Arrr! seeing that belt clip underneath makes perfect sense......Nah, I sold my E11 about a month ago and just use DAP's alone now for my IEM's. If I were going to strap my C3 on there I would use some low profile (good strength) double sided tape sparingly in-between the amp and player. The C3 with it's touch controls would be trouble some using any kind of bands or o-ring covering those sections. The Fiio straps may fit nicely just below the screen though looking at it now.
Hohoho. Someone is on top of his new headphone models
P.S. Let's make this whole spoiler concept stick. In order to do this, just quote the picture you want to respond to, copy it, then after deleting the original "visible" quote in the editor, paste it in a spoiler (which can be accessed by clicking the black speech bubble in the top left of the editor). Bam