I had some interesting suggestions from the Elliot Sound forum regarding heatsinks and displays.
I am now a little worried about the character based LCD displays. I did recently experiment with a small 128×64 graphical LCD display connected to a 100mhz ARM. I could draw lines on this display seemingly as fast as I could see, so perhaps this might be the way to go. A graphical display gives me more interesting options in any case. I suspect this graphical display allows a faster data rate than the text based displays. Wastes a lot of I/O pins however and this controller is more expensive than I intended to use (but I have two so I might as well use one).
As for the heatsinks, even through I don’t really want to try to cut them – cannot cut straight with a hacksaw – I think I might try since I want to try to do all I can to make sure I can use the amplifier up to a reasonable power level without problems. I do intend to use the amplifier driven by a guitar so it has to be reasonably capable. I guess this could be easy to test once built if I am measuring temperature just by operating the amplifier in various orientations and logging temperature. If I did this I would also move the power amplifiers up to the front lhs as this is where the cooling grills in the amplifier case are. I would move the existing heatsink over to the rhs in that case.
I was also thinking today that if there is a processor in the box that it should take a more active role, so for instance using that to soft start the amplifier and to power down on over temperature or other fault condition. Pointless perhaps but fun.