Just in case some specific aren't covered in the FAQ...

Pre-amp to pre-amp is fine as long as you're not boosting with both of them. One of them will be kept flat and you can make your adjustments on the other (the one right before the power amps). In my case, I keep all empeg levels flat and the volume locked at 0db. My head unit then has a sensetivity adjustment for AUX-in which I set to "low" - the empeg outputs at a decent voltage.

You may be able to the the TV connections on your SONY. Can you switch to them even without a TV plugged into the bus connector? If so then you won't have a problem testing. If not, then you may need some kind of adapter to fool the head unit into thinking some supported device is connected (so it allows you to switch to that input stage). There already a thread going about a SONY head unit with this requirement. If there's no sensetivity adjustment (likely) then it will be tuned to a specific voltage range - such as 0-1v or 0-2v. You may need to set the empeg's volume below 0db to avoid clipping the signal on the SONY.

Bruno