Dolby NR encoding - did it ever work

I will partly correct what I said before. I think, my cartridge and new cables were not fully broken in when I was making comparisons while recording from my Spacedeck turntable, though they had over 150 hours on them.
First of all, the deck cannot really compete with the turntable. The dynamics gets compressed a little but the biggest difference is in the soundstage - it loses both depth and width, but the deck still sounds very very good. The same can be said about the difference between recordings made without Dolby B and with it. They do sound better without it even though they are noisier, of course.

If anyone ever experienced the dynamics of their recordings being compromised while using Dolby B, C or S, then your machine was not calibrated for the tape you were using. 
Once calibrated and proper recording levels set Dolby would have no ill effects on your recording. 
This is funny because I just had this conversation with another audio nut. I have hundreds of tapes many that are 40 years old that sound excellent and were made with Dolby. 
That said I do know the sound of a machine that is killing the Dynamics of your recording when using Dolby. Nearly all of my Teacs did this. It wasn't I until someone showed me their Advent 201 in which you could calibrate the Dolby that I realized how good it could be and how bad mine were. Since that time I have always owned a deck that allowed calibration of the Dolbly NR system. 
I am really surprised at the number of audiophiles who snub cassettes as 'mid-fi' crap. Properly recorded cassettes are very enjoyable and convenient. I use my ancient Nakamichi all the time with excellent results. 

I don't know, Norman, my Nak was aligned and calibrated by Willy Hermann five years ago, and I did send him Maxell Vertex tape along with the deck. But I cannot be certain what he did with Dolby if anything. The deck still sounds exactly the same as when it returned from him. The sound is definitely not mid-fi, the deck just reached its limits. As I said, the drop in dynamics with Dolby is not dramatic but quite noticeable. In any case, I don't really need Dolby, some extra noise doesn't bother me. And of course I record directly from phono to deck, I never use tape-out on the amp.

inna,

How is it that you are recording directly from phono to deck?  I know Eckart mentioned that he does this too.  You must be using some type of phono preamp out?  Yes?

Last night I calibrated the Dolby on a Nakamichi 500 Dual tracer.  It has the built in 400hz test tone for this.  After calibration, it was almost impossible to tell the difference between the source and the deck.  And this was a two head deck.  (it does benefit from the magnificent  focus gap head however).  This feature is also included in my Nakamichi 1000 MKI.

Which Nakamichi are you using?  I am certain that if the Dolby was calibrated to your tape, the result would be excellent.

Norman

Norman,
It is Nak 682ZX. I just disconnect the phono stage from the integrated amp and go directly to the deck. I of course calibrate each cassette when recording, this makes a lot of a difference.