I want to build a good quality hi-end tube amp able to drive 90db 4ohm speakers in an average size room. It seems that I will need at least 15-20 watts and was looking at some PSE 300B kits as the possible solution. I was wondering how much of the SE magic you lose if it is PSE. Since I am looking for a reasonably powerful amp I was also wondering about finding a 845 kit but they don't seem to be available or are not so popular in kit form. Being a newcomer to DIY valves I am still confused about the relative merits in terms of sound quality regarding different tubes. Do DIY kits compare favourably to hi-end products like Jadis,Cary etc?