Why do I get a horrible buzzing noise when I hook up a pair of RCA cables to my pre amp?

Question

I get this very loud buzzing (almost like feedback but at a lower pitch) from my stereo when I hook up another pair of RCA cables to my pre amp. Why is this?

I have a pre amp and an amp. I've had them five plus years and I've never had this problem. I have a CD player and an XM Radio hooked up to it without any problems. I'm trying to hook my Nintendo Wii up to the stereo, but I get the strange noise. I also get the noise when I hook up the TV. I've tried different RCA cables, but that doesn't change anything. I've tried different plugs in the back. I've tried switching to the CD player with the TV, the CD player will work fine and the TV will give the sound.

What's really weird is that I can hook up the RCA cable, I get the noise, I then turn the amp off and I still get the noise! How is this even possibile when I've turned the power off from the amp?

I just want to be able to run my Wii through my stereo! This shouldn't be that hard.

Based on some of the answers, it sounds like having a common ground is critical. I think they are all grounded to the same wire. There is one 'master' power cord that all of the electronics are feeding off of. I also have an electrical tester and I've confirmed that the outlet is indeed grounded.

Not sure if this is part of the problem, but the TV and the Wii are not grounded. (But the XM Radio and CD players are also not grounded, so I don't think this is the issue.)

Answer 1

Sounds to me that there is something wrong with your Wii or the Wii cable. Did you try an aftermarket version of your AV cable or use the crappy gray thing they give you?

The ultimate test would be to plug your audio wires directly into your amp, just make sure gain or level adjustment is low at first, then turn up when there should be sound.

Did you try the Wii on an alternate tv?

Answer 2

Sounds like it might be 60 Hz mains AC pickup (or 50 Hz if you're in a country that uses that for power distribution). If this is a steady, low-pitched buzz (though it can shake speakers so badly that it might have higher rattling overtones),
A few reasons you might get AC pickup:
o A bad ground connection: If your equipment has 3-prong cords, check that neither the cable is broken nor that the outlet is misconnected. Check that the neutral wire coming into your house is connected (just look at it from a distance fro something obviously broken and dangling. DO NOT try to measure it).
o A bad coax cable:if the braid is broken, it would pick up AC noise.
o A ground loop: One piece of equipment has a chassis that is "hot" relative to another. Try reversing line cord in outlet for just one device, if it is not a polarized or grounded plug.
o A broken connection in the amp to the shell (outside) of the RCA connector.
o A bad pole transformer: before they go up in smoke, a "pole pig" may cause lots of "static".
o A bad power-supply electrolytic capacitor. Not hard to fix, but requires some knowledge of electronics.

Answer 3

Hi. lets try the process of elimination.

(1) Turn all equipment off. Disconnect Pre-Amp. from Power Amp. Turn Power Amp. on and listen for hum/buz from the speaker .If there is no loud noise, then Power -Amp is ok.

(2) Remove all Interconnects (INPUTS) from Pre-Amp. Connect Pre-Amp. to Power Amp.(pre out main in) Turn Pre-Amp. and Power Amp. on. If you hear loud buzz/hum coming out of a speaker ,then Pre-Amp is the culprit.

(3) If the Pre-Amp passes the test ,then the next thing to do is to start connecting the other equipment one piece at a time to the Inputs of the Pre-Amp, until you find the one that is making the noise.

Lets know how you go.

Answer 4

Your problem may just a floating ground, try grounding all items in your system to a common ground! The other possibility is you have a open in your wiring system which is a little more complex to troubleshoot. P.S. If you try the common grounding and still have problems let me know we'll see if we can isolate further...

Answer 5

probably the cables. attempt diverse cables if achievable. I had the comparable subject and switching the cables fastened it. would additionally be the inputs on your television. I had a television that did that when and it replaced into through inputs being undesirable. So it truly is a pair particularly some issues.

Answer 6

I had that happen before and i bought a new pair of rca cable and it worked fine.