I am always amazed about the amount of discussion on the subject of whether or not to use noise reduction. Maybe it's because of misinformation about how it works. The SNR's do not take out a frequency of sound like an EQ. When they are dialed in correctly they ride the music signal and take out everything over and above that, leaving the music signal intact without the nasty tape hiss. Although this may seem to good to be true, it's really not and it works marvelously! The downfall to the success of the SNR's was never about it's ability to remove tape hiss successfully, it was about it being introduced into the marketplace at around the same time as CD which made it instantly obsolete. It didn't help matters that they were also expensive technology at the time. But make no mistake they do work flawlessly. As with any hardware though, there is the potential of an operator error in using this device properly.
The next time there is a discussion of whether or not to use noise reduction, maybe the question we should be asking is, "What kind of noise reduction, and, do you know how to use it properly?" I get so tired of this blanket statement of, "Oh no don't use noise reduction because it shaves off the high frequencies and flattens the sound." When done properly this just does not happen.
I can hear it all now, HISS, HISS Must be the SoCal heatwave...