I use a One-Spot Pro CS-7.
https://www.sweetwater.com/store/detail/1SpotProCS7
My H9 runs fine one of the 2 500ma 9V outs.. using the supplied GREEN polarity reverse cable.
There is only one adapter though.. so you might need another.
Reply To: Confirming again – Can a 1-Spot power my 2 H9s?