I was thinking of using these
https://www.redco.com/Switchcraft-35FM3-Front-Mount-3.5mm-Stereo-Mini.html
they would match the arms of my fostex pretty close. they need a 3/8 hole versus the stock 3/16 hole.
Or wire direct and then instead of a boot where the wires come together, use a mini xlr 4pin and do the same with all my cans. Make them modular and have multiple 5 foot cables that are 1/4, 3.5mm, 2.5mm balanced and xlr that all terminate at mini xlr 4 pin.
Im getting a monoprice thx 788 amp/dac for my birthday and want to have all my can xlr but still be able to use them on my onkyo balanced dap, basx and darkvoice.