Tekton Double Impacts

Wondering if anyone had to wait for their DI grills a long time, got used to the sound of the speaker without covers, then got the covers and noticed the sonic change. If so, what were the differences?
Well, am only interested a little, actually...
Am posting to see if I get lucky and this becomes the 4000 post on the thread. Getting close, I see....
...OH and BTW, don't forget to check your DI speaker screws after shipment. They tend to get loose in transit.

Hi Aric,
 If you were commissioned to build a cost no object SET amplifier,  for the power supply would you prefer for ultimate sound quality
1.  High quality electrolytic caps with film bypass cap or
2.  Film caps exclusively (No electrolytic at all) ?
In the signal path, very high quality coupling capacitors or an interstage transformer?  I imagine a good case could be made for either. 
As I've said before I appreciate your insight.
Thanks, 
Charles 

Would you guys quit talking over my head? :) While I don't know the differences in the different types of caps you're talking about it sure makes for interesting reading and I'm learning more all the time. 

Aric, I keep forgetting that you're a speaker designer with all we've done together involving amps and preamps. Since I love the look of the giant Duelund caps so much I think I'll make some faux ones to put on my crossover board and use less expensive caps that are actually wired to the speakers....or better yet I'll make my external crossover box look like a huge Duelund cap!

Aric, would you make an amp based on the GM70 tube? I would love to try one.

@charles1dad  Those are good questions! For a cost no object, I would likely go the exclusive film cap route in the power supply- since even the best 'lytics will tend to drift with age (however good quality modern caps last MUCH longer than those of the 70's and 80's). What I like to do in most cases, is use electrolytics bypassed with small film in the first stages where massive filtering is required, and then have the last stage be pure film since it's the last part of the filter before the audio stages. 

As far as coupling? That's another tough one. Inter-stage trafos are technically superior in the phase region (where multiple stages are required), and also when you need a step up or impedance matching transformer. However iron has it's drawbacks in terms of frequency extreme rolloffs, so you trade "possible" phase issues for "possible" response issues. However in practice using good quality parts- these issues are small and splitting hairs so long as the design is done right. 

I for one think that high quality caps can get a design that sounds phenomenal so I typically don't look into the interstage transformers much. However, on a tube that requires a huge voltage swing and lots of low current to drive it (ex: 845, 805, GM70), it's almost necessary to use an interstage trafo as there's so much in the signal path otherwise.