I have a NAK PA-7A MKII amp and a CA-7A pre. They are a phenomenal combo. The phono section in the pre is in a league of it’s own. I use an AT33PTG/II cart and it’s hard to describe how utterly clean the sound is.
The one weakness the pre has is the balance control may lose contact with the left or right channel when set in the mid position. Even after proper cleaning it only lasts about 6-9 months before the problem reappears.
Both units were manufactured in 1990; I purchased them used in 1998 for $2500.
BTW: The CA-7A is not a Nelson Pass design (the amp is) but it is based on Pass technology. From the sales brochure for the CA-7A .... We developed a direct coupled output stage using a complimentary-symmetry emitter follower with a current bootstrap. Same principles as in Stasis amplification.
Best money I ever spent.