I've had had both for many years, the 707 bought new and the REF50 used.
The REF50 has been in my closet for over a 15 years. I decided to dust off the REF50 and
tried hooking up a ROTEL RMB 971 to it. One channel did not work, I tried many combinations.
I am positive I am hooking it up the ZA AUDIO OUT (pre-outs) F/L. I get mixed results. Lots of feedback hissing etc, poor sound.
I hooked it up to the 707 and same thing, only one channel worked and not that loud, flipped the cables around and the symptom
switched. I looked over the diagram over and over and pretty sure the F/L pre-outs are the ones I am hooking it up to. I decided to buy
a Emotiva, thinking the Rotel AMP was toast. I got a 2 channel BASx300. SAME THING! darn
. I called Emotiva and advised me to hook
up a phone, laptop, tablet directly to the AMP.. Well that worked perfectly. I decided to the same thing with the Rotel and both channels worked.
After looking trying alot of troubleshooting I decided a factory reset on both the BK's to get the pre-outs to work. No luck
..
Anyways want to be able to hook up to my Emotiva some new ZU's I plan to get soon. Any help appreciated.