Hello from NH USA, common sound issue (analog vs HDMI)

I have been using volumio for my music server for several months, but it’s had it’s issues. I have no clue how so many of you seem to know what’s going on, there seems to be no real help and nothing is ever intuitive to me. I have to have a clue what direction to go in must of the time. Right now I’m running Volumio 1.5 on a raspberry pi B attached to a stereo (as AUX). Is there any documentation on volumio? There’s this forum, a Blog I haven’t looked at in months, and that FAQ that seems to say nothing (at least from my point of view). Right now I’m trying to change over from composite video and analog stereo to HDMI video and analog stereo (no fancy DACs), but really haven’t been able to. :unamused:

I dont really understand what is the issue ?
Could you explain what is wrong, and what you 'd like to do ?

After reading between the lines I looked up how to change the audio output under Raspbian and found the answer to the question above:
amixer cset numid=3 1 #sets analog output

amixer cset numid=3 2 #sets HDMI sound output

amixer cset numid=3 0 #sets default output, generally HDMI

There is no X as volumio is based on a stripped down raspbian OS. So the unit only has command line input like above.
amixer us a command line utility that volumio does have. There is nothing that tells me that volumio has the command amixer or that it can control the audio output (analog or HDMI). Worse than that is the fact it seems to do it with magic numbers that aren’t really well defined elsewhere (that I have seen).