Hello there, I'd want to build a tiny custom stereo, small enough to be mounted on a forearm. It has to receive input from two different sources: my smartphone (should act as a simple mp3 player) and a head mounted microphone. As I'm not into electronics really, I would use some help. I've read this instructable as reference: https://www.instructables.com/id/Simple-Stereo-Amplifier/ I'm not pretty sure about what kind of speakers I should use and what exact components I should need. I'd want to use two speakers and I don't really care about stereo sound, actually I would prefer mono sound. Maybe I could use one speaker for the phone output and the other one for the microphone output. I'd also like to put the amplifier distant from the speakers, since the forearm mount should be as slim as possible, so I'd put it in the back trousers pocket, if I manage to make it small enough. As you see I'm kind of confused, I have ideas, but not knowledge. Have you got any guide or whatever I could use? Thank you for your help!