To use an old receiver as an external amp to run 9.2 speakers you just need to connect a red white RCA cable from ext amp out on the back of your Onkyo TX-NR818, to the CD in or Multichannel Input on the back of your other receiver. It is best to use the Multi-channel input on the back of your other receiver if you have one, as this input will not apply any additional sound processing to the input. If you don't have a multichannel input then the CD input will work fine. Just select the straight decode sound processing mode for best results. You will then need to set the volume to 0/reference level. Now connect either your front high or front wide speakers to your receiver. Then go into the setup menu on your TX-NR818, and under speaker settings go down to Pre-out to external Amp and change the setting to either front high, front wide, or surround back, depending on what speakers you have connected to the 2nd receiver. I use my second receiver to power the Front Wide speakers, as this leaves the Front Wide/Zone 2 speaker terminals on the back of the TX-NR818 available for me to connect my zone 2 speakers to. Keep in mind though that you can't have the external amp pre-out, and the powered zone 2 settings both enabled at the same time. So if you want to use an external amp for 9.2 playback, and have zone 2 speakers you will have to switch the settings back and forth in the speaker settings menu depending on which you want to use at the moment. I created 2 macros on my remote to quickly switch the settings back and forth for me with a single button press, so this limitation doesn't slow me down too much.
Last edited by ComponentActual; 06-30-2014 at 02:10 PM.