Oh, an Orb. Hmm. Well, I guess you can't just swap out the fan, then. An alternative would be something like the
Zalman Fan Mate, which would allow you to turn down the voltage. Just be careful your fan will start up if you decide to set the volts very low (5V or something).
You could also try a simple
7-volt mod for the fan. You'd have to connect it to an adapter and run it through a molex, of course. 7-volt modding works very, very well and it's really easy to do.
Obviously, with either of these methods, your CPU temperature is going to go up a bit. Just a couple things to keep in mind if you can't find a new cooler.