The stuff I am talking about is related to the first two or three albums. The post I started at Stephen's forum was titled High End Fizz. If you listen to the vinyl from back then, you can hear a distinct distortion/fizz to Lennon's vocals. Anyway, it took Stephen weeks to respond, as was customary for his posts. But the guy new the recording process used on those albums inside and out, and he laid it all out.
There were about twenty reasons for what I was hearing. and I wish I could remember them all because they were very interesting. All the way from tape used, what order they bounced tracks in, level of the vocals, equipment used, equipmemt mods, microphones, Lennon's vocal style compared to Paul's, what they were smoking, what they were drinking, on and on. It was very facinating to say the least. I think Stephen even had some original tapes from back then. How he got them, I do not know.
I think I remember something like a vocal guide track was recorded with the instruments, so that as the instruments were bounced, the vocalist had something to guide them during overdubs, and on some of those old tracks, you can even hear some faint vocal guide tracks left over.
On the stuff where the vocals were done at the same time as the instruments, by the time the instrument tracks got bounced three million times, the vocals were beat to death, so they had to go over them. And the interaction of the overdubs with the guide tracks were causing some problems. If they was no high end left by the time they starting compressing the hell out of the tape, then the dynamics really were lost, so they jacked up the treble a lot on the vocals.
Also, since George had to bounce tracks before the vocals could be overdubbed, there was a lot of time where the boys were just sitting around doing nothing and getting pissed. So I think they developed a deal where they could do the over dubbing on a different machine while George was doing his thing with the bouncing. They would use a tracking tape as a guide for the vocal overdubs. Then, the guys could go home while George combined the overdubs with the bounced instruments.
And then there are issues like lag time from the playback head to the record head, studers getting speeded up from their original speed, etc.
There are a couple of cool books on this. All You Need Is Ears by George is pretty cool. I can't remember the names of the other books.