Dreaded Buzz/Hum - Need Help (1 Viewer)

[ClydeW]

Hi everyone. I know buzz/hum probs have been asked before but my problem has been ongoing and I can't seem to find a way to fix it. I purchased an Onkyo HT-S660 system a little over a year ago. A few months ago I went and bought a red/white audio RCA cable and a small RCA red/white to headphone plug adapter to hook up my computer to the receiver for playing games, movies, music, and etc.

After hooking it up I noticed that it made a buzz/hum that made listening to anything through my computer a hassle - only at low volumes could I stand the buzzing. I tried to isolate the problem with my computer by taking it apart and experimenting. I went so far as to build a makeshift computer to see if it was the case or motherboard that was causing some problems (it's an old computer).

Turns out it was the power supply touching the sides of the case. Then I found out my monitor was causing the buzzing as well...then the fridge and microwave when in use...then the new mixer I bought a few days ago for my turntables. Hooking up my turntables or cd player straight to the receiver doesn't create the buzz and my cable box and game systems don't seem to be a problem either. I went to Lowe's and got a 3 prong circuit analyzer and it found an open ground in an outlet in my room...could this be the problem or part of it? It seems everything is sounding great unless I hook my computer or mixer up to my receiver and the buzz starts up again. If anyone has any ideas whatsoever on how to fix this I'd really appreciate it.

So far I've tried:

monster power strip
hooking up computer in other rooms via long extension cord
same as above with receiver
same as above with mixer/turntables
rebuilding computer
moving around speakers


My Room Setup:

-outlet #1-

onkyo ht-r500 receiver

power strip
-ps2
-xbox
-dreamcast
-cable box
-sylvania 20" flat screen
-subwoofer

-outlet #2-

extension cord
-2 technics 1210 mk5 turntables
-tascam xs-8 mixer

power strip
-400mhz pII computer
-20" flatscreen monitor
-phone
-cable modem

-outlet #3-

open ground...

 

[Stephen Cook]

Try Pluging the two power strips into the the outlets, then plugging every thing else into the two power strips . . . I have found that having it all plugged into the same outlets has helped
Stephen

 

[Cary_H]

Can you give us some more info with regard to how you're connecting the two?
Where from on your PC and into what on your receiver?
Has your RCA patch cord got 2 plugs on each end?
What purpose does the RCA to headphone adapter serve?
Two RCA plugs into a female headphone jack?

 

[ClydeW]

Stephen - For months I have put up with this buzz...but I will suffer no more. Your idea worked! Finally I have clear sound undisturbed by that buzz. Only problem now is moving everything around to accomodate moving my receiver to the opposite side of the room. Thanks again!

Cary - Receiver--->RCA--->female rca to headphone plug--->sound card is currently the way I hook up my comp to my receiver, however, I'll be upgrading to s/pdif later on.

 

[JasonRobinette]

I've also tried many variations on this theme, and get a loud buzz both on the computer and the TV.

I've tried the reverse (putting the sound from my console video game into my computer to use its speakers) and get the same buzz. It's loud when I use a female RCA adapter into a headphone plug then into my sound card's input (SB2 Audigy Platinum) and slightly less if I use the RCA inputs on the front console...

But the buzzing is unbearable.

I've all but given up, but I thought this site might be able to help!

J

 

[Patrick Sun]

It's usually a 60Hz hum that you are hearing if the power outlet you have is improperly grounded, causing a ground loop. Getting the outlet fixed, properly grounded, is the best way to fix the problem, or buy a ground loop isolator (kind of pricey), or using only 2-prong electrical connectors/adapters on the outlet (which unfortunately bypasses ground protection when spikes may occur).

If you do a search on 'ground loop' in either the DIY or speakers area, you'll come up with threads on the same topic, and possible solutions.

 

[Steve Berger]

If you're only connecting audio from the PC (not video) then the easiest solution is to add an audio isolation transformer. The can be found with most good AUTOMOTIVE accessory selections and run $10 - $15 and do a great job (a ground loop on a 300 watt+ booster amp would be catastrophic). Anytime you're connecting GROUNDED devices from different physical locations together you WILL get ground loops and you will have to isolate the offending device(s). Audio and antennas are easy to do since isolators are readily available for RCA cables and coax. Video/S-Video is another story however since I haven't found any cheap isolators ($75 - $100 each and a 2 are needed).