Basses hum @ home only

[WillieJ]

I searched the thread for this, and couldn't find any reference, so I'm sorry if this is addressed elsewhere.

My basses are humming away ... in my house. Maybe they're just happy to be home ... but I'm not sure what to do and hoping someone has an idea.

When I play at home,my basses hum. Touch the strings, or bridge = silence. Noise stops. I thought it was the basses...but apparently no. Take the same basses, cable, amp to the house where we practice...no hum. Take either of my basses to any venue...no hum. Go home and plug in...hum.

I checked the outlets & they appear to be grounded. Could I have an issue at the mains? Has anyone heard of anything like this before?

 

[mjolnir]

There's probably a ground loop somewhere. It may not be at the outlets, but it's there.

 

[McGroovin']

Aye, my house has those old 2 prong outlets. My basses hum away without a ground.

 

[Jay Corwin]

Sometimes people put the three prongers in even without a ground wire connection. I have an old house that doesn't have a ground wire run to the receptacles. The originals were all the two prong variety. This may sound like a dumb question, but how did oyu come to the conclusion that they are grounded? I've done quite a bit of house wiring, so if you need - PM me.

 

[FLWing]

"...I checked the outlets & they appear to be grounded".

If you're getting a hum then somewhere you have an issue with a ground loop. Not necessarily a lack of ground, but you are probably plugging your equipment into two different circuits which is inducing an imbalance in ground. This site can explain better than I: http://www.epanorama.net/documents/groundloop/

Although the best solution is to ensure all your gear is connected to the same circuit (not multiple circuits), the cheapest route is to get a ground loop eliminator - I carry an EBTECH HUM X with my stuff to use just in case...cost less than $50 thru http://www.sweetwater.com/store/detail/HumX/

 

[Cryhavok]

As mentioned, could be the grounds. Could also be from some relatively large EM fields. You dont happen to be around several computers/large electrical devices, do you? You could always build a sweet Faraday cage to play in

 

[EBodious]

As mentioned, could be the grounds. Could also be from some relatively large EM fields. You dont happen to be around several computers/large electrical devices, do you? You could always build a sweet Faraday cage to play in

yes, don't discount shielding. i had (have) the same problem, only in my case it was my new-to-me bass and it happened in my home and the home that the band practices in. i concluded it was the bass. i posted a lot, here, and troubleshot a lot to no avail. it wasn't happening in music stores and other commercial spots, though. very confusing and frustrating. a well respected amp tech concluded it was external and environmental and shielding related. he said by touching a metal part of the bass i was shielding the electronics with my body. i had thought it was grounding, but i found that when it was humming i could make it go away (or get louder) by changing where i stood or which direction i faced. the "touching metal" effect made me think it was grounding, but that wouldn't change with my physical position.

also, it only happens with my active bass in active mode. passive = no hum.

i gotta say, since learning what the problem was (and gaining a "sense" of control) it doesn't bother me as much as when the bass was new and something was wrong with it!! go figure.

oh and btw, i have 3 prong plugs on a very old house. it is "grounded" by the metal conduit. no much of a ground, but it sort of works!?!?!??!?!?!?

 

[thehangingmist]

when at hoe do you play right next to a crt monitor or a florescent light?

 

[McSpunckle]

Sometimes people put the three prongers in even without a ground wire connection. I have an old house that doesn't have a ground wire run to the receptacles. The originals were all the two prong variety. This may sound like a dumb question, but how did oyu come to the conclusion that they are grounded? I've done quite a bit of house wiring, so if you need - PM me.

Sorry, this is a bit off topic, but I do have the same problem as the original poster...

Since you've done some wiring... what's the point of the ground wire anyways? They end up connected once they get to the main electric panel...

 

[Jay Corwin]

Sorry, this is a bit off topic, but I do have the same problem as the original poster...

Since you've done some wiring... what's the point of the ground wire anyways? They end up connected once they get to the main electric panel...

Well to get a bit techy on ya'll...

The purpose of the ground wire (3rd prong) is to allow a path for electricity to flow safely in the event that there is some sort of electrical failure on a device you are using (musical or otherwise). For example, if you have something short out that is connected to a grounded outlet, then the most that will happen is that a circuit breaker or fuse will pop (in most cases around the house).

 

[theshadow2001]

To me it would seem that it's not a ground loop issue. I'm thinking this because the hum is going away when he touches the strings. Essentially what he is doing is connecting his body to ground through the strings. His body then acts as a big old shield absorbing radio frequency interference and sending it to ground from his body through the strings then through his amp back to earth.

So something is emitting radio frequency interference in the room that your playing in. I suppose the shielding the electronics would be a good place to start reducing the hum.

I think and may be wrong, but if it was a ground loop issue the amp would make the noise with or without the bass plugged in.

 

[WillieJ]

Thanks for all the replies and suggestions.

I need to figure out quoting technique, but manual responses:
McGroovin and seventyyearsdown asked about grounding ... I have 3-prong ouilets, opened them up and tehre is copper ground wire, and it is firmly screwed onto the outlet. House is 1880's-era - hoping grounding is done right.

FLWing ... I'll check the link you offered and look into into ground loop.

Cryhavok - no EM fields, fluorescent lights, etc.

EBodious - both my axes are passive mode, so not sure the shielding issue would be the same. And if it were, sounds like no solution from your tech pal was offered.

Any other suggestions appreciated ... but will check into groundloop details. And will let ya'll know about future developments. Thanks again.

 

[theshadow2001]

Cryhavok - no EM fields, fluorescent lights, etc.

My old crappy PC speakers used to be able to pick up the washing machine in the next room. You never know where an EM source may come from.

Just an FYI

the button between to the right of the one that says quotes with quotation marks on it on the bottom right of everyone's post allows you to do multiple quotes. Just click on the posts you want to quote and then hit post reply and they'll appear in box where you write your posts.

 

[WillieJ]

My old crappy PC speakers used to be able to pick up the washing machine in the next room. You never know where an EM source may come from. .

Appreciate that insight. Reflecting on that, there could be some possibilities. If it does turn out to be shielding...is there anything to be done - other than simply turn a deaf ear to it?

 

[Cryhavok]

Appreciate that insight. Reflecting on that, there could be some possibilities. If it does turn out to be shielding...is there anything to be done - other than simply turn a deaf ear to it?

Are you looking to record, or are you just practicing and annoyed by it? If you're not recording, I'd just try to position yourself so its at a minimum, and ignore it the best you can.

Try moving to a different room in the house and see if it gets better there. Otherwise I'd say theres not a lot you can do about it, short of building up that Faraday cage

 

[theshadow2001]

Appreciate that insight. Reflecting on that, there could be some possibilities. If it does turn out to be shielding...is there anything to be done - other than simply turn a deaf ear to it?

Well if you find the source you can unplug it while you play. You could shield your electronics. Moving to a different room is another option. I'd try that first.

 

[EBodious]

dimmer switches on lights are a big noise source if they are not full on or off (anywhere in the house). my house isn't quite as old as yours, but the wiring is somewhat dubious. when it was converted to circut breakers 2/3 of the lines were put on one breaker! it doesn't pop, but a dimmer anywhere on that breaker effects all the other outlets. my experience with electricity (playing music as well as home repair) has led me to the conclusion that electricity is weird. and unpredictable. some believe that science has figured it out. i don't agree; it is still mysterious (IMHO).

does the hum change in volume when you turn your body back and forth? or walk a few steps in different directions? remember you have electric wires running around inside all your walls creating em fields. that would suggest its em interference.

if it is a shielding issue, the solution is posted as a sticky at the top of this forum. i haven't done it to my bass, but it hasn't been a problem at gigs or in the studio yet.

 

[spaz21387]

What kind of bass is it? Most fender jazz basses hum. The best thing you can do is shield the cavity where the pots are and even around the pickups if theres enough space. All music places sell copper shielding tape for like 10$. My jazz didn the same thing. It turns out that some of the problem was the bridge wasnt making a good connection to the bridge. I took a dremel and sanded off some of the chrome and it helped alot. It still hums alittle but not nearly as bad as before. So check your ground and get some copper shielding tape. Also try a different outlet in your house. My bass would pick up the radio using one outlet in my house. Why it did that I have no idea.

 

[WillieJ]

Problem solved.

Thanks for all the help and suggestions...but found different path to solution.

Chatting with Glenn at Bass Specialties yesterday (great shop in Bensalem outside Philly) he suggested using a 2-prong adapter on the 3-prong from amp. Buzz reduced about 90%. Guess what I have left is that typical, infamous J-Bass single pole hum. But its very low and bearable. Apparently the real problem is in the house...but this is much easier (and chaper) than calling out an electrician to re-do the house's grounding.

Thought folks might like to know how this turned out. Thanks again for everyone's help.

 

[EBodious]

Problem solved.

Thanks for all the help and suggestions...but found different path to solution.

Chatting with Glenn at Bass Specialties yesterday (great shop in Bensalem outside Philly) he suggested using a 2-prong adapter on the 3-prong from amp. Buzz reduced about 90%. Guess what I have left is that typical, infamous J-Bass single pole hum. But its very low and bearable. Apparently the real problem is in the house...but this is much easier (and chaper) than calling out an electrician to re-do the house's grounding.

Thought folks might like to know how this turned out. Thanks again for everyone's help.

you gotta be kidding?!?!?!!?

i assume you mean using the 2-prong without properly attaching it to the screw that holds the faceplate on the outlet (that would properly ground the three-prong plug to a two-prong outlet, but nobody ever does that).

i had a guy at a music store tell me my problem was that i had a "double ground." so it was cancelling itself out and that i should un-ground my amp by using a two-prong adaptor (improperly, just to remove the ground).


i thought he was crazy.


i tried it anyway.

it did not work for me. but i am happy to here it worked for you!!

live and learn, huh?!