Streamer with no DAC?

If OP wants "high res services" like those available from Qobuz the amp’s DAC may be the limiting factor. A Senore microRendu server with a Schiit Modi 3 DAC would be inexpensive and yield quite good sound quality. Senore also offers the opticalRendu that provides optical to a DAC, at a higher price of course, especially if you add an UpTone LPS 1.2 linear power supply.

EMM, DCS, LINN, Lumin, Playback Designs are just some names the have streamers without DAC

Your current iPhone or a MacBook or tablet. I use all three with the option to go wired or Bluetooth through IFi Bluetooth receiver with optical out to dac. All devices auto update and if there is a major technology discovery in the dac chain that is all I have to replace.

Many DACs have USB. It's worth finding out if it's really missing or the OP just doesn't prefer USB ... which is totally understandable.

micro Rendu USB only. Add $400 for SPDIF plus power supplies, cables & time.

For a good starter just get a BluNode and go digital out. Toslink on a N100 and both on a 2i.

You didn't say whether you need wifi or can work with ethernet. If you have a wired connection, look at Sonore microRendu.

If you've built your last 2 computers, Allo is for you.
https://www.google.com/url?sa=t&source=web&rct=j&url=https://darko.audio/2019/09/allos-k...
Otherwise you'll spend more time getting music out if it than you'll save shekels.

https://allo.com/sparky/digione.html

Oops SOtM USB only.

Pro-Ject Stream Box S2 USB only. $850.

Mini DSP SHD Studio. Both plus AES & DSP $900.

Magna Mano. Both plus i2s. $750

Aurender, Lumin, more

SOtM Neo 200
$450
Got one coming tomorrow.