sending signal wireless from Mac to DAC- whats the best way ?

My Mac Mini => Airport Express => Benchmark DAC3 via Toslink. Airport Express is no longer available, but you might find used or refurbish one. It limits transmission to 16/44.1 You can probably find some other Airplay receivers. I’ve heard of Belkin SOUNDFORM CONNECT Airplay 2. As for Itunes - I did not like user interface. It shows icons in Smart Playlist mode for each genre, but covers part of the screen with a banner. I bought JRiver "Media Center" and it is perfect so far.

WiFi on 2.4GHz had dropouts (not enough channels) so I switched to dual ban router and used 5GHz. In my new home router is farther away and I started getting dropouts. I added TP-Link Deco XE75 Mesh router (2 pieces) and switched Mac Mini to 6GHz. Now my Main ATT router in Pass-through mode is cable connected to first XE75 that connects (6GHz) longer distance to second XE75 and then to my Mac Mini (6GHz). Mac Mini is few meters away from Airport Express (5GHz).
I use free NetSpot application to see signals on WiFi.
 

What he said.

Pick up a used node 2i. You can pick them up for 200 to $250.

A Node 3 can be found for ~$100 more.

You can airplay to them and connect to your DAC via coax.

While your at it, you can stream Internet radio for free and get trial versions of Tidal or Qobuz so you can hear and enjoy streaming. The nodes are controlled by your MAC (or your phone), but they do all the streaming, eliminating the need to send music from the Mac and freeing up your Mac.

AirPort Express, gen 3 Apple TV, WiiM mini or WiiM pro will all work.

thank you guys all for the valuable inputs. 

After long consideration I decided to rip the wall and run in wall cable. it will be way cheaper and more stable than any airplay.

Thanks !

ssg308

I decided to rip the wall and run in wall cable.

You won't be sorry. Nothing is better than a good hardwire connection, imo.

Google Chromecast Audio via optical Toslink to Mini Toslink connector.
 

https://www.amazon.com/Google-Chromecast-Audio-Gloss-J42R-UXGA/dp/B0BFXMQYJF/ref=asc_df_B0BFXMQYJF/?tag=hyprod-20&linkCode=df0&hvadid=632003173413&hvpos=&hvnetw=g&hvrand=4299003119296102866&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=1027117&hvtargid=pla-1884565225568&psc=1&mcid=ef99d3013db53e37b3a5ae7fd60a68d6&gclid=EAIaIQobChMItv7ph9erhQMVWF1yCh1MjwfpEAQYASABEgLJrfD_BwE

I just purchased an Apple Airport Express, $30, based on the response from kijanki.

Great purchase! It just works.