New iMac, no more Optical out! Help with DAC, best bang for buck?


Hoping to at least match the sound quality that was coming from my Mac Pro to an older B&K 307 receiver via Optical cable out/in.  New iMacs do not have anything so USB is now the route. 
As you can imagine one can spend btween $20 and $1k+ for such a device. 

I had zero problems with my 2009 Mac Pro optical and the Mac's own DAC and my ears are pretty demanding. If I spend over $1k then I may as well get a Peach Tree et al. But right now I just want some kind of affordable medium to get my sound back while I research something for high-end and longer term.

Sound Blasters are between $50-$125 on Amazon. Anything cheaper that would make me happy? THX!!
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PS - Also would an older Airport Xpress with AirTunes work for this? I'm seeing these things on FB Marketplace going for peanuts these days, especially since most don't know how to read the model # ;)
All you need is a 2nd generation Apple Airport Exppress or 3rd generation Apple TV. These are available used for $40 to $60. You can than stream your music wirelessly from your iMac to one of these devices and use their optical output to your recieiver. Your computer can than be in any room of your house. You can use an iPhone or iPad as a remote. Very simple and works flawlessly. I have been doing this for over 8 years on 3 different systems in different rooms and never had a failure or dropout. My wife even has her own system using her MacBook Pro.
I'm running USB from an old iMac into a Schiit Modi 2 Uber then into my line stage. I'm generally happy with it. I got it for $110 used.
The Dragonfly Black or Audioengine D3 should work. Connect to inputs om you receiver with a 3,5mm to RCA cable.