OK, so I moved into a new house a few months ago. Once the weather turned cold, I noticed that my previously dead-quiet TransFex Pro 212s amp, DigiTech RP500 effects processor, and Music Man Axis guitar setup got VERY noisy, of the 60 Hz variety. My “studio” (if you want to call it that) is a carpeted room on the third floor, and all receptacles are grounded.
The first thing I did was to try the RP500 processor by itself, with headphones plugged in. It turns out it doesn’t matter what outlet, or more strangely, what CIRCUIT I plug it into. ANY receptacle on the second or third floor that I plug my guitar into causes buzzing.
Next I tried the RP500 processor with different GUITARS, and got the same result.
So next, I purchased a $100 “isolation transformer” to plug my amp/ processor into, on the advice that it could solve this type of problem when everything else has failed. Unfortunately, the isolation transformer also failed to correct the problem, again, no matter WHERE I plugged it in.
One thing I did notice is that putting a finger on the metal sleeve of my guitar cable pin causes the buzz to basically stop. Obviously, though, I am unable to do this while the cable is in the guitar, and the buzzing returns.
Has anyone ever encountered anything like this? I DID recently notice that it is a 20 amp circuit, but all three receptacles are of the 15 amp variety. Could that be causing the problem?
Wireless router and cordless phone is connected on this circuit, but I have removed them from the room, and the buzzing hasn’t stopped. I’ll try what you suggested. Thanks!
Sounds like a possible ground loop. I have experienced it with my equipment at times. When the cable is plugged into your guitar, does the humming stop when you touch the bridge or strings?
Thanks Wendell. No, that doesn’t stop it. Here’s the weird part: the higher in the air I hold the cable, the louder the buzz gets. But, I tried turning off the light and ceiling fan, and the buzz still existed. Also, if I bring the cable closer to various other power sources and wireless devices, it makes the buzz worse. At one point, I was using the cable in this way as a tester, but before long, I had everything unplugged, and still had a buzzing problem.
I know this is a long shot, but could this be a humidity issue?
Ok Mark, I am a sound tec, and I have seen many similar issues. Usually, the fastest way to remove a buzzing, (or a hum in a main PA system) is to Ground lift the plug. Sometimes the ground is “noisy”, being basically a big antenna, which you are plugging into an amp. In the system that I run, there are days that I can hear the radio through the monitors. ( im serious) In some wild weird cases, you have to ground lift EVERYTHING plugged in, but try the cheep shot first. I know, I know, everyone says … no ground no good, but it wont hurt anything to try.
Do what he said, lift the ground. Try a 3 to 2 prong adapter on your amp.
(The buzz sounds like it could be a radio wave picked up by your guitar cord, or even the house wiring can act as a huge antenna)
Thanks John. I just tried that, to no avail. There seems to be some kind of EMI that is affecting my amp. If that is the case, changing the outlets to 20 amp GFI one wouldn’t help with that, would it. I’m almost sure the ones there now are 15 amp outlets.
No, the amp will always draw the exact same current regardless of changes to the supply. I’d take it to a friend’s place across town and see if that helps.
If it still buzzes in that location, I’d suspect a loose or faulty capacitor in the amp.
Since the isolation transformer didn’t help, you can totally eliminate the voltage SOURCE. Since you have no foreign connections (phone, catv, lan) you can eliminate ground loops and the like between the grounds of these various systems. You say you tried pluggin up all your 3-prong equipment without a ground pin (using 3-prong adapters), so the so-called “noisy ground” is out. You’re down to EMI or RFI, in my estimation. You have any dimmer switches nearby? You have any compact fluorescent lamps nearby?
Have you tried switching off every single circuit in the panel except the one you have your crap plugged into? If that helps, switch them back on one by one and see if you can get an offensive “leaky” circuit or circuits pinned down.
Thanks, Marc. I did try shutting off all the circuits once, and no luck. EMI and RFI are bad news, if that’s the case. How do I fix THAT?
Here’s something that might interest/ perplex you: the isolation transformer ITSELF started audibly humming AND physically vibrating when plugged into that outlet. Does that tell you anything?
TODAY, the weather turned from freezing (20-30 degrees F), to just ABOVE freezing and rainy. When I went upstairs to use the guitar, there was no buzzing. I played for awhile, then rain some errands, and when I returned, so had the buzzing.
On a whim, I asked my wife to pour some water on the grounding rod, and 10 seconds later, the buzzing stopped again.
I have NO idea what the length of my grounding rod is, but is 8 ft. the current standard? I suspect that mine is quite a bit less than that, since I can actually wiggle it around in its hole.
Just a thought did you check the neutral for voltage? it may be what is called stray voltage coming from the street. it sometimes happens on high rise bldg s.
Well, I am going to wait until the buzzing comes back, and then try pouring more water on the grounding rod. I am wondering if the earth AROUND the rod has eroded to the point that there is a “sleeve” of air all the way around it.
Again, is 8 ft. the standard length for a grounding rod? Thats all ANY of the area home improvement stores carry. Suppose a grounding rod change is in order, and that it might fix my problem?
