Ok, still haven't thrown the Mystery Deck on the AP yet. It sounds pretty awesome so I'm being lazy ...
What's the rush, right ?
Trust thy ears !
But what I am doing now is cross-checking tapes made on it with my two other main-stays.
Recorded this baby on a FeCr, no Dolby and kept the peaking around 0db ... but on play back it hits a few higher db's than that, on a few tracks.
These FeCr's are less forgiving if you push em. So I lean towards 0dB and gain a little extension in that 10k to 20k region.
One thing I'm noticing right away is that azimuth compatibility seems to be solidly in-line and the lower hiss noise attributed to the top, chrome layer is very apparent. Since the BX-300 and the 870ES don't have a FeCr position for EQ, Type I is the only game in town. No overly sibilant junk happening or weird bumps in the mid-range. The bass lines are punchy and quick. It's a live recording and it still sounds 'lively'.
The Nak was serviced by ESLabs just a few years ago and it's kicking ass with tapes recorded on the silvery, whiskered Sony... extracting all the subtle simbal hits and high-hat wisps. Oddly enough, the Sony 870 is working its magic in the bottom end, enhancing the bass and lower mids... like it usually does.
I guess I'm not such a Dolby 'required' type guy after all ...