theres no hard rules for recording drums, as there are so many variables like the sound you want, the drum set and the room.

the three most important things are capturing your bass drum, snare and hi hats (in no particular order). so try capturing those nicely. for drums, especially a rock tone or modern sounding one, compressors play a very important role. usually each mic for each drum piece goes through a compressor (and not the overall sound going into a compressor). i think this is where your problem lies.

by the way, if its just reaching the headroom area its not too bad, as long as it doesnt clip. however, using a cheap mixer, sometimes even reaching the headroom area you can tell theres abit of distortion to the sound.