I finally got around to converting my Cav-50 to Triode..have always been a Triode preferer, this seems to make sense, and with my newly dialed in Altec Valencias this is a good combo...I would have to guess efficient spkrs a must...as for the sound; I find it Bloomier and more Rounded, less harsh and metalic...still missing something though, either mode you have to tweak the rest of the gear,Tridode is also broader, more expansive soundstage- tried NOS tubes, didn't seem to work in this rig,...