Need suggestions on preamp

I’m mainly a headphone listener so when I got the chance to purchase a pair of Magnepan LRS speakers near my home town, I ran with it. I love Maggies and their midrange smoothness and live performance feel. I was able to find a used Parasound A21 for $1200 on Marketplace which was replacing my Adcom 545. I’m now running into a dilemma where I think the Adcom 545 sounded more detailed to me. I listen to a lot of instrumental music that I know well and I’m not getting the same level of detail as I’m getting with my headphone setup which is running balanced from my RME ADI-2 DAC. I’m using more expensive Audience AU-SX interconnects on those but even when running the RME direct into the amp (since it has volume control) I’m not getting the level of resolution I’m used to with my headphone setup (Hifiman HE1000 with a Serbian Audio HSA-1B amp).

I think the issue might be related to my preamp. I bought a Schiit Saga+ and despite running good NOS tubes or trying out passive mode I’m not getting the resolution I’m looking for. I’m looking for a recommendation on a preamp that costs between $1,000-$2,000 that will max out the resolution of the Parasound while keeping it’s effortless flow and naturalness in tact. Maybe the problem is the speakers and I really should have gone for the LRS+ or 1.7s? I know the room plays a huge role with Maggies but I live in a small apartment so for now I’m looking for any suggestions that can be fixed with gear. Thanks for any help!