Also, do you have the same issue with monitor switching? That you can't switch between MIX MON and DIN MON during recording? I need to call them when I get a chance.
I just got off the phone with Tascam. They indicated the behavior was as expected, and suggested if I wanted changes to e-mail them and they would send them to the development team. This is what I wrote:
DR-680MKII:
Allow the switching between MIX MON and DIN MON while recording. The DR-680 allows this, but the DR-680MKII only allows switching while not recording; the Function button is disabled during recording, preventing accessing the setting.
DR-680 & DR-680MKII:
Change the functionality of the stereo meter (designated by L and R) so that it always displays the level being recorded to the stereo track. Currently, with both models, if you are recording DIN to the stereo track, but are monitoring the mix of inputs 1-6, there is no way to view the level of what is being recorded to the stereo track. The stereo meter corresponds to what is being monitored, not (necessarily) what is being recorded to the stereo track.
Also, for those that have 2 units, this tip may help you, depending on what other gear you (don't) have. I sometimes find myself wanting to record 8 tracks, which I can do with an external DAC, but my unit (ART DI/O) doesn't have mic preamps, so I have to use something like my Mackie to go into it. I realized that I could just use my original 680 as a preamp and DAC. Plug the mics into channels 1 and 2, set the mix level of both to 100, pan them L and R, and just leave that unit in pause record, feeding the 680MKII.