With the release of the new McIntosh MC75 vacuum-tube amplifier (mcintoshlabs.com), McIntosh Labs steps back into its history. The New York–based brand, which has made great leaps in digital-music reproduction in recent years, modeled the new amp on the original MC75, a component that has been out of production since 1970. The new model is designed to drive a single audio channel of mono, stereo, or multichannel recordings. It delivers 75 watts of warm-sounding power into speakers with 2-, 4-, or 8-ohm impedances. It can be paired with vintage or modern components and speakers.