Appropos your comments about Ralph, Tvad, I have spoken to him today and he confirms his generalisation that 8 ohm impedances are better for all tube amps; however, he believes that he should re-state his assertion, since it is taken too literally (I don't want to put words in his mouth and maybe he will chime in here) - he believes the MA-2 can easily drive the Tyler Woodmere, with its benign impedance curve, but states that it would sound even better with an 8 ohm, rather than 4 ohm, impedance. So that doesn't disqualify a 4 ohm speaker for mating with the MA-2, since the speaker's 91 db sensitivity will compensate somewhat. But the Woodmere doesn't have a 60 day trial like the Zu Definition, so a trial could be "hazardous", and I've done that once already..........I suppose to get as close to "perfection", all the known criteria should ideally be met, and a higher impedance than 6 ohms is one of them, so your point is valid.
