Why not batteries instead of power supplies?

Cost!
http://www.mouser.com/Passive-Components/Capacitors/Supercapacitors-Ultracapacitors/_/N-5x76s?P=1z0x...

Wow it’s been a while, since looking at them. And you can get 48v 83 farad for a "cheap" $1,300 each you’ll need two. Great ESR as well,can you imagine the inrush current!!!!!!! No BS boutique ac voodoo fuses here, you'll need massive circuit breakers
http://www.mouser.com/ProductDetail/Maxwell-Technologies/BMOD0083-P048-B01/?qs=sGAEpiMZZMuDCPMZUZ%252bYl9uUUNJQGTDeS0ZKH5mj4e4%3d
Wonder who’s going to be the first linear amp manufacturer to start using them, my bets on Dan D’Agostino .

Cheers George

If memory recalls, I think Vinnie Rossi already uses this technique in his LIO amp, one of the reasons why it sounds so good. Two sets, one set is used while the other is charging and they switch back and forth as needed. 

I heard a system with the Veloce linestage and it sounded quite good.  I have no idea how it would compare with an otherwise identical model running off of a conventional supply.   I have also heard an ultra expensive version of a preamp that is quite similar to mine (same builder), but it ran off of a large battery pack.  It too was very nice sounding, but, it had to be recharged quite often.  It, like the Veloce, is a tube unit.  I saw pictures of a DIY tube phono stage with a battery power supply that was the size of a large refrigerator; all in the name of extremely low output impedance.

I would think that battery power would make even more sense with solid state where there would be far less draw at idle.  

Jeff Rowland Design Group offer battery powered amplification since early 90's

http://jeffrowlandgroup.com/us/preamplifiers-criterion.html

http://www.hifi-advice.com/blog/specials/jeff-rowland-company-special/jeff-rowland-battery-power-sup...