I used mccormack dna dlx for some time, after AR vt100 mk2, and now gamut d200 mk3- the best I heard, I think that SF guanier sound sweet with a lot of amplifiers, but gamut is the best I heard, I do not think tubes are better with SF guarniere( many others thinks that tube are friend of SFG) they are only diferent, and to me gamut has more bass , sweet medios, and soft silky hihgs.I think SF guarniere is a fantastic speaker.