I've tried preamps and amps from various brands including Rowland, Accuphase, Ayon, Merrill, various Krells, Parasound, Rowan, Audio Research, Air Tight, EAR, custom built class D, Music First, W4S, Denon, Crown, Apart (a pro amp), Behringer, Austria Analogue, Luxman, Graaf and quite a few more.
From vintage to present day, valve and solid state, medium to high power etc.
The best Duetta driver combo I have been able to come up with is a Chinese Cayin tube preamp that beats any other preamp I have tried, together with a Luxman M-800a.