguard the amplifier when overheating and speaker shorts or improper load conditions occur. All connections and controls of the XL amplifiers are on the end panels and are easy to understand. We use nickel RCA and barrier connectors to ensure the best electrical connection for your system. Included is an external automotive type fuse that is easy to replace.