The Catch .22 problems....
1) Since this was a prototype amp, I wanted to make sure I was fully on board with the design and any tweaks and modifications before even thinking of spending $500 each for one off custom CNC'ed metal chassis. Thus the wood box with single piece of plate on top. However, with only one piece of metal plate to act as heatsink and heat dissipation (with wood all around it insulating and trapping the heat), it really needs something else sooner rather than later to prevent so much heat being inside the chassis.
2) I really like the look of having a flat top and only the tubes themselves on display, with the trannies and everything else hidden underneath... but that just means more heat trapped inside the un-ventilated metal plate and wood chassis. Punching too many more holes in the top plate would allow more heat to escape vertically, but affects the aesthetics and look. Going to ventilated chassis plate like you see on something like the BAT amps would be ideal, but that means dis-assembly and re-assembly of prototype on another top plate... putting the trannies on top like a traditional amp would help with heat issues inside the chassis, but then you don't have the same kind of look....
3) This amp has fully regulated power supplies for *everything*... So to get a fair bit of regulation on all these supplies, you have to throw away the extra voltage as heat when it isn't being called upon... more heat trapped inside the chassis... or lots of heat being coupled to the metal plate to help dissipate it... it's not like this build is like the AMR amplifiers... they use their whole chassis (and it's all very thick aluminum and huge, heavy, and super thick copper bottoms and backs) as the heatsink... not unlike how the Butler Monads used to do things... very very expensive chassis, but the look is great and it does dissipate a lot of heat so you can still interact with the chassis without burning yourself... obviously that isn't possible with this current box setup...
4) This was first and foremost supposed to be a single amplifier project just for my own personal use. No commercial offering planned... however, if it is a killer amp and a viable product offering, it still needs to be able to commercialize it easily just in case... so do I keep it cheap in some areas for just the prototype in case we abandon it entirely and build additional prototype sets later with the adjustments in them or do you do it to this set of amps? Do you try to cobble together off the shelf parts now to get something working, or do you blow the wad and get custom wound trannies for this to make it an ideal setup now knowing that you may not even keep the prototypes let alone do something commercial down the road?
5) again, these are supposed to be prototypes... but if they end up being the final amps that I keep for years to come and we don't get $500 each custom chassis (and the labor hours to re-wire into them), then these have to look good on prominent display at my place or it won't fly at all with the better half... and they have to be kid proof to a certain degree as well since the room they will be used in will likely have prying kid hands for the next number of years...
At this point, based on the little bit of listening I've been able to do, regardless of commercial future, I'm likely going to keep these as personal amps for a while... so the heat issues and the mechanical noise from trannies needs to be fixed so we can move to the next step of tweaking parts and circuit, etc.
So, since the form factor and need to potentially re-wire are still up in the air, trying to do the inexpensive stuff first... hacking up the wood boxes was the first approach before touching the top plate... With some metal mesh over the openings cut into the chassis, it would definitely be interesting looking... again, I'd prefer not to have to drill out the top plate more, but may still have to... at least early reports are that the heat is lowered a bit more... still likely need more heat sinking capability for the regulated power supplies though...
going to try to fix the cheaper power trannies from buzzing first before coughing up the cash for custom wound ones (i.e. $$$$ saved for now)... I blew the budget on the output trannies as I figured they would have the most impacts on things.... I didn't expect the multiple Hammond power trannies to buzz and vibrate as much as they do.... . hopefully that will get resolved soon to allow better evaluation of the amp's sound itself... which so far is pretty darn good sounding, I must say.... I just needed the heat thing addressed so i could run them 24/7 to break them in and feel comfortable doing it... and reduce the mechanical noise a bit more... 95% of folks wouldn't even notice it... but it's a frequency and pitch that drives me batty......