I guess just a little info on where I'm at might help with suggestions.
The Stello DA220 came out in 2004. It was originally around $1200. I think I got it used from a Head-Fi friend for $750. It was, at the time, highly recommended, and reviewers often compared it to DACs that cost $3000 or more. If memory serves me correctly, it uses an AKM chip. This is connected to my Mac with a VLINK USB to SPDIF converter, since the original Stello DA220 did not have a USB input. The Stello can accept only accept upto 24/96, but upsamples to 24/192.
What I don't really know, is how 18+ years has affected the sound quality versus price ratio. I get the impression that some of the DACs out of China punch well above their weight in price, however, I have no actual reference for what that means or sounds like. This is where I was hoping some of the people here could chime in.
I was initially considering things like the Bifrost 2/64 or the ADI 2 FS, but I really don't know what I would be getting, or if those would be side-grade instead of upgrade. The Denefrips Ares also seems interesting, and I've heard people say that ladder DACs were amazing, but again, I have no actual frame of reference. From what I've been able to read and find on YouTube, I take it that they are more musical, but perhaps less detailed, or perhaps, they lack a little of the punchiness that one might find in a delta-sigma DAC.
For reference, I listen to a lot of pop music, with rock, jazz, and country sprinkled in.
For headphones, I have HD650s, HD280 Pros, UE10s, and a few other random IEMs from back in the day. For my speakers I'm running Adam Audio A7Xs with an M-Audio SBX10.
Any thoughts, reviews of products, or threads that you think might help me are greatly appreciated.