Suggest on my project,PCM1794

Hello,World!
So my thesis is done.It's a PCM 1794 DAC with USB.However,I want to use it for listening too.This is my first digital project.
I'm using latest XMOS for USB->I2S.The PCM1794 is done with active I/V with LM4562 and OPA1612 for LPF.It's a bit like the datasheet schematic,just with lower gain on transimpedance amps.It works alright,and I'm pleased with the sound.It's much more detailed than my modded AP2496,however,I always want more,and 3 of my favorite AD8599 opamps are yet to come.Sound is a bit defocused now.
What else to make it better?I'm powering the analog part with LM317/LM337,7805 for +5V,and some unknown 3.3V regulator for digital.1000uF ouput caps on these.Can you recommend me "cleaner" linear regulators?
How about the DF roll-off?What's your opinion,sharp or slow?

Pic.People love pics:


I know I can't expect optimum performance on this board,but all traces are covered with thick wire and solder,and are as short as possible.I've achieved 120 dB SNR on perfboard with my headphone amp,so why not.


Thanks for reading!

Edit:the PCM1794 accepts and plays 384 kHz?Is this normal?