[Wayne A. Pflughaupt]

Bob was referring to leaving no connection for Pin 1, like you have already done.

What are you using for the BFD’s output? I’d suggest a XLR/RCA cable like you have for the input. Don’t know if it’ll make a difference, but it can’t hurt.

Failing that, I’d suggest getting back to the basics: Disconnect all source components from the system, and then re-connect them one at a time. Typically the offending piece is a cable box or satellite receiver.

Regards,
Wayne

 

[RonS1958]

I have no doubt that it is the BFD. My AVR is a Denon with unbalanced sub output to the BFD. I just tried an XLR to RCA like you suggested from BFD to subwoofer. Same hum. I happened to have one because I had gone to Guitar Center last week and bought a Direct Box PDI passive ground lifter. (I had to use the XLR in order to connect it to the BFD). I put it between the Denon and BFD and the hum disappeared. But it cut the output from the Denon to the BFD (hence the subwoofer) so much that I thought the connectors weren't working. It was only after I increased my output from the receiver to the BFD (subwoofer) from -1.5 to +8.5 that I heard the sub again. I was afraid it was mucking up my BFD filters I have set so I took it out and I plan on taking it back. I was thinking of trying the Hum X but guitar center didn't have one on hand and the girl suggested the direct box. Should I just go the hum x route and see if that works? Like I said it is not my cable or anything else causing the hum. It is solely the BFD. If I take the BFD out and go straight to the subwoofer there is no hum whatsoever on anything anywhere anytime. But I really like what the BFD does for the sound of my system and want to keep it going. I do appreciate your time.
Thanks again,
Ron

 

[RonS1958]

Wayne,
Well back to the basics didn't take long. I just unhooked my cable feed to the DVR and the hum went away. (I had just the BFD and subwoofer on.)
Went outside and looked into the box and the ground cable was not connected at the grounding block. Cable guy just did some work a couple of weeks ago. But after I hooked it back up the hum is still there just a whole lot less but still noticeable. I will read into the solutions for the cable feed.
Thanks,
Ron

 

[RonS1958]

I ordered the Jensen ISO-MAX VRD-1FF cable Isolator from cable Solutions on EBay on Sunday, got it today, hooked it up and pleased to say that the hum is gone. No discernible difference in sound at all.
I never understood that the root of the hum was because of the way that cable must be grounded. (I did test the cable ground and it was proper). I had always thought the problem was because of the AVR to BFD connections. I sure did learn a lot. Thank you so much for your help and getting me pointed in the right direction Wayne.
Ron

 

[andyr]

I'm a big believer in standing on the shoulders of giants.
In this case that means I would like to know what solution folks use for addressing The Hum.

Right now I'm using a cheater plug, but I would like to solve the problem the right way. I saw the links to Jensen and Ebtech stuff, but Jensen has a bunch of different products, and the Ebtech links are qualified with words like "possible."

So, what are you audio giants using to address The Hum?

Not living in the USofA, I have no idea what "the dreaded BFD hum" is!

Can you - or someone - explain for me?

Thanks,
Andy

 

[Wayne A. Pflughaupt]

60-cycle hum from a ground loop.

Regards,
Wayne

 

[andyr]

60-cycle hum from a ground loop.

Regards,
Wayne

Thanks for the prompt response, Wayne.

And I now understand that 'BFD' stands for 'Behringer Feedback Destroyer' - so presumably this particular component has an earthing problem?

Andy

 

[Wayne A. Pflughaupt]

It’s typically a problem with some people’s system, or their having a less-than-ideal electrical situation, not the unit itself.

Regards,
Wayne

 

[bjc]

In my experience it's the combination of consumer equipment with the Pro equipment that causes many of the noise issues especially with rca from the consumer equipment (Yamaha receiver) to xlr (BFD, pro amp, etc)...aka unbalanced to balanced connection!

 

[Andre]

I had a problem with ground loop and it came from the cable going into the set top box which was hooked to the receiver which had an outboard Crown amp that didn't like it. I added a Jensen Transformers VRD-1FF between the incoming cable and the set top box and the hum disappeared.