As the title, I'm looking to buy a new headphone amplifier for my Sennheiser HD800. I bought them a while ago on a whim after being awarded a minor cash bursary. I currently have an old "Beresford TC-7520 USB" dac, but as far as the HD800 go, I've always felt it was like having bought the best engines possible for a car and forgetting to upgrade the tires.
So I'm looking to replace my current desktop USB DAC with a different USB DAC. I'm looking at a price point of $500 or £325. Looking for something that is both warm and detailed with low bass extension but obviously without ruining the spatial qualities that the HD800 is best for.
Any suggestions to point me in the right direction?