If I'm getting this right, you are trying to connect the speakers to the preamp (C-26)?
If so, your second explanation is what you should be doing. Connect the speakers to the 7100 and then connect the C-26 to the 7100. The C-26 is your volume control and you also connect your sources to it.
If so, your second explanation is what you should be doing. Connect the speakers to the 7100 and then connect the C-26 to the 7100. The C-26 is your volume control and you also connect your sources to it.