McIntosh MC451 Hybrid Drive Monoblock

The McIntosh MC451 is a Hybrid Drive monoblock power amplifier — a single-channel chassis that combines a 150-watt vacuum tube amplifier and a 300-watt solid-state amplifier, designed specifically for bi-amping biwireable loudspeakers. The tube section drives the midranges and tweeters (where the naturalness and stereo imaging of vacuum tubes is most audible), while the solid-state section drives the power-hungry woofers (where solid state’s control and low-end punch matter most).

The MC451 is the accessible-tier alternative to the MC901 flagship Hybrid Drive monoblock. Both use the same fundamental architecture, but the MC451 delivers 150W tube plus 300W solid state per channel instead of the MC901’s larger power reserves. For listeners with loudspeakers of moderate power requirements who want the bi-amping tube-and-solid-state character in a single-chassis package per side, the MC451 is the natural choice. Autoformer output transformer on the solid-state section delivers constant power to any speaker load; Unity Coupled Circuit Output Transformer on the vacuum tube section does the same for the tube stage.

At LMC, a pair of MC451 monoblocks drives the Sonus faber Amati Supreme in Tempe Room 4 System 3 — bi-amped with the C49 preamplifier out front. The audition is one of the most direct demonstrations available of the Hybrid Drive concept: a real loudspeaker being driven by a real tube-plus-solid-state combination against source and preamplification the amplifier was designed to work with.

At $32,000 the pair in current McIntosh pricing, the MC451 is available for audition at the Tempe showroom. Power Guard, Sentry Monitor, Monogrammed Heatsinks, Solid Cinch speaker binding posts. Balanced XLR and unbalanced RCA inputs. Walk in during business hours or book ahead for a prepared listening session in the Room 4 System 3 configuration.