^^^ The jack has 3 "rings" (3.5mm) and the amp probably only accepts 2 ring jacks (2.5mm). You need an adapter. Plenty on amazon for cheap. The ue6000 doesn't work on my ipad 3 without an adapter.
Ps. I forget if the headphone splitter that came with the ue6000 is 2.5 or 3.5. You can try that.
uh, i think you've confused things...the number of rings is completely separate from the size of the plug.
you can have 3.5mm and 2.5mm plugs with 1 (mono), 2 (stereo) or 3 rings (stereo+mic/remote). 2.5mm plugs are just a completely different size...hence why they are called 2.5mm. ;)
Edited by caprimulgus - 12/15/13 at 7:17pm