Recently I've noticed a tin-y sound when I play. I've been playing about 1 1/2 years and just recently noticed the sound. I'm not sure if the sound is new or if my ears are improving with the better I get. I have a Mitchell. It was $100 or so. I don't have the band of it but its rates positively. Anyway, can this sound be caused by strumming a certain way or do I need new strings? Not sure what to do. Thanks