Anyone looking for a good head set check this URL. B&H has them for $44.99 with FREE shipping in the USA. In my estimation these are much more confortable to wear and have as good audio characteristics as the HEIL ProSet that I never use any more.
<http://www.bhphotovideo.com/c/search?Ntt=cm500&N=0&InitialSearch=yes> =======================================================
Also available from Sam Ash for the same price with Free Fedex Ground Shipping
<http: //www.samash.com/p/Yamaha_CM500%20Headphones%20with%20Microphone_-49969751>
73, Ken K3IU
These plug right in the back of your K3 or the front with a mod to the 3.5mm connector. They work OK into your PC too, but you may have to do some tinkering with the included battery adapter or make a special connector for your other rigs. A DC bias is needed for any electret mike. I will say the CM500 sounds a lot better than the Heil headset when used on the K3. And it’s pretty comfortable on the ears.
73,
John, W1AN