Hey,
I've been using this box as my pre for my applications of 4 channel with the laptop and then mics only analog out with my microtracker. I am real pleased using this thing to record 4-6 independent channels through cubase. With the laptop I power the thing with firewire as my Dell has a six pin firewire out. I have never used it as firewire out using a valence or onboard laptop battery. I will most likely have power if I patch out of a board, if not I'll use the r/c batteries for power.
I like the sound of the firebox as a pre only with my 184's,analog line out to the microtracker. I use two 7.2 volt r/c batteries wired for 14 volt and with 48 volt activated I get 2 hours and 40 minutes. I use a total of 4 batteries if I need more time. , I carry everything in a Lowe nova 4 with the mics in a pelican and the 184's in a pelican, firebox sits vertical. Very portable to carry in the field. To me on my budget it was the perfect solution, a front end that would allow me to matrix 6 independent channels and mix down after the fact and I could use it as a stand alone pre with the neumans with 12-24 volt power. I know Dirk ran his for a show using the valance to power the firebox and at 18 volt it dropped on bar on the meter
Good Luck,
Tom