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.
appclusive 
Hi,
Thanks for sharing this awesome information. Can you please post a photo of the full battery setup with the mixpre 10ii?
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Hi Paul, I will gladly do so. I am currently away from my eqipment for a couple of days, but will post an update beginning of Januar, if this is ok for you.
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Hi Ronald,
as the comment before, have you now a picture from the complete setup?
Am I Right that the pin from the Hirose Adapter is + and the outer ring is minus? I have to connect this correctly to the trigerbord right?
Thank you very much, also for sharing this smart idea!!!
Regards,
Mus
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Hi Mus, I thank you for your question and sorry, that I still did not upload any images of the kit. I am still away from home and will be probably for the rest of the year; something that I did not anticipate when I promised to update the post with pictures. But I can tell you, what I did:
* I took a plastic box of approx the size of the of the trigger board (later I might create a better box with a 3D printer, but this is postponed as I am currently abroad).
* I glued the trigger board to the base of the box (first “hot glue” which came off after a while and then “super glue”)
* I cut an opening into the box for the USB-C socket on the one end
* I cut another opening into the box for the Hirose cable (on the other end)
* I made some cable guard with small cable ties around the cable from the inside of the box
This worked for me; you would have to find out for yourself in a more rugged environment. Maybe you could also use “photo film capsule” (if you remember how they looked like)
Regarding the wiring: I cannot tell you by heart how the wiring has to be done, but it is easy to test it with a digital multimeter:
* According to the Sound Devices manual Pin 4 is “plus” and Pin 1 is “minus” (see page 5 of the Sound Devices MixPre User Manual).
* Verify that you have a connection of Pin1 to the minus connection of the trigger board with your multi meter
* Verify that you have a connection of Pin 4 to the plus connection of the trigger board with your multi meter
* Connection of the MyVolts Hirose to the actual trigger board can be either done by cutting the MyVolts cable and directly connect it to the trigger board, or – if you need a longer conection – just extend it with another 2.1mm x 5.1mm plug cable. Just make sure, you do not use excessive length to keep the voltage drop low.
I hope this helps. And sorry, that I cannot be of more help right now. Regards, Ronald
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