You may be looking to mount a small sound recorder on your DLSR rig, maybe a Zoom H4n or a Tascam DR100.
You may also want to consider keeping the recorder off the rig as outlined in this blog post.
Our favourite mount has the recorder solid on a Cheese Plate with Arno Strap and Thumb Screw..
Or sound recorder may go onto our handlebars if you are trying to use the onboard mics..
The sound recorder mounted behind the camera on a Cheese Plate
Kept in place with a thumb screw..
But the best mount is with thumbscrew and an Arno Strap..
Seen here with recorder removed..