That is correct. But you can use the pre amp box between any two points. Want to make your effects return to your console sound better, run the output of your effects to a mic pre amp then into the line level in on your mixer. In the case of a Tube mic pre, you get all the color and sizzle a tube circuit will give you.
So, usually I run my mixer outputs to
an ART Dual MP, then to a ART Dual Levelar, then to the DAT player. I will usually start up the mix before doing this, but when I start hitting the wall the tube gear cleans everything up and reveals so much about the mix that I was missing before. I good pre amp will do that, reveal more accurately what the source signal really sounds like. Then you can make better informed decisions concerning your mix.
Now for tracking, you would run the source signal (keys, vocal mic etc....) to the ART, then directly to the tape deck input bypassing the mixer altogether going to tape. Even when you run into the line input of most mixers you are still running through the pre amp. If the mixer is higher quality, it will have dedicated tape returns. Even these use an OP Amp, which will to a certain extent color the sound. So while tracking, it is good to avoid the mixer for going to tape if you are using outboard preamps. Only use the mixer for monitoring the track.
Ed