Hooking everything up for the first time

Sorry Rev, but you cannot hook those two units together. The Onyko NR515 does not have a set of pre-outs in order to use it strictly as a pre-pro. You are stuck with the Onkyo's internal amps. If it did have pre-outs, you would simply use RCA Audio Interconnects and would need 5 of them.

You will need an AVR that has pre-outs if you are intend on using the Emotiva in your system. These are usually the mid to high range models in manufacturers line-uos. Find the cheapest one you can that has a full set of pre-outs (not just subwoofer) that meets your decoding and room correction needs. Do not concern yourself about the AVR's power output - you won't need it. Good luck.

Your welcome Rev. Yes, you are right about no reasonably priced pre-pros. When you think it about it, they are basically AVR's without internal amps. They should be cheaper, right. NOT! Kind of makes you wonder how much it actually costs the manufacturer to throw in built-in amps???

The talk on internet forums about any AVR will do is correct except for one key feature - any AVR with PRE-OUTS! About the cheapest current model I can think of is the Yamaha RXV 773. They go about $800 usd. You might want to try the used market. Just make sure it is a newer model that has HDMI and will decode the new lossless audio formats. Prior to these lossless formats, it seemed most AVR's, even the entry level models, had pre-outs. Now this feature seems to be found on the $800 models and up. Things change. Good luck with your problem.