Try your amp and guitar in someone else's house. If you still have the problem, try a different guitar, then a different amp. This should lead you to the buzzing and crackling problem.
Phillip from Wales asks:
“Hi, can you help, please. I got this Marshall MG10, and I’ve had this buzzing and crackling problem when I play the Strat. I sent it back to them and they listened to the sound recording I had of the buzzing and they said I had a loose earth connection or the cable I was using to connect the guitar was no good.
Do you have a diagram of how to check the earth connection; would be most grateful to you.”
Thanks for your email.
The main thing is: isolate the problem.
Your best bet is to try your amp and guitar in someone else’s house. If you still have the problem, try a different guitar, then a different amp. This should tell you where the buzzing and crackling problem is.
If that doesn’t help try the cable, I had them cause static in the past; they do go bad. Any type of motor will cause noise — washers dryers, swimming pool pumps, etc. Fluorescent lights and any lights with dimmers on them will cause noise. My girlfriend’s makeup mirror is awful. Transformers on the power lines will cause noise. Most of these will cause an intermittent noise though and you will notice it coming and going.
Try using different outlets sometimes things make noise that shouldn’t. Take the amp to someone else’s house. Try different guitars.
If you are using pedals sometimes they bring in noise.
If you still can’t isolate it, check the wiring on your guitar against our Strat Wiring Diagrams. Reversed wires on the output jack could cause noise that should be going to ground to go to the amp instead.
Regarding how to check your earth connection: If you have a “Circuit Tester” and you really know what you are doing, you can use something like GFCI Receptacle Tester Klein Tools RT210, or a “Voltmeter/Multimeter,” something like a M830 Digital Multimeter. If you do not have a serious comfort level with electricity, we’d highly recommend you have a professional electrician do this for you.
Good luck and let us know how you make out.