Stereo pre-amp with AV processor?

By using a separate Stereo Pre-Amp vs 2 Channels of a AV PrePro you should notice an improvement and at the very least you will be able to run only the 2 Channel side of your system and not consume power for components not in use. That alone should aid in cleaning the signal path. I have been doing this for years and plan to continue till I die or go deaf which ever comes first. Make sure that the Stereo Pre has Unity Gain AKA HT pass thru , that allow the passing of the front channel signal and all volume is controlled via the AV ProPro.
As a suggestion I would consider not going with the same brand on both Pre amps, otherwise the benefits would be minimized by maintaining the “house sound”. Perhaps Tube on the 2 Channel?

That's kind of what I'm thinking, only I'm using an integrated that I don't want to change or break.

The Anthem receiver (or Marantz) would give me HDMI switching + 3 more channels for movies.

Thanks @theo ,

Since there is no key technical difference other than the improvement of a dedicated system for 2 ch, I will try to find a way to audition the 2 cases side by side and hear the difference...

The stereo pre-amp that I am considering is $4k, so if not necessary, I other things on my wish list that may make a bigger improvement to the overall experience.

I wish to buy a multichannel DSD DAC, Kaleidescape, etc...

On another note, what brands/models of 2 channel pre-amp would you recommend?