Sonically, what's the difference between the Torii jr and the MK IV, besides the small bump in wattage. Anyone make the switch?
Mike

I have owned both. The Torii Jr. for four years. And, currently I own the Torii Mk IV. They sound fairly similar to my ears, the difference being my TJ used EL34s and my Mk IV uses KT66s. The power difference is not noticeable.
The biggest difference is the Mk IV has more features, e.g., treble adjustment, bass adjustment, etc. Those features plus the Mk IV's dual mono design likely drive the cost difference between the two.