It's also important to note that AV preamp/processors provide outputs that can be connected to a powered subwoofer. In a home theater, preamplifiers may also be referred to as control amplifiers ...

[Dane] built this excellent home theater pre-amplifier. He used [Mark Hennesy]’s pre-amp design to start with, and added selectable XLR, RCA, SPDIF and even USB audio inputs. Discrete inputs ...