Also very important note. This is like the thing in Korean AK100 forums:
There is a Russian hacked kernel for the AK100 that is mix of AK100's bootloader with AK120's firmware. It has gapless! iRiver made an claim that it was impossible, but they corrected themselves once this kernel came out. Also, the GUI and response time improved drastically. I'm using them right now, and they are very stable and much faster than the stock kernel. iRiver also said that they will do an "official" update that is very similar to this kernel. Damn, those Russians are skilled! Kind of pissed at iRiver, but I guess this makes AK100 more tempting. Also, this kernel allows higher output on AK100.
Link: Download: https://disk.yandex.com/public/?hash=sC3iJXa46OawouqP5e1PNrJrvLtBXxjHDljQqgr/ZZg%3D
Just put the file in root directory of ak100. Also, your firmware must be 1.33 before downloading this kernel.