The Musical Fidelity X-CANV8P. It has the power to drive any headphone and the USB DAC is similar to the well rated MF V-DAC.
When you say you want to bring out the bass, with MF kit you get a ton of detail. You will not get floor thudding lumpen bass. So at first you may find the X-CAN a bit bass light and lacking in dynamics. Once run in, and I would say mine is now along with AKG 702s, both taking hundreds of hours, the bass detail is incredible. I can hear the kick drum and pick out times when it was not hit as hard as at other times. The bass guitar has a level of resonance I have not heard before.
The bass integrates beautifully with the lower midrange and it does not overwhelm it. The emphasis of MF kit is on the midrange, the aim being to reproduce music as accurately as possible.
I listen to a lot of prog rock of all styles and the MF approach means I get to enjoy listening to the details in the music and the musicianship.