So, umm…wow.
I’m amazed. But no one in this thread has a clue how to do this…either that or they still don’t understand the OP’s question.
Now…for what you really want. How would I route that. There are 2 things I’d try: something free, and something dumb.
First, the free one. Plug the iPod into the DJM-800’s return (for the effects loop). Set the effects section to channel “1” and “send/rtn”, turn the level/depth all the way to the right and turn it on. That should send the iPod signal out to the mixer’s master output regardless of what else is happening while killing channel 1’s output to the master by taking the post-fader signal from channel 1 and send it out the effects send.
So…plug your turntable or whatever you’re scratching with into the input for channel 1 and set the mixer up however you want for scratching (with regard to faders, CF, etc.). Now here’s where I’m not sure it’s going to work…if the loop is post-fader, it’s fine. Take the fx send (which is capturing the signal coming out of channel 1) and use a cable to send it to channel 2 (or 3, or 4…whatever), set it as line level, turn the volume all the way down on that channel (maybe put a piece of tape in the way just in case), and hit cue for that channel.
If it works the way I think it does, you’re cuing the post-fader signal from channel 1 (your scratching), and killing its master output…at the same time, you’re sending the iPod straight to the master output.
I think that does everything you want…the only thing I’m not sure about is whether the DJM-800’s effects loop is post-fader, because I’ve never really paid attention to its effects when I’ve mixed on it.
And the dumb idea…buy a small PA mixer. Plug the iPod and the DJM-800 into it. Cue the DJM-800’s master signal and cut it’s volume on the PA mixer…blah blah blah…I’m sure this makes sense. The Behringer Xenyx mixers are actually really good at this. Their mic pres are noisy, but the line-level path sounds okay to my ears. And the one that’s best suited for doing what you want costs like $40.
Also, I didn’t read much of page 2 because I got pissed off at people…if you can just kill the master out on the mixer, there’s a cue button on the master channel between the pan control and the mono/stereo switch…might want to look into what that does.