Why not batteries instead of power supplies?

@larryi 
The ones Mouser is selling are designed for UPS backup power supplies. The main thrust of development for supercaps is to use them are replacements for batteries. A lot of gear already uses small supercaps for memory retention and running clocks in DVD players and the like. They replace button cells. I've never tried anything with supercaps in an amp. I'm not sure my amp building skills are to that point yet. I'd want to try it on a pre-amp first. Make a board and just hang up a half dozen or so of the little 2.7V 100 Farad deals and see how that works. Those are cheap. 

I'm surprised nobody has brought up or suggested supercaps. Those things have insane capacity, very low internal resistance, huge voltage capacities, and charge very rapidly. A lot of you folks probably have supercaps in your digital gear already since they're replacing mounted batteries left and right. You could feed a bank of those the lumpiest, ugliest power imaginable, output those to a conventional RC filter supply, and you'd have a very clean, albeit massive power supply. 

No doubt supercaps are expensive as all hell, but when you're talking about $50,000 amps, is $3000 really all that insane when it comes to filtering a power supply? I'm not suggesting using them as primary supply filter caps. I'm suggesting using them as an additional filter stage between the rectifiers and the common electrolytics. If you've got even 200 Farad between the filter caps and rectifiers, are you going to even be able to measure the ripple? Sure, you'd need massive inrush current control, and the thing might take 5 minutes to charge up, but that's really about as close as you're going to get to a completely hassle free battery with practically none of the drawbacks.