Kenny202 Posted September 29, 2020 Share Posted September 29, 2020 Hope ok to post here, don't really have a musicians area. Having a problem at home with ground noise from my amplifiers. We don't have flourescent lights. All of the guitars and all of the amps are doing it so not just a badly shielded guitar. Leads are good. I read somewhere you need to use 3 pin plugs but I wouldn't be surprised if there was even a proper main earth joint outside. Any of you guys found a way to overcome it here? I mean lets face it the power supply probably rubbish and unregulated. is there a power filter or something they use to reduce the hum? Link to comment Share on other sites More sharing options...
RichCor Posted September 29, 2020 Share Posted September 29, 2020 In some recording studios I've worked in we ran the house mains first through an Isolating Transformer to decouple it from Earth-Ground to avoid ground-loop noise, conditioned it by running in through some noise filters to eliminate AC hum, then made sure ALL INTERCONNECTED EQUIPMENT used only that AC power source. Having shielded cable helps. Mics should ideally use 3-pin XLR connections. But if your environment is already filled with EMI or RFI sources then you'll be fighting an uphill unwinnable battle trying to isolate it without compromising on 'the sound'. Link to comment Share on other sites More sharing options...
Kenny202 Posted September 29, 2020 Author Share Posted September 29, 2020 Its only the guitars. Don't use mics, but as you said and only occurred to me while writing this post I am probably only 2 or 3 meters away from the TV where I sit, and about 3 meters away from the computer screen. But by the hum reducing when you touch the strings doesn't that indicate a ground problem? Link to comment Share on other sites More sharing options...
DrDave Posted September 29, 2020 Share Posted September 29, 2020 Try reversing the plug in the wall socket. My old (late 60's) Fender amp has a 2-wire AC power cord along with a "ground switch" that I believe reverses the polarity of the AC power cord in order to reduce hum. This should work, provided that your house wiring isn't wonky - which is highly likely. 1 Link to comment Share on other sites More sharing options...
Kenny202 Posted September 29, 2020 Author Share Posted September 29, 2020 (edited) 1 minute ago, DrDave said: Try reversing the plug in the wall socket. My old (late 60's) Fender amp has a 2-wire AC power cord along with a "ground switch" that I believe reverses the polarity of the AC power cord in order to reduce hum. This should work, provided that your house wiring isn't wonky - which is highly likely. If anything I would say VERY likely. Wasn't as bad as the last house I had would get electric shocks off everything. There was no earthing at all Edited September 29, 2020 by Kenny202 Link to comment Share on other sites More sharing options...
RichCor Posted September 29, 2020 Share Posted September 29, 2020 7 minutes ago, Kenny202 said: I am probably only 2 or 3 meters away from the TV where I sit, and about 3 meters away from the computer screen. But by the hum reducing when you touch the strings doesn't that indicate a ground problem? Try unplugging BOTH and see if that help eliminate some of the hum issue. Amplifiers aren't picky about what they're amplifying. A google search for guitar hum when not touching strings will send you down the rabbit hole, but might e helpful. The first highlighted article covers some interesting points. Minimising Noise In Electric Guitar Rigs Sound on Sound | Guitar Technology | By Dave Lockwood | Published 2006 A friend eventually went to using a battery-powered Amp setup with short as possible patch cords because there were just too many issues to solve. Link to comment Share on other sites More sharing options...
Kenny202 Posted September 29, 2020 Author Share Posted September 29, 2020 8 minutes ago, RichCor said: Try unplugging BOTH and see if that help eliminate some of the hum issue. Amplifiers aren't picky about what they're amplifying. A google search for guitar hum when not touching strings will send you down the rabbit hole, but might e helpful. The first highlighted article covers some interesting points. Minimising Noise In Electric Guitar Rigs Sound on Sound | Guitar Technology | By Dave Lockwood | Published 2006 A friend eventually went to using a battery-powered Amp setup with short as possible patch cords because there were just too many issues to solve. Thanks so much for your effort mate. I'll ask another question. Apart from safety reasons is it absolutely necessary to have an earth connected to your amplifier? For eg will it definitely hum if no earth at the outlet or a 2 pin plug is used? or only some amps, or sometimes or will be a bit worse with no earth? Reason I ask is one amp I have, a solid state sort of PA / Keyboard amp I bought new here and it definitely only came with a 2 pin plug. Funnily enough though it is the only one that doesn't hum. The other 3 do. 2 are valve amps to so I guess they are more prone to hum Link to comment Share on other sites More sharing options...
Dumbastheycome Posted September 29, 2020 Share Posted September 29, 2020 13 minutes ago, Kenny202 said: Thanks so much for your effort mate. I'll ask another question. Apart from safety reasons is it absolutely necessary to have an earth connected to your amplifier? For eg will it definitely hum if no earth at the outlet or a 2 pin plug is used? or only some amps, or sometimes or will be a bit worse with no earth? Reason I ask is one amp I have, a solid state sort of PA / Keyboard amp I bought new here and it definitely only came with a 2 pin plug. Funnily enough though it is the only one that doesn't hum. The other 3 do. 2 are valve amps to so I guess they are more prone to hum Is it possible that your mains power supply is "under voltage" ? Noting that you say it is the valve amps that hum suggest that because valve amps are trimmed output while solid state are power on output demand. Link to comment Share on other sites More sharing options...
Kenny202 Posted September 29, 2020 Author Share Posted September 29, 2020 13 minutes ago, Dumbastheycome said: Is it possible that your mains power supply is "under voltage" ? Noting that you say it is the valve amps that hum suggest that because valve amps are trimmed output while solid state are power on output demand. No, its not tube hum. I have 2 tube amps and a solid state bass amp and they are pretty much the same Link to comment Share on other sites More sharing options...
Yellowtail Posted September 29, 2020 Share Posted September 29, 2020 You might ask the mods to move it to the electric forum. If you're in Bangkok, the quality of the power is good. It might be cr*p in your building in the greater Bangkok area is fine. Link to comment Share on other sites More sharing options...
Kenny202 Posted September 29, 2020 Author Share Posted September 29, 2020 Just now, Yellowtail said: You might ask the mods to move it to the electric forum. If you're in Bangkok, the quality of the power is good. It might be cr*p in your building in the greater Bangkok area is fine. It is a guitar player specific question and I don't live on Bangkok. I have asked the question in a different way re home earthing in the electrical forum. Link to comment Share on other sites More sharing options...
cjinchiangrai Posted September 29, 2020 Share Posted September 29, 2020 Humbucker pickups? Single coils always buzz some. Link to comment Share on other sites More sharing options...
Kenny202 Posted September 29, 2020 Author Share Posted September 29, 2020 1 minute ago, cjinchiangrai said: Humbucker pickups? Single coils always buzz some. Got both HB and single coil and both pretty much the same. Its just a bit more than normal buzz Link to comment Share on other sites More sharing options...
Rookiescot Posted September 29, 2020 Share Posted September 29, 2020 Try un plugin your wifi, TV and anything else which will emit radio waves. Link to comment Share on other sites More sharing options...
pookondee Posted September 29, 2020 Share Posted September 29, 2020 47 minutes ago, Rookiescot said: Try un plugin your wifi, TV and anything else which will emit radio waves. Its true. Strange enough, i found it to be the fridge, in one place i lived. It would mess with my old tuner also as the tuner in the open mode would always be stuck around G or Gflat. Of course, I finally realised what was going on when the hum would suddenly stop and realised that coincided with the fridge clicking out. Link to comment Share on other sites More sharing options...
Crossy Posted September 30, 2020 Share Posted September 30, 2020 It would seem our OP has solved his hum problem ???? Link to comment Share on other sites More sharing options...
Kenny202 Posted September 30, 2020 Author Share Posted September 30, 2020 Yes, good as gold now. Changed all my plugs over to 3 pin. It appears the home earthing is good. By the way, I was always having trouble with the multi outlet power boards here. Even the expensive ones. What I do now if cut the lead off the broken one and go to local electrical store and can just buy the outlet board itself, no cord for about 100 baht. The ones I get a much more heavy duty, no switches etc to break and seem to last forever. Really good strong plug connections. Will accept different plug configurations. One in the photo only has one 3 pin outlet but can buy with 2 or 3. Just attach the old cable to it and good to go. I think they might be even made for tradies. The fancy 300 baht ones you buy switches always seem to fail, plug connections really loose, particularly if you have a charger or something heavier plugged in. Link to comment Share on other sites More sharing options...
Kenny202 Posted October 1, 2020 Author Share Posted October 1, 2020 9 hours ago, Rou222 said: I should try this as well, cause I'm done hearing the radio while the amp is on Thanks for the thread! Buzz instantly went away. Just make sure your power board has a 3 wire cable / 3 pin plug and your house is actually earthed. I have had other homes here had 2 pin and earth sockets but the earth wires in the home weren't actually attached to an earth outside. Funnily enough there was an earth rod installed specifically for the shower heater.....And a live power outlet mounted under the arm of the shower head.....I shirt you not! I guess someone liked to dry their hair in the shower lol Link to comment Share on other sites More sharing options...
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