the helicon mk2 400 need alot of clean power to control the bass. i am using them with mcintosh 501. ss does work better then tube with the helicon unless you are in the upper price range of a tube amp. I also noticed that the helicon are a very fussy speaker, you need to place them just right, and yes they do need alot of break in. i chose to sell mine and went a diffent rout with totem winds. the helicons will reviel a poor amp and or interconnects.
