Jump to content

Guitar player question....ground hum


Recommended Posts

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 post
Share on other sites

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 post
Share on other sites

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 post
Share on other sites

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.

  • Like 1
Link to post
Share on other sites
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 by Kenny202
Link to post
Share on other sites
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 post
Share on other sites
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 post
Share on other sites
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 post
Share on other sites
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 post
Share on other sites

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 post
Share on other sites
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 post
Share on other sites
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 post
Share on other sites
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 post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...