I also have an older Super Pas4i preamp that will never leave my system. I pretty much agree with Recordho as far as transparency but, when it comes to imaging, realism, layering and, 3D'ism (If such a word exist's), it clearly keeps up with the big boys. By the way I have tried many 12AX7's in this unit and, prefer early to mid 50's RCA,GE, and Telefunkens. Lastly... the excellent MM phono input and, tape in/outs for my vintage Nakamichi deck was the closer for me.
