The Ashly TRA-4150 is a 4-channel, 2-rack-space amplifier designed for fixed installations requiring low impedance (4/8 Ohm), 25V, 70V, or 100V systems. It provides up to 150 watts per channel at 4 Ohms, with internally mounted transformers that allow it to simultaneously drive both standard speaker loads and constant voltage lines. It features a power-efficient Class-D design with a switch-mode power supply, uses quiet convection cooling, and includes comprehensive protection features.