Well, I guess I'll add my 2 cents worth.
I do have one of the 680 series decks - its a 682ZX. I also have one
of ESLabs' ZX-7 restoration overhaul machines, and I have a CR-7A. I
align all my machines using Teac and Nakamichi calibration tapes, so,
they are all aligned to the same standard.
Now, as to how the 682ZX and CR-7A compare - I would say the CR-7A
makes slightly better tapes than the 682ZX. But, I'm really splitting
hairs here - they're really close. Both decks have auto calibration
features, but, it **seems** the CR-7A autocalibration is a bit more
accurate than the 682ZX's older analog (motors) calibration circuits.
I also believe the higher resolution and peak hold feature of the
CR-7A's meters allows a person to set the record levels a little
better.
That said, however, when the pre-record calibration is perfect; I
would say my ZX-7 makes slightly better tapes than either the CR-7A or
682ZX. Again, we're splitting hairs here. Regardless, the peak
performance is much easier to achieve on the CR-7A.
Mark Barrett