Me cutting the alumin(i)um bar stock.
The amp reassembled (can't live without music!). The chassis gets rather warm. It doesn't seem to cause problems (no audible cutouts - the LM3886 has sofisticated thermal management, which means that it makes funny noises when it gets too hot). I went to Frys to get some other parts and a new phone and saw this fan on special - it has a thermal feedback sensor and a blue LED (to make it cooler).