[Amps] Controlling blower fan speed...

[thaxton@ptgroup.com]

I'd like to hear from anyone who has constructed/ designed/jury-
rigged, a fan speed controler for the tubes in their amp.

I found a couple of squirell cage blowers that I'd like to adapt and 
control their speed for my amp.  The oem blower does about 
30cfm.  The blowers I picked up are 50 and 60cfm blowers.  I'd like 
to be able to control their speed and reduce their output when I'm 
just loafing, i.e. 500watts or less, and then have the fans crank up 
when I kick in more power, i.e. 600 to 1500 watts.  All of this 
perhaps to be controlled by a temperature sensor above and/or 
around the tubes of my amp.

Has anybody developed a methodology to do this??  Any help, 
pointers to info, real life experience, advice, would be appreciated.

thanks....

Don/N0FGK