Used preamps under $500 better than Audiolab 8000C

The RC-1090 sounded identical in my system to the RC-1070. I don't use balanced connections. But the 1070 seemed like a better choice to me - it has no digital display circuitry to add noise to the signal. And the circuitry is more simple. The 1070 also offers tone adjustments (defeatable).

Yes indeed. The Rotel RC-1070 is a superb choice. It meets all of your criteria (including remote) and is 450-500 new. It is an amazing overachiever. I'd buy new for the 3 yr warranty. I'm using this after having owned an SF Line 1 SE, and a Rowland Consonance. I have no regrets.
Parts quality is pretty good (Rubicon caps, Alps volume etc). And it is smoother than the Audiolab (which I auditioned some time ago).