After leaving maximum volume with headphones on for a night, it still works without getting short circuit. I tried with loudspeakers system again and things seem to improve a lot. I couldn't hear weird sounds at all now. Maybe it's cellular problems like zerodeefex's case. However, I still can hear little distortion when dynamics getting high at mid/low frequencies sometimes though. It could be problem with modded unit I have myself or problems with connected devices so I'll investigate more.
It's not like I don't trust Vinnie but we all know there's risks after modding like iRiver said. It should work without serious problems for most of the cases but being safe before sorry isn't always bad choice. Maybe I should buy RWAK100 and test on that unit myself.
Edited by WindowsX - 3/7/13 at 10:42pm