With HDSLRs it is common to run the output from the recorder to the 3.5mm stereo mic in. With the H4n and DR-100, the recorder is often mounted in the camera shoe; with an MR-1 it is in a shoulder bag or pocket.
Cables are available marked for H4n and Sony with 25db attenuation, for the DR-100 with 35db attenuation. Is there something about the line out on the DR-100 that needs more attenuation?
Thanks,
David