08-04-2015, 05:56 AM
I don't think that the fan will be necessary with the LM317T, they don't run hot enough to cause trouble so long as the heat sink is of sufficient size. There are big stereo amps that handle more current then any of the semiconductors in this power supply, and all they use are large convection cooled heat sinks. I would keep the extra secondary free in case you want to add a "C" supply to the unit.
Regards
Arran
Regards
Arran