morricab I find it very difficult to believe a ZX-9 can make a recording that is nearly indistinguishable from the source, in fact I know it can’t. The reason I say this is because older Nakamichi decks like ZX-9, Dragon, 1000ZXL etc have a sound colouration to me and most people’s ears.
If you were talking about a CR-7, CR-5, CR-4 etc I would be more inclined to believe you as those decks I mentioned are some of the most neutral decks in the Nakamichi range, they impart very little of their own sound signature on the music recorded with them.
I am not saying the ZX-9 is not a good deck, it is a very good deck just that it has a colouration on the music.