I'm wondering how much success folks have had running mics directly into the DR-680 (similar question would apply for R-44 I guess but starting with 680) rather than through external preamps. Looks like a lot of sources have a preamp of some sort in the chain with the 680 as a bit bucket much of the time.
I also have zero complaints or hesitations on using the internal preamps. Below is a photo of the on-stage setup I ran last night. The three ADK TLs (all in supercardioid pattern) are routed straight into the DR-680. The small diaphram Gefell cards in ORTF are routed > V3 > S/PDIF > DR680. Not visible are three DPA 4060s (one boundarymounted on stage in front of the drumkit on the snare side- you can barely make out a small square of gaff tape on the floor infront of the center TL, and two boundary mounted to the front face of the stage under the lip, facing the audience) also direct into the DR680 via Naiant phantom powering adapters. On a quick listen when I got home, the direct-routed ADK setup beat the Gefells> V3 handily, but I don't think the different chains and preamps have much to do with the differences.
[edit- I also get no hesitation blues when deciding to use the internal pres of the R-44, but mine is Oade Concert Mod'ed, so I don't know first-hand how the stock preamps in the R-44 compare. But as far as I'm concerned the internal preamps in both my stock DR-680 and OCM R44 are equally transparent and quiet enough for my use that I just use them without thinking about it. I
can hear a difference when using the V3 and it's ADC, but the sonic differences are subtle minor and usually of less impoartance than the practical issues of eliminating the need for external preamps unless I need one to get use of all 8 channels into the DR-680]