Please help me with this hummmmm

[hockeyman92]

I just received a HK AVR 310 that I bought off ebay. I have it hooked up to BIC DV62SI speakers and a sony sa-wm250 subwoofer. When everything is turned on and connected there is a humming noise that comes through my speakers. Once music is put on you cannot notice it until the volume is turned down all the way. Can someone tell me what would be causing this to happen? Is it the receiver, maybe a connection? I double checked the connections and nothing. The only thing is if I switch to a different mode it gets quieter, but then louder on certain ones? Let me knowif anyone can help or if you need more info.
Thanks,
Adam

 

[jaxvon]

Sounds like you might have a ground loop. Check out the troubleshooting tips in this article. If nothing in there seems to lead down the right track, checka-backa and we'll see what we can do.

 

[hockeyman92]

alrighty, i will check it out tomorrow...come to think of it I had this same problem in my car and I bought a ground loop islolator and it eventually just went away?

 

[Buckeyefan 1]

I just received a HK AVR 310 that I bought off ebay. I have it hooked up to BIC DV62SI speakers and a sony sa-wm250 subwoofer. When everything is turned on and connected there is a humming noise that comes through my speakers. Once music is put on you cannot notice it until the volume is turned down all the way. Can someone tell me what would be causing this to happen? Is it the receiver, maybe a connection? I double checked the connections and nothing. The only thing is if I switch to a different mode it gets quieter, but then louder on certain ones? Let me knowif anyone can help or if you need more info.
Thanks,
Adam

Try plugging your subwoofer's power cord (if it has a third prong ground) into a three prong to two prong adaptor. That will float the ground on the subwoofer and should eliminate the 60 cycle hum. It's a cheap .69 fix until you get your group loop isolator. Sometimes plugging a sub's power cord in an outlet on the same circuit as the cable box's power cord yields that terrible hum. Easy fix. If you disconnect the subwoofer altogether, do you still get the hum?

How does it sound? Did the receiver arrive in good shape? That was a heck of a deal on that unit if I remember correctly. Make sure the bare copper speaker wires don't touch each other at the rear of the receiver, or at the speaker terminals. Only splice as little as possible off your speaker wire when connecting it up - solder the ends just to make sure. Also keep the receiver ventilated. Just some basic tips to keep your unit running for a long long time (since there's no warranty).

 

[hockeyman92]

I am going to check all the connections right now...the hum was there before I connected the subwoofer. I got all of my equipment for $400, the receiver was 180 the speakers 120 and the sub 100. I am pretty pumped. The receiver looks beautiful, I love it cosmetically, and I am sure I can get rid of the hummm. Otherwise the speakers sound awesome. I am so pleased, thanks for the help!!

 

[hockeyman92]

Ok well I had it hooked up in the basement, but have now moved it up to my room...There is the single two prong power cord of the receiver in the wall and then two leads of wire, one to each speaker...I still get the hummm...Also when ever I turn the volume up, and there is no sound coming through, the humm gets louder...I read the ground loop thing and can't seem to find something that works...I dont know what to do!!!

 

[Buckeyefan 1]

Ok well I had it hooked up in the basement, but have now moved it up to my room...There is the single two prong power cord of the receiver in the wall and then two leads of wire, one to each speaker...I still get the hummm...Also when ever I turn the volume up, and there is no sound coming through, the humm gets louder...I read the ground loop thing and can't seem to find something that works...I dont know what to do!!!

Very odd. I wonder why it's two prong and not three. It sounds like the receiver floats its ground and probably should be grounded.

I would call HK Monday and ask them for advice. They have an outstanding customer service department.
If you would prefer to contact us by phone, and you live within the U.S., call 516-255-HKHK for Harman Kardon Customer Service.

 

[Josuah]

Floating ground can be dangerous. I wouldn't recommend doing that to try and fix your hum. I was able to reduce ground loop hum in my system by buying some 12awg copper wire from Home Depot, wire cutters/strippers, and those wire twisty connectors. Then connected the chassis of all my components (not the subwoofer) together at one of their screws, and then also into a ground prong hole on my power strip. You must use a screw because the paint on a chassis will prevent a connection to the copper.

 

[The_Maxx]

hey!!! I have the same problem!!!

Hi there i am a newbie here I will explain my problem PLEASE HELP!!!!!!


I have an old 135 WATT RCA Home Theatre/Hi-Fi Series Model ED-3600F which includes 2 surround speakers the center speaker and A B speakers (supposedly every speaker is 8 ohm) and also it has Dolby surround (the basic one, cuz this A/V receiver is old, hey! my uncle passed it to me!! what can I say!)

anyway, here is my prob.

I have connected to this A/V reciever:

*PC, to gain more audio experience when playing halo and also to hear my music as rear speakers (my front PC speakers are the VS 4121 Altec Lansing)

*DVD

*TV

*VCR

*CD

*Tuner

*TAPE


The thing is that when I connect my pc to the AV receiver and switch to the video 3 channel to hear it I hear a hummmmmm that is very annoying, and i want to get rid of it but I don't know how!!

I have done several tests like just connecting the computer to the receiver and the result is that it works perfect, but at the time that I also connect my tv audio channels or VCR audio cahnnels to the Stereo OR just connect the audio channels from the DVD to my AV receiver and the video cables directly to the TV it makes that damn hummmm thing.

I'm desperate and don't know how to fix this thing.


PLEASE GUYS HELP I have searched for help but no one around this city knows how to fix my issue. And i don't think that my receiver needs to be fixed, because it works perfectly.

 

[WndrBr3d]

Ok well I had it hooked up in the basement, but have now moved it up to my room...There is the single two prong power cord of the receiver in the wall and then two leads of wire, one to each speaker...I still get the hummm...Also when ever I turn the volume up, and there is no sound coming through, the humm gets louder...I read the ground loop thing and can't seem to find something that works...I dont know what to do!!!

I had this exact same problem.

http://forums.audioholics.com/forums/showthread.php?t=10420&highlight=hum

I took my AVR7300 to the shop and they found a screw loose in the transformer which was grounding it out, causing the hum.

Take it to an authorized repair shop and have them take a look at it (if it's under warranty).

 

[jaxvon]

If you have your PC connected to your receiver via the analog inputs, that is most likely the source of the hum. Computers are awash with RFI and EMI. If you can, use a digital output from your computer to the receiver.