Monotremata wrote:Yeah I dont think USB is really up to the task of properly doing phantom power still. At least thats been my experience in the past. I know USB 3 and 3.1 will put out more power than USB 1/2 but thats amps.. Voltage wise there's some super transformer or something going on in there that jacks that 5 volts up to 48 through USB. No way in hell USB can put that out on its own.
It'd be a DC to DC converter. USB 3 is 900mA. 5V * 0.9A == 4.5W, and watts = power. I looked up the max amperage for a mic using phantom power and according to IEC standards it's 10mA. That's not quite half a watt of power at 48V. Even after conversion losses and whatnot, USB 3 should easily supply what a phantom-powered mic needs.
read before that some interfaces do have issues supplying enough consistent current for solid phantom power performance which could be what you experienced, I'm not trying to say you're wrong about having experienced problems. I will say my RME Babyface has performed flawlessly with two condensers numerous times, and even big AKG C414s only require 4.5mA of their phantom supply.
All that said, I think it will work. Though after having borrowed a friend's Live (I have an X), I plan to go with something like a Rode M3 which is said to run for 200+ hours of a single 9V battery so I don't have to worry about this sort of thing. Just need to find a preamp I can be happy with. For now I'm planning to just use my Zoom H2n and swap SD cards