Best Audiophile desktop for under $2500?

If the Op wants to stick with a PC then I'd suggest a small form PC that has no fan and an external power supply. I used an optimized for streaming Asus vivo that proved to be better than a $7K streamer.

The small form fanless PC's remove the power supply from the housing. This helps with that noisy power supply and gives you options to improve the power supply. Optimizing the PC for music streaming is also advisable.  I used the Optical out but most modern DAC's have good galvanic isolation for USB now so that's not an issue anymore.

This is the thing most good DAC's have good isolation / correction of data streams etc. and I'm finding streamers to be less critical as DAC's improve. 

I've done the Optimized PC - Roon Nucleus - Aurender A10 - Chord 2go/2YU (current, I have a chord DAC) and potentially going back to an Optimizes PC. granted I have a monitor/TV in the same room and a wireless keyboard with a track pad so that makes things easier. 

To me the DAC is far more important now then the streamer attached. 

Audiophile and PC are mutually exclusive.

yep

Oxymoron.

I'm using a mini Intel i5 PC running Volumio, connected via USB-C to an SMSL SU-10 DAC.  A 2TB external SSD drive contains all my music in FLAC, DSF, MP3 and OPUS formats, and Volumio provides access to my Qobuz subscription.  I think the comments about PC and audiophile being mutually exclusive are just borne of arrogance and self-importance and are, frankly, nonsense. 

Not arrogance, just expectations based upon generally accepted principles. In high end digital, the PC is well known to be noisy especially when sharing resources with other applications. That’s why dedicated audiophile streamers are common in our hobby.