Hi Richard,
Thank you so much for this!
I have another question (BTW, the question is for everyone). First, just to be clear, I also worship Nakamichi as God's gift to the world of cassette and the Dragon was definitely a phenomenon. However, the manual states:
NAAC (Nakamichi Auto Azimuth Correction) is the first system capable of extracting every bit of information stored on cassette.Obviously, it cannot reproduce what had never been recorded, but, if there is treble energy on the tape, NAAC will bring it to you with full fidelity and clarity even if the tape has been recorded with improper azimuth!
If we assume that a given cassette was recorded on another machine with improper record head azimuth, then how can there be any substantial high frequency energy in the recording at all?
Therefore, if, instead of playing this cassette on the Dragon, we play it on any other machine with perfect playback head azimuth alignment but without NAAC, are we gaining any high frequency content? Yes, there will be phase error between the two channels.
Now, let us suppose that we digitize this cassette from the machine with perfect playback head alignment (without NAAC). Then suppose we apply azimuth correction processing such as Izotope RX dynamic auto-azimuth correction to correct the phase issue.
Will the result be substantially different from digitizing from the Dragon (purely from the azimuth point of view)?
Regards and best wishes,
Abhimonyu [log in to unmask], India    On Tuesday, 7 May, 2019, 12:12:17 am IST, Richard L. Hess <[log in to unmask]> wrote:  
 Hi, Abhimonyo,

Look on P4 for a description of how the auto azimuth works.

This machine does not physically flip the cassette,  but has dual 
capstans that apparently do the offset properly for which direction the 
tape is traveling. The machine only records in forward, but plays back 
due to it's six-track play head--the right channel of each side is 
actually two heads as explained above, in order to do auto azimuth. It 
works reasonably well on high-quality material and nothing sounds as 
good IMHO. I have seven.

On 2019-05-06 2:52 a.m., Abhimonyu Deb wrote:
>  Does anyone have first hand experience with the Nakamichi Dragon? I was young at the time, but I remember that it had auto azimuth control in realtime by splitting the right track into 2 signals and comparing the phase between them.
> I think this was the model that also had a robotic arm to flip the cassette for auto reverse instead of rotating the record / playback head.
> Abhimonyu DebKolkata, India

Richard L. Hess                  email: [log in to unmask]
Aurora, Ontario, Canada                            647 479 2800
Quality tape transfers -- even from hard-to-play tapes.