The Ashly TRA-4075 is a 4-channel, 2-rack-space amplifier designed for fixed installations with modest power requirements. It uses a power-efficient Class-D design with a switch-mode power supply and features convection cooling for silent operation. With internally-mounted transformers, it can drive both low impedance loads (4/8 Ohm) and 25V, 70V, or 100V constant voltage lines simultaneously.