Im using my 5.5G iMod with no caps. Though since it was sent to RWA for the iMod, Its not direct to the pins. I believe my Fiio E17 amp already has built in caps. So I'm waiting to get a silver LOD. :D I'd love a chance to A-B the iPod a bit quicker. As it stands I really can't tell too much differance in SQ from the Headphone out to the LOD with lossless files. :/ But either way, it still sounds great to me, especially in my DT880s. :D
Can't comment on RWA iMod as they mod differently (pins not lifted off board). Caps absolutely make difference in sound depending on what are used. I heard almost no difference with the Elna caps.
Your iMod has no internal caps but your Alo LOD has, then your amp also has the dc blocking caps. My amp has NO dc blocking caps, now I also tested with no caps from the dac all the way to the amp input. I don't know how Nick designed the UHA-6S, but he sure made it clear to me the amp can handle a few volts of dc offsets from input without actually having the dc blocking caps in the amp. That's awesome.