http://www.diytube.com/phpBB2/viewtopic.php?t=1612
The DIY board is a ST-35, Rev. B. It's already assembled (thanks, Don!). I've drilled the aluminum plate and cut the holes for the tubes. I have essentially no experience with metal work. This took me about four hours just to get this far. The plate started out as an L shaped scrap. I cut the straight lines with a 10" power mitre saw. I still have another rectangular piece left over, about 14" x 9". The holes were all drilled with a hand drill mounted in a stand. I first drilled at all locations with a 5/32" bit. Then I expanded the six tube holes with a 3/4" unibit ($10, Harbor Freight). Finally, a $20 punch set (also Harbor Freight) finished the tube holes. Honestly, the unibit makes a much nicer hole than the cheap punch set. Next time I'd save the money I spent on the punch, and use it to buy a bigger unibit.
Now I need to use the dremel tool to cutout a hole for the power transformer. It needs to drop down into the chassis, like a Dynaco ST70. Before I cut, which way do I want to orient the transformer? I'd like to minimize the potential for hum. I've picked the way that will make the wiring hookup easiest, but I'm not sure this is the "right" way to minimize hum.
Here's my pictures. All the transformers are sitting on the plate upside down. The don't sit very well right side up, since their wires get in the way without any holes in the plate.
