Upgrading Tube Preamp from Audio Research LS-7 - Recommendations for better soundstage?

I want to replace my ARC LS-7 tube preamp. I fell in love with the bloom and warmth when I bought it. But it doesn't have the soundstage focus or width that I had heard from others I had demo'd at the time. I think I want both now!

Any recommendations on upgrades? - tube for sure, but something with better soundstaging - more focus and width. Open to used gear like an ARC SP-16L or Prima Luna Prologue or Conrad Johnson Classic or PV15 or Rogue 99 or??? These are just some I had seen used in the $1000 - $1500 range which is basically my budget.

Don't need a phono amp but would use one, don't need a remote but would use one.

My system.
- Digital and vinyl sources
- ARC LS-7 Tube preamp
- McCormack DNA-1 solid state amp
- Martin Logan SL3 Electrostat/dynamic woofer

Thanks much.