So, I am using a XR18 and want to run the bus sends to headphones instead of monitors.  Are the mic input / through parallel?  If so I could use a standard XLR cable as a feed instead of building fem/fem adapter cables.  I assume I would hear the mix (albeit mono) in both sides of the headphones?  Using headphones would reduce noise picked up by the vocal mics when we record rehearsals.  This is the primary objective but could be applied live to in-ear applications as well.

IT IS SUPPOSED to be straightforward but for now, I don't know what's wrong with the setup. So I purchased the AMP800. I connected behind the AMP800 an "unbalanced" (one line on the connector) stereo L/R cable that I plugged a " balanced " 1/4 to 3.5mm cable to my cellphone plug (this is the source, the music from my cellphone). After that I connected in front of the AMP 800 (on channel A or 1) a "balanced" (2 lines on the connector) stereo 1/4 to 3.5mm adapter for my Bose headphones (the bose uses a 3.5mm plug). I tried so hard to figure out how to have a clean sound but nothing is working, the sounds is not clear nor high. When I pull a little bit the 1/4 to 3.5mm adapter, the sound is more stronger then when the adapter is fully pushed-in in the A or 1 jack hole. Do you have any solutions to the problem? Thank in advance :)!!