BlackWolfI dont have this model but i have the previous/smaller model (the K81) and if these are anything like mine they are great for everyday use whether it be cell phone or computer or tablet. and they last... I have had mine for 5-6 years and the first 4 of those i used them almost daily. i just now am going to have to replace the ear pads but they still sound wonderful
prasanth_u42 Ohms is pretty low, and most phones will be fully capable of driving 42 Ohms. I use mine with my Nexus 4 and my computers without an amp just fine.