Shielded cable

[Bluemoon]

Got a bad hum on my Fender blues jr. It is as silent as a ghost when nothing is plugged into it. It hums when I a cable (no guitar plugged in). It hums even more once I add my LP. The hum increases when I turn up the volume, and it gets really bad when I turn up the gain or hit the "fat" switch. This is second BJ that has done. I returned the first one because I thought it was the amp. The new one does the same thing.

 

I've moved the amp around the house...makes no difference. I have tried an older cable--makes no difference.

 

My old Valve Jr. hummed too--but I figured it was because it was a cheap amp.

 

My guess is that I am picking up RFI from dimmers, a computer or some other crap in my house.

 

Any quick fixes (tube change, better cable, power conditioner)? Or just live with it. I was thinking of replacing the instrument cable--which is a dimarzio 10 footer. Who makes a good shielded cable?

[ALIEN8]

Sounds like you have a grounding issue, and not a shielding issue.

 

Unplug, and try wiggling the tubes to make sure they sit tight. Every amp hums with a cable plugged in with nothing attached. Check the grounding on your guitar first, if it gets worse when you plug in the guitar, and doesn't go away when you touch the strings, then your guitar isn't grounded, and needs work to re-connect the ground wire.

[Bluemoon]

Sounds like you have a grounding issue' date=' and not a shielding issue.

 

Unplug, and try wiggling the tubes to make sure they sit tight. Every amp hums with a cable plugged in with nothing attached. Check the grounding on your guitar first, if it gets worse when you plug in the guitar, and doesn't go away when you touch the strings, then your guitar isn't grounded, and needs work to re-connect the ground wire. [/quote']

 

It does get worse when I plug in my LP. But it goes away when I touch the strings or just about any other metal part on the guitar. So it sounds like the guitar is properly grounded and doing it's job, right?

[MikeRom]

Got another guiatr you can try? If not your own, a neighbors or frineds.

[Bluemoon]

No other electric. May have to go down to the local music store and borrow one.

 

Though I am not sure it is the guitar. If I increase the volume on the amp (without just the cord plugged in), especially gain, the hum will increase. I was thinking the cable was acting as an antennae and the guitar just further enhanced it. But then again, I am no engineer.

[Thundergod]

Go to another place with the amp and guitar (pain in the *** I know), for example your parent's house or a friend's house... if that takes care of the problem, you are screwed!

 

I have the same problem in my studio, funny thing is when I move any amp guitar or fx home and play them there, there is no problem... (at home, not even single coil guitars give me any hum, not even whit high gain... strange isn't it?)

 

Turns out the building where I have my studio has huge ground issues: too much stuff into the same transformer; 10 floors and 2 depts. each floor, I am in the 1st floor alone and never had problem til the day one of those places where you can use computers, internet and make copies openned beneath my place (24 computers and 12 copying machines)... they were the ones that caused the whole mess because they had too much stuff going directly into the grid (ok, so did I but I was there first)

 

This has been going on for close to a year... the problem only seems to afect guitars (more stragely, those with humbuckers make more noise, and the worst is when I plug in the one with EMGs).

 

I had an tech do some research and he concluded I have to buy a transformer that will work exclusively for my studio... that is not an option being in Ecuador... some idiot at the company might think "no one will notice" and start using it for other buildings and stuff... (so I would pay for nothing and those f-ckers are expensive).

 

I also learned that the US embasy (right across the street, I can see those guys from the rear window) will soon install a device that interferes with all signals... (cellphones, wireless systems, radios, and of course that affects guitars) so the problem is about to become bigger.

 

I had to move out anyway (I need more space, like 4 or 5 times more... ), so right now I am in the hunt for a nice, kind of huge, property at an incredibly low price, where I can place the studio, 2 conference rooms, a small wharehouse, the cab building facility and some parking spots. Hard to find, but already have 2 candidates, and they are close to my house .

[RichCI]

It does get worse when I plug in my LP. But it goes away when I touch the strings or just about any other metal part on the guitar.

 

That's normal.

[HeadCase]

It does get worse when I plug in my LP. But it goes away when I touch the strings or just about any other metal part on the guitar. So it sounds like the guitar is properly grounded and doing it's job' date=' right?[/quote']

I'm gonna disagree w/ that one. I've had similar grounding issues. When you touch metal you are the ground.

I think at the very least, the guitar has a ground problem.

 

Blue & Thunder, good luck... nothing worse than a can 'o worms.

[Bluemoon]

Go to another place with the amp and guitar (pain in the *** I know)' date=' for example your parent's house or a friend's house... if that takes care of the problem, you are screwed!.[/quote']

 

That's my next step. Thanks.

[Bluemoon]

I'm gonna disagree w/ that one. I've had similar grounding issues. When you touch metal you are the ground.

I think at the very least' date=' the [u']guitar[/u] has a ground problem.

 

Blue & Thunder, good luck... nothing worse than a can 'o worms.

 

I think it is the other way around. If the guitar wasn't grounded right, it would hum and hiss if you touched the strings. If the hum goes away when you touch them, it means the guitar is properly grounded. At least that is my understanding.

[SRV-Zeppelin]

Hey Blue, I have the exact same problem, but I believe the issue's with my LP. My SG does not hum at all, but my LP does unless I'm touching something metal on the guitar. God forbid I have to get all its wiring re-shielded...

[Bluemoon]

Hey Blue' date=' I have the exact same problem, but I believe the issue's with my LP. My SG does not hum at all, but my LP does unless I'm touching something metal on the guitar. God forbid I have to get all its wiring re-shielded...[/quote']

 

That would suck. I wonder if that would be covered under warranty. Mike?

[RichCI]

I still think it's normal. Every guitar I own makes noise when the pots are open and I'm not touching something metal connected to the strings or electronics - that includes my LP, Strat, Tele, SG Jr, etc.

[Bluemoon]

I still think it's normal. Every guitar I own makes noise when the pots are open and I'm not touching something metal connected to the strings or electronics - that includes my LP' date=' Strat, Tele, SG Jr, etc.[/quote']

 

I agree. I am not sure it is the guitar--unless it isn't properly shielded. It for sure isn't a ground issue. I actually put a ground lift on the amp (plugged the three-prong plug into a two-prong) to make sure it wasn't a ground loop issue. When I touched a the metal on the guitar I would get a popping noise. That is the noise you would get if the guitar wasn't properly grounded. It is not a pretty noise.

 

My goal is find a way to reduce the noise--not necessarily eliminate it.

[elessar820]

All of my guitars hum too, especially the LP. I shielded the cavities with aluminum tape and made sure the wire for the long run from the killswitch to the rest of the electonics was shielded, after that it still hums, but not as badly.

[SRV-Zeppelin]

I still think it's normal. Every guitar I own makes noise when the pots are open and I'm not touching something metal connected to the strings or electronics - that includes my LP' date=' Strat, Tele, SG Jr, etc.[/quote']

 

You just blew my mind, Rich.

 

I just realized it's only when my volumes are on 10 that it hums... (that is what you meant by "pots are open" right?)

 

I prefer to keep my amp at one setting and fool around with my volume pots to adjust my tone... and when I've got them down at about 6 or 7 the hum is gone.

 

Thanks!

[DiamondJig]

Is this something that just started happening ? Does the amp have a ground lift switch ? Try a 2 prog plug or add an adpter that is only 2 progs and don't use the ground lug. All my guitars will do it some worse that others, the hotter the pickups or more gain/distortion/vol the worse it gets, all except my active EMG's quite as a mouse all the time, they are not grounded like normal pickups and the are low impedance, the build in preamp boosts the signal.

[Bluemoon]

I tried the ground lift and that didn't work.

 

I actually got off the phone with my go-to luthier. He said it is for sure not a ground issue with the guitar. If you touch the strings and the hum doesn't go away then you have a ground issue. The guitar is doing what it is supposed to do by eliminating the hum when you touch the strings.

 

He says it is something in the house (dimmers, etc) or the bad wiring in the house (my house is 60 years old).

[surfpup]

I assume you are plugging directly into the amp (no pedals)? I've had hum come from cords between pedals before. You might also try unplugging some big stuff in your house with the amp on (and humming). Computers, TVs, lights, etc. You might find one item is causing the trouble.

[RichCI]

You just blew my mind' date=' Rich.[/quote']

It's a gift.

 

I just realized it's only when my volumes are on 10 that it hums... (that is what you meant by "pots are open" right?)

 

I prefer to keep my amp at one setting and fool around with my volume pots to adjust my tone... and when I've got them down at about 6 or 7 the hum is gone.

 

Thanks!

Yes, that's what I meant by "pots are open."

 

It's really prominent with my Strat since it has single coil pups and, the weird thing is, the least amount of hum seems to be when the pots are somewhere between all the way down and all the way up. Go figure.

[SolidGuitar]

I'm gonna disagree w/ that one. I've had similar grounding issues. When you touch metal you are the ground.

I think at the very least' date=' the [u']guitar[/u] has a ground problem.

 

I think when you touch metal on the guitar, the guitar grounds you. I read that our bodies have resistance and causes interference. If you put your guitar down while it is turned up and move away from it, the noise should get quieter. This site has some good information. http://www.guitarnuts.com/index.php Maybe you can find something on there that will help you tame the noise.

[Bluemoon]

i think i am going to take a ton of drugs. perhaps that will get rid of the hum...at least it will eliminate the hum in my head

[Bluemoon]

I assume you are plugging directly into the amp (no pedals)? I've had hum come from cords between pedals before. You might also try unplugging some big stuff in your house with the amp on (and humming). Computers' date=' TVs, lights, etc. You might find one item is causing the trouble.[/quote']

 

Tried it with and without a pedal. It is louder with the OCD on. What is strange is that I didn't notice for the first few weeks I had the amp. During those two weeks I used a Weber attenuator. Perhaps that cut out the noise. I sent my old attenuator back for an upgrade to the next size--should have a new model early next week.

[retrosurfer1959]

I had a problem with a ceiling fan in a different room causing real problems I was luckythough, a new dedicated circuit when I enlarged my home studio resolved all the issues.

[Bluemoon]

So here is the final assessment. It is two heater fans in my upstairs bedrooms that are causing the hum. The are designed with thermistors--which help moderate fan speed and heat based on the temperature in the room. I guess they are more efficient than thermostats. They work by moderating the flow of current to the unit (I think). The manufacturer of the unit admits that they have had complaints that their units interfere with AM radios, but nothing else. Well, now they know they also screw up guitar amps too!!!

 

I could kick myself. The wife wanted to buy the cheaper thermostat model. I wanted some a little more high-tech (and more energy efficient), so I went for the upgraded units.

 

The lesson here is listen to the wife.