I have an issue where the buzz through my amp is horrendous when turned up. It is worse through my Les Paul than strat and unbearable when I use pedals. I have tried feeding my rig through a ups and a mains conditioner. Neither make a difference. I am thinking I have a ground issue with my mains supply which is a PME type combined neutral and earth. I have been told to check for voltage between neutral and earth and this measures at 0.04vac which seems inconsequential. I have tried different cables and pedals. I have tried the amp elsewhere and there seems to be no significant buzz. I am considering an earth spike connected to earth on the socket I use for my rig. Any thoughts appreciated
Marshall 2061x, Les Paul Greg Martin reissue and Fender custom shop strat.
Comments
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Elsewhere in the same room or building? On a different ring in the mains?
Nomad
Nobody loves me but my mother... and she could be jivin' too...
I would not normally suggest this but since you have checked the neutral to earth voltage (where?) I don't think you are the type to kill yourself, so.
Check the resistance from a 13A outlet earth pin to a KNOWN good earth. A cold water pipe as it comes from the road is best. The idea is to make sure your mains circuits are actually earthed. Best to have a resistance less than 1 Ohm but since this is hard to measure accurately on most DMMs a bit more won't hurt (subtract out any test cabling) .
If you are earthed ok then you might be in a "field" from a sub station or overhead HT?
Once in a while I see threads on other forums about hum and nothing seems to fix it.
DO NOT play around connecting random earth spikes into the Company supply!
Dave.
Mains water pipe is plastic unfortunately so I would have to make my own earth as everything else in the house is bonded to the combined earth and neutral supplying the house. As you have guessed I have some experience with voltage testing etc. I removed a socket from the wall to measure between Earth and neutral and could hammer an earth spike in to the ground and measure resistance to the live on the socket upplying the amp. Would this be a suitable earth?
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Yes.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Try turning the amp on its side.
Dave.
I wasn't joking! This puts the transformer radiation into a different plane and could well null out the hum.
Anyone who has built a valve amp from scratch will understand the process.
Dave.