Home theater bypass

I like the schematic but I have a question. The passive pre is the cj the amp is the Mac receiver than what is the CDP where does it connect on the cj. Please excuse all the questions but I am still learning and I don't want to blow anything up. Many thanks 

You connect the CDP to any line level (non-phono, let's say the "tuner") input on the CJ and the L/R preouts from the Onkyo to another line level (let's say the "ancillary") input also on the CJ.  When you want to listen to 2-channel you choose the "Tuner" input on the CJ and when you want to do surround through the Onkyo you switch the CJ input to "Ancillary" and adjust the volume on the CJ to the reference level that keeps the L/R speakers balanced with the center/surround speakers.  That's basically it.  Just to be clear, only the preouts from the CJ go to the Mac 275. 

https://www.computeraudiophile.com/uploads/monthly_2013_09/58cd96b7e0681_HomeTheaterBypass.JPG.02904...
In the schematic, CDP is a compact disc player (CD player), passive pre is the cj and amp is Mac 275 and receiver is Onkyo 805.

Maybe this schematic give you a better idea:
http://daveayers.com/Audio_Diagrams.htm

To operate ether system all units must be on ?

I tried it and the protection circuit tripped on the Mac 275 twice ?