Home theater bypass

I have a Mac C48 preamp that only goes into bypass mode by a 12v trigger from a processor. I have been working around this as my Oppo 105 that I use as a processor has no 12v trigger.

Another idea would be to get one of those 12V wall wart DC power adapters, chop the end and solder it into a 1/8" male mono plug. Use that as the 12V trigger for C48 and then just plug it in when you want to trigger the C48 into bypass mode.

So now I am about to set up my new 205 which has a trigger to put the C48 in bypass, but what if I just want to play a CD and not HT, how do i control that, if every time I turn on the 205, the C48 goes into bypass.