I thought I'd mention my "mobile" 2-channel rig here.
I have Genelec 6010-A powered speakers with a Squeezebox Touch playing FLAC files from a 750 GB hard drive. All can be carried in an over-the-shoulder bag. Wonderful sound!
Alternatively the system can have the Touch going thru the DAC in the Hi-Fi Man 801. Fantastic!
And the simplest mobile 2-channel system is the Hi-Fi Man 801 just playing FLAC files from SD cards through the Genelec 6010-A speakers. VERY MOBILE. VERY AUDIOPHILE.