If I want to send back my KSC35 to Koss to fix it, what is the process and what things I have to concern? thanks

i just got a KSC35 from a person here. As I remember people said that KSC35 is full of bass and comfortable. I do think it's really light and comfortable than KSC50. However, I feel KSC50 have more bass then 35. What's wrong?

is this still available? i found that from the old thread of HeadFi http://www4.head-fi.org/forums/show...ighlight=ksc+35 http://www.liquidations.com/Koss%20KSC35.htm

I just bought a KSC50 from bestbuy today and try it on, but the quality is not as good as i think(actually the sound is pretty bad)......does this one also need burning period ? Thanks.

can u guys give me some buying suggestion? Myt budget is <$25, i need a headphone which is portable and comfortable. After I have done some research in head-fi, it seems KSC50 and MX500 may suit my needs? or if there is some other headphone which is better than them? (too bad KSC 35 is...