Terrible hum when TV is on in room

[eyemack]

I am just a home player, and I know there are a whole stack of posts about hum on the JM, but I thought I'd ask this any way.

In essence, whenever the TV is switched on in my playing room - which does happen quite a lot if I want to keep one eye on the football! - then there is horrible hum from my Am Pro II JM. This does not occur with my Am Pro II Strat or Am Performer Tele, and there is very little hum from the JM without the TV on.

It's so bad, that I tend to change guitars until I switch off the TV.

Is this normal, would you say?

[Larry Mal]

Yeah, sort of, I'd say. Flat panel type TVs and computer monitors are lousy with noise causing interference. I can't explain why it would happen to your Jazzmaster more except that Jazzmaster pickups are wider and maybe are more receptive.

[eyemack]

Thanks. I would say that there is a huge difference between the Strat/Tele and the JM. Maybe because the pickups are wider, but not sure.
Is there anything that can be done to improve the situation with the JM?

[ainm]

When it comes to hum, I sort of miss CRT TVs.

[Larry Mal]

Thanks. I would say that there is a huge difference between the Strat/Tele and the JM. Maybe because the pickups are wider, but not sure.
Is there anything that can be done to improve the situation with the JM?

I took a quick look and seem to see that the American Pro 2's have that aluminum plate under the pick guard there, I wonder if there is any more shielding than that? Are the body cavities shielded or just bare wood?

That would be my first thing to look at.

[jthomas]

I usually have both a flat panel computer monitor and a flat panel television set on in my small practice space. I really do not have much hum either with single coils or humbuckers. The amps are maybe 15 feet away from the electronics and I can be at 4 feet or so from the flat panels with a guitar. I do get a characteristic sound in the amps when my computer accesses the hard disk, but it's not much. The amps are located 90 degrees away from the direction of the flat panels, but I do not know if that makes any difference.

[alexpigment]

A few questions to help narrow it down:

1) What sort of TV is this? LCD/LED, Plasma, OLED, etc? I've never noticed this sort of thing myself (I've even tested turning on/off my monitors and TV), but I've only ever owned LCD/LED and OLED - no idea how plasma affects hum. I suppose there's always the possibility that certain TV models have shielding to prevent EMI while others don't. I've never been the type to go out on Black Friday and find the biggest cheapest budget brand TV - and I mean no disrespect to anyone that does - so perhaps there is a tier in which noise is more prevalent.

2) Does the hum go away when touching the strings? If not, shielding probably won't do too much (though I do recommend shielding and twisting wires as necessary).

3) Do you have a small battery powered amp you could try in the same room? It might be worth testing this to rule out the possibility that the noise is coming through the electrical lines to your amp when the TV is on.

As for why this is happening with your JM and not the others, JM pickups are notorious for picking up my noise than other Fender designs. I believe it's just that the coil windings are wide and flatter rather than narrow and taller. It's the reason I put a dummy coil in all of my offsets

[eyemack]

Thanks a lot, guys for your responses.

A few questions to help narrow it down:

1) What sort of TV is this? LCD/LED, Plasma, OLED, etc? I've never noticed this sort of thing myself (I've even tested turning on/off my monitors and TV), but I've only ever owned LCD/LED and OLED - no idea how plasma affects hum. I suppose there's always the possibility that certain TV models have shielding to prevent EMI while others don't. I've never been the type to go out on Black Friday and find the biggest cheapest budget brand TV - and I mean no disrespect to anyone that does - so perhaps there is a tier in which noise is more prevalent.

2) Does the hum go away when touching the strings? If not, shielding probably won't do too much (though I do recommend shielding and twisting wires as necessary).

3) Do you have a small battery powered amp you could try in the same room? It might be worth testing this to rule out the possibility that the noise is coming through the electrical lines to your amp when the TV is on.

As for why this is happening with your JM and not the others, JM pickups are notorious for picking up my noise than other Fender designs. I believe it's just that the coil windings are wide and flatter rather than narrow and taller. It's the reason I put a dummy coil in all of my offsets

1) It's a LCD/LED 65" Samsung.
2) yes, the hum goes away when I touch the strings.
3) I tried my battery amp, and there is no hum with it.

I took a quick look and seem to see that the American Pro 2's have that aluminum plate under the pick guard there, I wonder if there is any more shielding than that? Are the body cavities shielded or just bare wood?

That would be my first thing to look at.

Looks like it's painted but not shielded, unless it's some kind of shielding paint!

[electric__ralph]

“ yes, the hum goes away when I touch the strings.”
Your guitar isn’t grounded properly. Check the wire that goes from ground to the bridge/tailpiece, it’s broken or missing. Right now your strings are acting like a giant antenna.

[alexpigment]

OK, so if the battery powered amp doesn't hum, it might be worth testing a Furman SS-6B power strip to plug in your amp/effects. Secondly, since the hum goes away when you touch your strings, shielding is in order. Just make sure the copper shielding tape says it has conductive adhesive, which will make the job a lot easier. If you shield your entire guitar cavity (including under where the pickups go) and also the entire back side of your pickguard, you should be able to get rid of most/all of the hum that occurs when not touching the strings. It's also worth making sure you have a small lip of shielding on around the cavities so that the pickguard and cavity shielding touch in a few places.

[GilmourD]

“ yes, the hum goes away when I touch the strings.”
Your guitar isn’t grounded properly. Check the wire that goes from ground to the bridge/tailpiece, it’s broken or missing. Right now your strings are acting like a giant antenna.

Also make sure your amp is properly grounded. That means that the ground pin is intact (not broken off), you're not using a three-to-two prong adapter, but also that your outlets themselves are correctly wired. Fortunately I would never have a good reason to plug any of my amps into outlets in my kitchen but two of them aren't grounded correctly when I test them with a tester like this. Unfortunately I don't own the house, but everything I plug into them is two-prong anyway, so it's not a big deal.

That said my Jazzmasters are decidedly noisier than any of my other guitars, even when fully shielded. I want to try those FunkedUpGuitar aluminum covers when he makes another batch in anodized black and see both how well they shield a Jazzmaster pickup but also if (or, really, how much) they affect the treble response.

[alexpigment]

“ yes, the hum goes away when I touch the strings.”
Your guitar isn’t grounded properly. Check the wire that goes from ground to the bridge/tailpiece, it’s broken or missing. Right now your strings are acting like a giant antenna.

This is actually a common misunderstanding. If touching the strings causes the hum to go away, it actually means that the guitar *is* grounded properly, but it is insufficiently shielded (i.e. shielding adequately will make it so that there is no additional noise that occurs when taking your hands off the strings). I just wanted to clarify this before we lead the OP down the wrong path.

[eyemack]

Also make sure your amp is properly grounded. That means that the ground pin is intact (not broken off), you're not using a three-to-two prong adapter, but also that your outlets themselves are correctly wired. Fortunately I would never have a good reason to plug any of my amps into outlets in my kitchen but two of them aren't grounded correctly when I test them with a tester like this. Unfortunately I don't own the house, but everything I plug into them is two-prong anyway, so it's not a big deal.
That said my Jazzmasters are decidedly noisier than any of my other guitars, even when fully shielded. I want to try those FunkedUpGuitar aluminum covers when he makes another batch in anodized black and see both how well they shield a Jazzmaster pickup but also if (or, really, how much) they affect the treble response.

I've checked the mains before, and it is all well grounded. The amps are OK as well. Thanks.

OK, so if the battery powered amp doesn't hum, it might be worth testing a Furman SS-6B power strip to plug in your amp/effects. Secondly, since the hum goes away when you touch your strings, shielding is in order. Just make sure the copper shielding tape says it has conductive adhesive, which will make the job a lot easier. If you shield your entire guitar cavity (including under where the pickups go) and also the entire back side of your pickguard, you should be able to get rid of most/all of the hum that occurs when not touching the strings. It's also worth making sure you have a small lip of shielding on around the cavities so that the pickguard and cavity shielding touch in a few places.

Thanks. I've ordered some tape, but am not confident doing that job myself. How hard is it to do? The back side of the pickguard is already shielded from the factory.

[GilmourD]

Also make sure your amp is properly grounded. That means that the ground pin is intact (not broken off), you're not using a three-to-two prong adapter, but also that your outlets themselves are correctly wired. Fortunately I would never have a good reason to plug any of my amps into outlets in my kitchen but two of them aren't grounded correctly when I test them with a tester like this. Unfortunately I don't own the house, but everything I plug into them is two-prong anyway, so it's not a big deal.
That said my Jazzmasters are decidedly noisier than any of my other guitars, even when fully shielded. I want to try those FunkedUpGuitar aluminum covers when he makes another batch in anodized black and see both how well they shield a Jazzmaster pickup but also if (or, really, how much) they affect the treble response.

I've checked the mains before, and it is all well grounded. The amps are OK as well. Thanks.

OK, so if the battery powered amp doesn't hum, it might be worth testing a Furman SS-6B power strip to plug in your amp/effects. Secondly, since the hum goes away when you touch your strings, shielding is in order. Just make sure the copper shielding tape says it has conductive adhesive, which will make the job a lot easier. If you shield your entire guitar cavity (including under where the pickups go) and also the entire back side of your pickguard, you should be able to get rid of most/all of the hum that occurs when not touching the strings. It's also worth making sure you have a small lip of shielding on around the cavities so that the pickguard and cavity shielding touch in a few places.

Thanks. I've ordered some tape, but am not confident doing that job myself. How hard is it to do? The back side of the pickguard is already shielded from the factory.

It's most certainly not difficult at all. Get some small dowels or something to help you get in the corners and watch this.

https://www.youtube.com/watch?v=-mLBo4y9t8Y

[eyemack]

That's not difficult???
I'll give it a go.