Is it possible to take the 2 balanced channels out from the Dual Pre into a single stereo 3.5 TRS (for the GH3)? I'm not having much luck finding the appropriate Y cable, since i'm not sure what will happen with the ground on the balanced output.
Well yes if you first unbalance the outputs with a balancing transformer, and probably also put an attenuator on the outputs since the malanced ones are probably +4 and the unbalanced are -10. That is a 14dB difference... a LOT.
I'm not familiar with the GH3 but most DSRLs only input unbalanced mic level, so as Scott stated, you would need a balanced> unbalanced transformer/adapter and attenuation... typically 50dB from a +4dB output.
Beachtek do some input boxes that would solve your problems.....
I have the basic version in my 'pro' audio kit and used it many times into DSLR's, video cameras and pocket audio recorders.
the Beachtek looks like it would do the job. I didn't mention this, but I'd like to be able to use this on an AF100 also, with the separate xlr outs.
a yamaha mg06 would be perfect, except it requires 12v external power.