Hi Larry, First off, we didn't bother about noise. We obviously recorded as hot as possible to keep it at a minimum but we didn't really need to worry that much. We were recording on 1 inch 4 track. The signal to noise was already very good. We had the greatest team of tech guys to make sure that everything was always running at it's optimum and the boards were clean. We didn't bother about noise because we didn't have to.
Two other quickies. When everyone's in you don't hear noise. I give talks these days during which I break down multitracks of some of the acts I've worked with. It's great playing guitar tracks that sometimes have more noise than note but then when mixing's completed all that's apparent is what you're supposed to hear. The other thing is that using 4 or 8 track, there are so few tracks with tape noise that it doesn't become a problem. It's when you start to get up to 24 and especially 48 that problems start to occur.