guitar amp/ stereo speaker buzzing

[Lizzy's Power Play]

Hi everyone.
I have a residential customer with a small music studio in his front room. Approx. 3 weeks ago, all his guitar amps and stereo speakers started buzzing very loudly. It buzzes for a few moments, then goes away, then returns. It's happening on different circuits, multiple rooms with different amps and guitars.
Service is 3 years old, nothing is loose, grounding is fine. Trying to track it down, I turned off every breaker in the house, connected a receptacle directly to one breaker at the panel and ran an extension cord with ground to one of the amps. Still buzzed with nothing plugged into that cord except the amp. Power to the rest of the house was off. Are the guitar pick-ups picking up interference from something? Customer claims he hasn't bought anything new or changed anything to prompt the buzzing.
Any suggestions?

Thanks!!

 

[zbang]

Some guitars and guitar pickups will buzz for no other reason than someone is listening .

See if your client has a small battery-powered amp or can borrow one. If it buzzes with the battery amp and the house power off, move it around and try to locate that way. Have you tried a different guitar cord (or a different guitar)? A flaky cord will also buzz badly.

 

[templdl]

Hi everyone.
I have a residential customer with a small music studio in his front room. Approx. 3 weeks ago, all his guitar amps and stereo speakers started buzzing very loudly. It buzzes for a few moments, then goes away, then returns. It's happening on different circuits, multiple rooms with different amps and guitars.
Service is 3 years old, nothing is loose, grounding is fine. Trying to track it down, I turned off every breaker in the house, connected a receptacle directly to one breaker at the panel and ran an extension cord with ground to one of the amps. Still buzzed with nothing plugged into that cord except the amp. Power to the rest of the house was off. Are the guitar pick-ups picking up interference from something? Customer claims he hasn't bought anything new or changed anything to prompt the buzzing.
Any suggestions?

Thanks!!

I always make it a practice whenever possible to supply power for the components from the same line side of the panel. As such all of the line side feeds to the components will be zero volts sppart and no 240v. I have found there to be less trouble with noise. If there is noise on the live the you want to remove each branch circuit one at a time to see if you can get lucky enough to find the source of the noise.

 

[J.P.]

I have a small home studio and a decent collection of guitars and amps.

Usually a bad jack or cord will be the culprit.

You are saying that no matter which guitars is plugged into which amp, it buzzes, correct? I assume he has tried different cords or wireless units?

I typically run power conditioners at the top of each rack for many reasons, noise being one.

Guitar pick ups can pick up noise, BUT unless he has a bunch of cheap single coils the pick ups are usually well shielded and are pretty quiet.

Check the meter & main lug connections and see if maybe something new got installed in the neighborhood, you could have noise coming in over the powerline. Could be a loose connection or a problem at another residence or business. You might call the poco and ask them to check.

Big windstorm or accident 3 weeks ago maybe?

Stuff like this can be frustrating. Tempting to install a isolation power/ balancing transformer......They make them for just this purpose.

https://www.gearslutz.com/board/rem...rding/464809-power-isolation-transformer.html

 

[FullDuplex]

I turned off every breaker in the house, connected a receptacle directly to one breaker at the panel and ran an extension cord with ground to one of the amps. Still buzzed with nothing plugged into that cord except the amp. Power to the rest of the house was off. Are the guitar pick-ups picking up interference from something? Customer claims he hasn't bought anything new or changed anything to prompt the buzzing.

Ground problems are more apt to generate hum, a sharper buzz is more likely coming from a switching power supply, which could be in a neighbor's house. Switching supplies can add a tiny narrow spike or notch in the AC waveform. When you had everything else off, did you also try a second amp by itself, to be sure the source of the problem was not that amp?

 

[Dennis Alwon]

This stated 3 weeks ago and everything was fine before that. So I would look for what has changed.

Take the guitar and amp to another home and see if the issue is there. Is there a community water? Perhaps someone lost a neutral and is using the water linesthru the street as it's return path. To be honest I know nothing about guitars and amps

 

[junkhound]

Lizzy, do you have an oscilloscope or scopemeter?

Once you have tried swapping out components (amp, guitar, power, power off battery inverter (buzz will be different if powerline), etc.)
A scope almost mandatory to find the source of the buzz. You can buy a scope module on line for under $40 that uses a USB to plug into your laptop.

Look at the audio waveform, then look at the powerline waveform, then look at the waveform with just a big loop of wire hooked to the scope. See what has the same frequency, etc.

 

[ggunn]

Guitar pick ups can pick up noise, BUT unless he has a bunch of cheap single coils the pick ups are usually well shielded and are pretty quiet.

Single coil pickups are susceptible to RF noise no matter how expensive and well shielded they are.

 

[ggunn]

Hi everyone.
I have a residential customer with a small music studio in his front room. Approx. 3 weeks ago, all his guitar amps and stereo speakers started buzzing very loudly. It buzzes for a few moments, then goes away, then returns. It's happening on different circuits, multiple rooms with different amps and guitars.
Service is 3 years old, nothing is loose, grounding is fine. Trying to track it down, I turned off every breaker in the house, connected a receptacle directly to one breaker at the panel and ran an extension cord with ground to one of the amps. Still buzzed with nothing plugged into that cord except the amp. Power to the rest of the house was off. Are the guitar pick-ups picking up interference from something? Customer claims he hasn't bought anything new or changed anything to prompt the buzzing.
Any suggestions?

Thanks!!

I have a similar situation in my studio, though it's not as bad as what you describe and it's not intermittent. In my case the source of the noise is a set of MV lines that run parallel to the long axis of my house up on poles only about 20' away from my studio. Single coil pickups into high gain circuits howl like banshees unless you stand with the guitar perpendicular to the path of the conductors. Dynamic mics have the same problem but to a much lesser degree.

When your customer is holding a guitar and the amp is buzzing, if he turns 90 degrees does the buzzing get quieter/louder?