Matrix

I have a pair of Klipsch RP-160M (impulse black friday purchase) and going to stream with Chromecast Audio. I'm looking at a decent stereo receiver like the Onkyo TX-8140 mobdro kodi. I'm also looking at the Yamaha R-S500 stereo receiver and Yamaha A-S301 amplifer. If I'm using a chromecast audio, I'm not sure if there is a difference between the two

Hello I was browsing some power amplifiers and came across two types of amplifiers: mono and stereo. Can anyone please explain the differences between the two and how they would be used in conjunction with a pre-amp/DAC setup? Are there any benefits to using a mono amplifier over a stereo amplifier?