Damn, no way to get around this? I keep my headphones plugged into an nfb-12 all the time as well as using the RCA output for my stax amp. Been thinking of picking up a DM+ but needing to unplug my DT880s every time I want to use the stax would be pretty inconvenient.
That is the way it is built. Headphone plugged in turns off the RCA outputs. There is no way to change that. You can have the XLR and unbalanced connected to two different devices and they will both be live if you choose.