Someone point me in the right direction

strongly interested in getting a DAC for a headphone based system. The headphones are Sennheiser 600's and the headphone amp,is a Bottlehead Crack.

I would like a DAC with a USB 2 input, and probably 2 coax S/PDIF inputs. No headphone amp or preamp functions needed.

My budget is $500 but I would stretch that for something special.

I very much like the sound quality of my Simaudio 260D and would like to stay in the same sonic family. that means a big beefy sound, not necessarily laid back, but absolutely no glare.

I like my Schiit Bifrost with USB 2.0 asynch input and UBER analogue upgrade for $600. Maybe look for a used one.

Alas - it only has one spdif jack, but does have optical also

It performs exceptionally well if you use good cables

I use a $70 DH Labs USB cable - a friend preferred it to his $300 silver USB from a well known cable company on his $50k system

Something like the Signal Cable Siver Resolution interconnect should work very well with it. But the better the cable the better it sounds.

All three inputs will play files up to 24/192.

The Bitfrost is a good DAC, however does not have 2 coax inputs. Finding a DAC within budget with 2 such inputs, cambridge audio?
By the way, not adverse to used at all-
Anyone with experience with the Arcam irDac?
I finally heard the Arcam irDAC this week with Rogue Sphinx integrated, Harbeth P3ESR speakers and very good cables all around. I compared the irDAC to the Naim DAC-V1. The Arcam had very good PRaT, resolution and spatial structure. Top end was airy, midrange was smooth, bass was striding and tight. Compared to the 3x more expensive NAIM, there was a little less meat in the center with the NAIM sounding a bit more solid, but the similarities of sound between the two DACs were much greater than the differences, they both sounded great.

I will likely buy the Arcam.