Thanks for the replies. If you look a little further down in Brian256's article he mentions adding a second voltage divider circuit so that the potential can go from 8 to 4 volts using a 5k rheostat. I want to have the rheostats mounted in an unused face plate so that I can adjust the fan speed from the front of my case. My first thought was the these were audio taper not linear, but after repeated measuring I'm pretty sure they just suck. Not to mention what are the chances of buying 3 linear taper rheostats and having all three actually be audio taper.
I took the bottom cover off of one of the rheostats and though I can't describe it they look poorly made to me. I'll try finding some better ones elsewhere.
Brian256: Is it possible for 1 timer to drive 3 independant op-amps/transistor/mosfet combos? Or will the signal be too weak after splitting it 3 ways.
Thanks again.