I once had a 582z which I highly regarded. Are you familiar with the NAK sites? I got the following from one: My lead technician would not forgive me if I didn't mention the little tingle he gets from the 680 series. They were the epitome of Nakamichi. For years, Nak worked to perfect the classic transport. By the time the 680's were made, all the details were ironed out. Tremendous warmth with total reliability. This deck offered automatic record azimuth adjustment, pitch control, and record level calibration. Not only that, it has rack ears and can be used at half speed to make tapes that are still flat to 17kHz. This is from http://www.henge.com/~sncsns/nakfaq42.html. Also try http://www.xs4all.nl/~wheijke/nak/index1.html. Hope I helped.
