[joms]

Some questions:
 
1) Would this be the best amp available for my K550 at the $300 price range?
 
2) Can you plug the O2+ODAC to the wall outlet indefinitely or do I need to remove the plug every xxx hours? (note: I do not plan to move the O2+ODAC. I plan to make it a permanent desktop amp/dac)
 
3) How long until the battery gets destroyed if I never unplug the O2+ODAC from the wall outlet? Will the battery get destroyed eventually or won't it matter? (is it much like a laptop that it only has xxx no. of cycles then you need to change the batteries?)

 

[ieee754]

1) I think that Schiit Modi+Magni is much better option.
2, 3) You can't use batteries with O2+ODAC combo, so it must be plugged all the time you use it.

 

[HaVoC-28]

Schiit Modi + Magni is valid alternative , but i think that you are going too far with " much better" .
 
He can also purchase a seprate ODAC and use O² with battery if needed and remove it if he use it at home .
 
Another alternative that are worth to consider : A-GD entery level (NFB-15/11) or Matrix M-stage HPA-2 USB .
 
(and others just wait for more opinions) .