I have to pick a 4ch recorder that a friend will buy for me at B&H. If I was buying it myself, I would get one, return it and get the other and do all the tests, but that's not an option.
So I have to rely on you, guys, to tell what's your experience with both of them if possible. Particularly if you used it for DSLR/Video recordings.
My main concern are the mic preamps noise and quality. Mics I would be using with be condensers (Sennheiser and AKG), lapels and radio mics. All film quality types.
The mic preamps in the DR70D mic preamps seem to be HDDA types, but that seems to be just a new name for something they already used: discrete transistors before the IC chip.
They also have an "ultra-HDD"version. But it all cooks down to one thing: preamp noise at high gain and audio quality.
The main external difference I can see between the 60 and 70 is that the latter has four XLR inputs, which allows using 4 separate XLR mics, or three mics and a time-code.
Now a very important thing. The DR60D had what seemed to be a ground-related hum when screwed to some cameras or when using the same battery to power both. Does this problem exist on the DR70 too?