I am interested in getting a gaming headset, and I do not want to pay the extra money to get a USB headset. The current set I am interested in, the Sennheiser PC 151, isn't USB, and I heard from one review that you must have a USB connection to use the mic on your Mac: "The microphone is not powered and my Intel Mac requires a powered microphone in the Mic Input jackslot. I had to acquire a USB adaptor, but then it worked perfectly. These do not come with a USB plug, only mini-jacks." (http://www.amazon.com/Sennheiser-PC151-Headset-Cancelling-Control/product-reviews/B000NOR89Y) Another review said that the headphones worked fine on their MacBook Pro, though, so I am confused. Would I be able to use the headset and mic (PC 151) without any trouble on my 2008 iMac? Thank you for your help .