The Sound Devices MixPre-10 II unfortunately does not support power via USB, but either gives you power options via the battery sled or its Hirose 4-pin adapter. As normal NiMH batteries last to something like zero and the original AC/DC adapter is a bit bulky, I looked for an alternative, which I found at MyVolts with their Hirose DC adapter.
This adapter provides a 2.1mm x 5.1mm socket, so you can plug in virtually any AC/DC adapter as long as it supplies a voltage between 9 V and 18V (and of course a bit of current). For this to work, you have to set the “Ext Power” option in the “Power” menu to either “Full Range” or “12V Ext DC”.
I tested this with a Blackmagic Design 12V adapter which supplies a current of 1 A. With that I could switch all 8 inputs to 48V Phantom Power and have the NoiseAssist plugin enabled. The power meter on the home screen shows a more than 1/2 empty “green battery” when using “Full Range” and 2/3 full with text displaying “EXT”. So far so good.
Taking this setup one step further, I connected a USB-C trigger board, set that fixed to 12V output voltage (check YT for a couple of videos on how to do this) and then connected a power bank with a USB-C port. Now I can use my MixPre-10 II on the go with an ordinary USB-C power bank without having to resort to a SmartBattery along with its costly adapter.
This is it for today. Happy recording.