Bad Humming Sound - home wiring problem?

Dan Barracuda · #1 03-22-2018, 09:24 PM

Hey guys,

Today was a crazy day. I went to GC to pick up my amp (Egnater Tweaker!) this afternoon. Was soooo excited. Went home, and started hearing this odd humming sound. Really wasn’t sounding great. My friend (who works at GC) came over to check it out. He couldn’t figure out what it was, but he speculated that it might have to do with the wiring of my really old apartment. Went to GC to pick up a power conditioner (I think is the name) power strip (Furman). Went back home, and it didn’t fix the problem.. Then we drove to my rehearsal space with my new strat and amp. Plugged in, and it was totally fine. Sounded so amazing! So now I know that it’s not the amp or the strat. It must be something to do with my apartment. Does anyone have any experience with this issue?

Thanks!

Steve DeRosa · #2 03-22-2018, 09:50 PM

Fairly common with tube amps, in structures built before modern wiring codes - FYI that's why [1] humbucking pickups were developed, and [2] many older mid-/high-power amps (pre-1990) had polarity switches. Nothing to really worry about IME, and if it gets too annoying/uncontrollable (try turning the amp at different angles to your body to minimize the hum) find a three-to-two prong adapter with two equal-size blades and try reversing position in the wall socket until the hum is minimized...

endpin · #3 03-22-2018, 10:13 PM

You really haven't ruled out inductive coupling of hum directly into your guitar pickups.

If you see a a “null” in the hum as you rotate your GUITAR (aligning it in the fields within your house), then it is probably coming in through your pickups.

Alternately, short the amp input and see if the hum goes away.

clintj · #4 03-23-2018, 04:59 AM

Quote:

Originally Posted by Steve DeRosa

Fairly common with tube amps, in structures built before modern wiring codes - FYI that's why [1] humbucking pickups were developed, and [2] many older mid-/high-power amps (pre-1990) had polarity switches. Nothing to really worry about IME, and if it gets too annoying/uncontrollable (try turning the amp at different angles to your body to minimize the hum) find a three-to-two prong adapter with two equal-size blades and try reversing position in the wall socket until the hum is minimized...

No. No, no, no, no. Do NOT do this. That works on older amps because one leg of the wiring in the amp is referenced to ground through a death cap. Modern amps don't do this, and if an issue develops where the amp chassis becomes electrically live, it can cause serious injury or death because you have now defeated the safety ground - YOU are now the ground. You also defeat the amp maker's efforts to have the fuse first in the power wiring, which is also important for the safety of you and your amp.

Buy an outlet tester, they're $10 or less at Home Depot. Make sure you have a properly wired outlet, and if you don't, tell your landlord. Every guitarist should have one of these in their gig bag, IMO.

Again, don't risk your safety just to have a quiet amp.

paulp1960 · #5 03-23-2018, 05:47 AM

Yes it's a really bad idea to disconnect the earth connection from a valve amp.
It could save you or someone else's life.

Dan Barracuda · #6 03-23-2018, 10:49 AM

Thanks for the help and feedback guys. So the outlet tester should work?

MiG50 · #7 03-23-2018, 10:58 AM

Quote:

Originally Posted by Dan Barracuda

Thanks for the help and feedback guys. So the outlet tester should work?

An outlet tester will tell you if the wiring in your apartment is correct, i.e. Hot, Neutral, and Ground are all correctly wired (and the Ground is actually connected to something, which isn't always true in older houses). This can show you one possible source of hum, and it's a fairly cheap piece to purchase.

There could be something else causing interference in the power side of thing, like a large appliance (refrigerator, heating or AC unit, etc). There could also be some source of RFI which is inducing hum through the signal input (guitar, cable[s], pedals, etc).

At least the amp sounds clean in another location, so you can be pretty certain there's nothing internally wrong with the amp itself.

Song · #8 03-23-2018, 11:13 AM

Quote:

Originally Posted by MiG50

There could be something else causing interference in the power side of thing, like a large appliance (refrigerator, heating or AC unit, etc). There could also be some source of RFI which is inducing hum through the signal input (guitar, cable[s], pedals, etc).

and sometimes cellular devices cause noise with some tube amps...
Good luck!

Big Band Guitar · #9 03-23-2018, 11:16 AM

Sometimes the old florescent lights will do this. CFL and LED can also cause this. try turning off lights and see if that helps.

If the problem goes away then turn on lights one at a time until it comes back.

MikeBmusic · #10 03-23-2018, 11:27 AM

Old dimmer switches can also cause the problem.

muscmp · #11 03-23-2018, 11:46 AM

Quote:

Originally Posted by clintj

No. No, no, no, no. Do NOT do this. That works on older amps because one leg of the wiring in the amp is referenced to ground through a death cap. Modern amps don't do this, and if an issue develops where the amp chassis becomes electrically live, it can cause serious injury or death because you have now defeated the safety ground - YOU are now the ground. You also defeat the amp maker's efforts to have the fuse first in the power wiring, which is also important for the safety of you and your amp.

Buy an outlet tester, they're $10 or less at Home Depot. Make sure you have a properly wired outlet, and if you don't, tell your landlord. Every guitarist should have one of these in their gig bag, IMO.

Again, don't risk your safety just to have a quiet amp.

big plus to clintj on this!

you may have to get some copper tape and tape the routed area underneath the pickguard. make sure the tape is then to ground. additionally there is a way to apply that same tape to the pickups themselves. but, follow clintj's recommendation first.
play music!

LouieAtienza · #12 03-23-2018, 02:23 PM

GC carries this thing called HumX which plugs between your outlet and amp. Works well enough to keep in your gig bag just in case...

KevWind · #13 03-24-2018, 07:59 AM

Quote:

Originally Posted by Dan Barracuda

Hey guys,

Today was a crazy day. I went to GC to pick up my amp (Egnater Tweaker!) this afternoon. Was soooo excited. Went home, and started hearing this odd humming sound. Really wasn’t sounding great. My friend (who works at GC) came over to check it out. He couldn’t figure out what it was, but he speculated that it might have to do with the wiring of my really old apartment. Went to GC to pick up a power conditioner (I think is the name) power strip (Furman). Went back home, and it didn’t fix the problem.. Then we drove to my rehearsal space with my new strat and amp. Plugged in, and it was totally fine. Sounded so amazing! So now I know that it’s not the amp or the strat. It must be something to do with my apartment. Does anyone have any experience with this issue?

Thanks!

Not specifically that issue but having been involved in remodeling some old buildings as a carpenter and project forman ,here are some general thoughts on things to consider

"Really old" is relative, first are your outlets 2 prong or 3 prong (really old is actually only two and there is no 3rd 1/2 round hole )
If they are 3 (which I suspect since you did not mention them) unfortunately there are two possibilities if in fact the building is old enough to have actually been a two wire system.
#1 is that the old system was actually replaced with a 3 wire system
# 2 the owner simply replaced the 2 wire outlets with 3 wire outlets and the ground is not really connected

I am not an electrician so there may be a way to use a meter to determine this But another way to determine is to pull the face plate and inspect the box and socket ( note you should turn the power off to that circuit first )

Besides what others have said another troubleshooting method is plug in the guitar and amp and go the the breaker /fuse panel and determine what circuit they are on, then start systematically turning of the other circuits to see it the hum goes away. If it does then the problem is likely some connection on the problem circuit.

vindibona1 · #14 03-24-2018, 03:04 PM

Quote:

Originally Posted by Dan Barracuda

Hey guys,

Today was a crazy day. I went to GC to pick up my amp (Egnater Tweaker!) this afternoon. Was soooo excited. Went home, and started hearing this odd humming sound. Really wasn’t sounding great. My friend (who works at GC) came over to check it out. He couldn’t figure out what it was, but he speculated that it might have to do with the wiring of my really old apartment. Went to GC to pick up a power conditioner (I think is the name) power strip (Furman). Went back home, and it didn’t fix the problem.. Then we drove to my rehearsal space with my new strat and amp. Plugged in, and it was totally fine. Sounded so amazing! So now I know that it’s not the amp or the strat. It must be something to do with my apartment. Does anyone have any experience with this issue?

Thanks!

Yes... I had this issue. It's called "dirty electricity". I've tried the Furman, multiple filters, DI boxes.. tried it all. It was throughout the building. And like you I'd take my gear somewhere else and it was clear as a bell. The amount of noise was unbearable at certain times and more liveable at other times. It has improved greatly (not sure what they did besides change the electric meters); sometimes gone sometimes not. I feel your pain.