B&K AVR707/B&K REF50 S2 to external AMP issue.

[selvestre]

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.

 

[lovinthehd]

So the pre-outs on both avrs yield same results? That's very odd unless you have bad cables, did you swap for another pair? Per the manual for your 707 pictured those are indeed the pre-outs. Do the speakers work fine on the speaker terminals of each unit?

 

[selvestre]

Not exactly the same results.. on the 707 only one channel works but the sound is definitely weak. When I swap positions the exact opposite happens. On the REF50.. when I turn on the amp, a pop happens, when I turn on the
amp a very load feedback comes out of both speakers. I saw a XLR/RCA switch.. I made sure it was on the off position. I can plug the speakers back to the 707 and hook up any source and all is good. Both amps work fine and the Emotiva sounds amazing with an ipad hooked up directly to the INPUTS. I had quite a few cables hooked up to my 707, 6 to the Audio Outs to my Oppo, I unplugged them all... going to undo them tomorrow and see what happens. I gave up my Marantaz AVR last week, wish I still had it so I can test. In the end I want to be able to use the Emotiva to the 707 to power up some floor standing. A direct source to the amps sounds really nice, right now a 25 dollar Amazon Echo... Was hoping someone had some experience with B&K's and know some quirks about them. The manual is soooo long, but the part to hook up external amps is straight forward. I've done this before on other AVR's.

 

[selvestre]

The 707 the speaker terminal is fine. The REF50 is a pre-amp... Both Emotiva and Rotel amps work perfectly from my iphone witha cable to the inputs. Emotiva told me how to that..

 

[lovinthehd]

How about the cables?

 

[selvestre]

The cables.. tried many Interconnects. Tributaries.. Audioquest interconnects and speaker (various)... New Blue Jeans cable. both interconnects and speaker cable. In the middle of undoing the biwiring config to my speaker (total waste) to see if by chance that is the cause.. atm my echo direct to the Emotiva is working out.. but that cant be kool for long. I found an contact at BK who support legacy devices. Maybe they've seen this.

 

[lovinthehd]

So cables are ruled out. Coincidence they both have issues simultaneously in the B&K units. Had the 707 been in regular use just without external amp? Curious why did you suspect the Rotel amp had an issue rather than the B&K....was it also unused for a while? Possibly something as simple as a solder issue, hard to know. Good luck!