Has anybody replaced the 3-speed switch on a Volcano 7+ HSF with a rheostat yet? If so, how does it do, and from where did you get the rheostat? The 7+ is rated at 0.55 amps and 6.6 W, which exceeds the specs on the rheostat that CrazyPC offers. Radio Shack doesn't seem to carry a large enough rheostat, either, at least in my area. Thanks for any help...