How to stream with a pre-amp

It works, beautifully. I thought the added unit would cloud the signal, but not so. Thanks again.

Then just use the Marantz as your streamer.

Thanks - that helps.

In terms of service, mostly Spotify, running the 320kbps. The Marantz AVR houses everything - it streams. Here are a few notes about the Marantz: 

HEOS, Bluetooth, Wi-Fi and AirPlay 2 Capability

Dual antenna system lets you stream the most popular music services via Bluetooth, AirPlay or the HEOS app. Listen to your playlists on Spotify, Pandora, TuneIn, Deezer and more.

Here is a link with a good summary of its skillset. I'll note the the Saga was an immediate and significant step-up with respect to soundstage, even with the stock tube, which I understand is weak compared to other options. 

https://www.audioadvisor.com/prodinfo.asp?number=MASR5013&msclkid=079bdb1ae13a1974bf5d8672f6aa69...

As long as you don't crank up the AVR to Max, There shouldn't be a problem. Yes, the Saga will just "see" it as another source.
Yes, you would plug your CD player into the Saga and output the Saga to your amp.
For an all-in-one solution, the Bluesound is supposed to be quite nice.
What are you using for a streamer now?

and YES, the AVR has a built in DAC.

Bluesound Node 2i (or a used Node 2).

OK, that's making sense... so, the AVR output would be available through the selection of a particular input on the Saga; otherwise, I would run, say, my CD straight to my Saga, on another input, and use it without the AVR circuitry, the rest of the time. I suppose the concern is how the two, the AVR and the Sage will interact. I've not run two pre-amps in series before... ?

Thanks for your help on this.

What were you using before to stream?

Does it have a built in DAC? If so, there should be analog audio outs that will connect to a Saga input.

Otherwise you will need a DAC.