New Amp concept or already there?

Tesla makes batteries that can power the entire house. Tesla Powerwall. It obviously converts DC to AC for regular home appliances, but nothing prevents you from running direct DC line to your amp?

@mikhailark It may seem easy, but in reality there are multiple voltage values applied to the different parts of circuit and you can't just plug in any DC voltage into the game. There must be an amp specifically designed to work of high capacity batteries! An ordinary amplifier would have transformer with bunch of secondary coils defining all the necessary voltages before they go to rectifier. I think I should've posted this into the Tech talk.