I thought I was going crazy...
I'm auditioning new heapdhones and bouncing around my music library like a madman. I would SWEAR that right in the middle of playback the right and left channels would swap randomly in the middle of songs. In a normal song this sounded like a funky audio artifact but it was noticeable.
BUT!
I was just listening to Al Stewart ~ Year of the Cat. If you're familiar with the song it starts with a piano riff TOTALLY in the right channel. 30 seconds or so in the song starts into both channels. While I was listening the first play of the song, about 10 seconds in the piano moved completely to the left channel. I stopped playback and started again. Completely normal.
I've listened to this FLAC file dozens of times via my old B+ (with the same Digi+) and 0.3. I know it's not the file. I know it's not the headphones.
Anyone else experience this?