Pick a preamp for my system: Ayre or MBL

Why not try a tubed preamp? Plenty of great choices, BAT if you want to run balanced, CAT, Emotive Audio, Deja Vu, Dehavilland, etc if you are ok single-ended. I just think a tubed preamp might add a needed dose of warmth and dimensionality to your sound. Plus they're a snap to maintain, much easier than power amps. Happy listening!

Krell EVO 222 is a great choice. I've had a 6010d and ARC Ref. 03, all good but wouldn't trade back after getting the 222. Beautiful sound and workmanship. See Ken Kessler's review located on absolute sounds uk website.

I have an Ayre K-1xe and I think it is fantastic. I also think Ayre gear pairs especially well with Avalon speakers. It's highly resolving with a great soundstage. I don't know how it would pair with Krell but I suspect well. I haven't heard the MBL. There was a K-1xe on here that was still available the last time I checked for $3900. That's underpriced so you could buy it and re-sell easily. Maybe consider trying both and re-sell the one you don't keep?

What more can anybody add after Tboooe's experience? At this level it's generally a matter of taste.

Vic