Monoblock amplifiers are single-channel amplifiers designed to drive difficult speaker loads and are preferred in audiophile stereo systems for the greater power and sound quality they deliver. Monoblocks can be either tube amplifiers or solid-state amplifiers, and because you need two monoblocks for a stereo system, they can be heavy, hot and difficult to set up in a small room. Hooking up the amplifiers themselves requires proper placement in relation to the speakers and preamp.
Place each monoblock amplifier on either side of the preamp, about 1 to 2 feet away from the preamp.
Connect the RCA cables from the preamp outputs to the RCA inputs on each monoblock. Make sure you run the left output of the preamp to the monoblock powering the left speaker, and the right output of the preamp to the monoblock powering the right speaker.
Connect the speakers to the speaker taps on each monoblock. Check the taps output rating against your speaker input resistance to make sure you are connecting the speaker to the right tap. Many monoblocks have both 8-ohm and 4-ohm output taps. If the speaker is a 4-ohm load, it has to connect to the 4-ohm tap.
If you have tube monoblock amplifiers, you can often select between ultralinear and triode mode with the flick of a switch on the back of the amps. Ultralinear gives better bass response and plays louder, but triode has a silky midrange that many listeners prefer.