Hey Guys!
First: I'm now succesfully using 8 Eneloop cells to power the USBPre 2.
That's quite easy, I connect 4 in series (there are battery holders for exactly that), do that twice and then connect the two packs of four in parallel.
They're rated at 1.2V and what I'm measuring at the end of the whole package is 5.03V, which is great, since it's within the 5.0 +- 0.25 V that are specified by the USB standard.
I haven't done much testing yet, but since their voltage almost doesn't decrease until they're close to be empty and only then rapidly falls, they should be fine for a lot of applications. Remark: I couldn't test it with phantom power on, yet. (because I don't have any condensor mics here at the moment).
Second: Now I'd like to connect the USBPre 2 to the iPad through the "Camera Connector".
With an USB hub this works; without a hub it (of course) doesn't work.
Unfortunately it also doesn't work with my DIY battery pack.
The iPad complains that the device draws to much power when I'm attaching it.
I went further and cut the two power wires going to the iPad, so only the two data lines were connected, but still, it kept complaining.
This, while the USBPre is up and running nicely on battery power.
So what's the problem?
How to make the iPad accept the autonomously powered USBPre 2?
I'd greatly appreciate some help to get this fine combo working!