PA Heads For bands and duos looking for a high quality, yet compact PA mixer and power amplifier, the Yamaha EMX powered mixer range is the perfect solution. Ideally matched to Yamaha's passive PA speakers, today's EMX models feature at least 8 microphone inputs (or 12 channels when using stereo sources), channel and master equalisation and a superb array of digital effects. Many models also feature per-channel on board compression and all feature two amplifiers - used either in stereo mode or to drive mono front of house speakers and a monitor speaker.