I own a pair of Sophias. My preamp is the ML 380 and power amp is the ML 431. While this sound is pleasing to me, I think I can do better and trade up my preamp. I will be auditioning the VTL 6.5 and other tube preamps. I've heard the Spectral pre and power amps and wasn't impressed. I've heard Krell amps and wasn't impressed either. I think the Sophias are very revealing and SS equipment might not be suited for it. If I were in your shoes I would audition tubes vs. ss amps and then decide what make to go with. Tubes will give you a bigger sound stage although the ML 431 is big too, that's why I bought it. But maybe a tube amp will make the Sophias sound smoother.