whosurfoundingfatherI am not sure if I understood you correctly. But, if you mean, the chain of connection is your [PC (usb) or digital source (optical input)] -- [Audioengine D1] -- (via line out) -- [Bravo V3] -- [your headphone]. Yes, it will work. Mind you there is also a headphone jack in the Adioengine D1 though. Also, it should be pointed out that D1 is not an Inti-amp, it's just a headphone amp + DAC (I am sure you are aware of this).
The Bravo V3 you are referring to is this one -- http://www.amazon.com/BRAVO-Audio-V3-Headphone-Amplifier/dp/B00A2QKUES ?
whosurfoundingfatherYes, but not through the headphone amp.
Connect the RCA ports (on the D1) to the 3.5mm input on your Bravo (you can also use RCA to RCA, same thing).