Howdy!
I have a little writeup and crude diagram of the setup I run on mine if anyone wants it (pics of location in sig). The "Sparky" version that is referenced in Baz's page is slightly different than mine, mostly in it's use of a 10-turn pot and a few other subtle differences. The cost for my setup varies depending on "options" used when building it (regular switch or pot-mounted switch, LED indicator or not, project board or box, etc.), but should be $20 or less. If anyone wants my stuff just send me an email at
[email protected] (or PM me with your email address) and I'll email it out (after I get home). Cheers!