The McIntosh MC901 is a dual-mono amplifier that combines a vacuum tube preamplifier with a solid-state power amplifier in one chassis. It can deliver up to 300 Watts into 8 Ohms for the solid-state section and 600 Watts into 8 Ohms for the tube section. The MC901 is designed to be used with a pair of speakers that have separate low and high-frequency inputs, allowing it to power the speakers' different frequency ranges independently.