A monoblock amplifier is a single unit responsible for amplifying a single channel, or mono signal. Unlike stereo amplifiers, which have two independent channels for left and right audio within a single unit/chassis, a monoblock amplifier amplifies a single channel rather than being shared between multiple channels. Monoblocks are larger, heavier, and more expensive per channel than stereo amplifiers. They are typically used in car audio and higher-end audiophile systems that benefit from the isolation of separate per-channel amplifiers.

Some key differences between monoblock and stereo amplifiers include:

• Number of channels: A mono amp only supports amplification of a single channel, while stereo reproduction requires two channels.

• Form factor: A stereo amplifier is more compact than two individual monoblock amplifiers.

• Power supply: Monoblocks have completely separate power supplies, whereas most stereo amplifiers use a single shared power supply.

• Design: Monoblocks are usually a fully balanced/differential design, incorporating both push and pull, while some stereo amplifiers are balanced/differential, but most are still single-ended.

Monoblock amplifiers can be used to amplify any single channel in an audio system. If there is only one audio channel, a single monoblock amplifier is needed. If there are two channels, like in a stereo recording, two monoblock amplifiers (or a stereo amplifier) are needed. Monoblocks can also be used to amplify individual channels for playback.