Questions about single coil noise

3

357mag

New member
A couple of questions concerning single coil pickups:

1. I may be installing some single coils in my Strat in the near future. I'm using Area 61's now which I like but I do go through pickup experimention syndrome from time to time. I will be running my Strat through a distortion pedal plus a few others and then into my 50 watt Marshall. I play mostly classic rock in the band I'm in. Will the use of a noise gate help to remove some of the infamous 60 cycle hum? Anyone here using single coil pickups into a distortion pedal? How are you faring?

2. Blackmore, Trower, and Hendrix all used single coils. Let's exclude Hendrix cuz when you listen to his live recordings you can hear noise but when I listen to Robin Trower or Ritchie Blackmore live I don't hear any noise. So how did they do it? Did they figure out during sound check where to stand on stage to minimize the hum? You would think that you would at least a little hum as they turn on the volume on their guitars before the song starts. And these guys played loud also so you would think hum would be a serious issue.
 
Seems like somebody was just asking about this the other day. Maybe this is the thread I'm thinking of. As I recall, the consensus was that you'd have better luck with a good shielding job than with a noise gate.
 
Noise gates are notorious on guitar tracks for "gating" parts of the notes (like fades) that you don't want gated. Shielding, as noted, is the way to go.
 
+1 on shielding, it helps. and please don't use studio recording as your gauge - when the guitarist is not playing the noise can be edited out by turning off the channel or pulling down the fader (or now by visually erasing the noise on the computer screen). and when the guitarist is playing, especially with overdrive, the noise don't matter :D

some noise is natural and can add to authenticity - in music perfection is in the imperfections.
 
I rather like the noise of my single coils - they make an awful racket in front of a CRT though.
Sheilding is quite a good option - easy and doesn't degrade the signal.
 
357mag said:
Shielding will do nothing. Tried it years ago. Does nothing.
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that doesn't mean it does nothing. there could be several reasons why it did nothing for you (and no offense, please)

- could be that existing shielding was already adequate and so no perceived difference (noise still exists with shielding, just less of it)

- could be that shielding wasn't done properly (again, no offense, I don't know you, so I'm just guessing, maybe it's not the case), i.e. the shield wasn't properly grounded, ground loops weren't eliminated

- could be a wiring problem in your house (I have that) - if the problem is with the AC outlet, shielding won't help. Light dimmers, certain appliances, etc.

- could also be the amp - if there's a problem there, I suppose shielding wouldn't help either.

Shielding works - for 60-cycle hum caused by single-coil pickups and guitar wiring "picking up" (like antenna) the interference around.
 
I may be mistaken on this but I thought I read on Kinman's site that he also said shielding does nothing to eliminate 60 cycle hum. It was a long time ago I read that and maybe he didn't say that but...
 
357mag said:
I may be mistaken on this but I thought I read on Kinman's site that he also said shielding does nothing to eliminate 60 cycle hum. It was a long time ago I read that and maybe he didn't say that but...
Click to expand...

well, I'm definitely not looking for "any trouble" :) and I don't want to start an argument, but i thought that shielding's sole purpose is to screen out interference. that's why metal covers are placed on pickups, that's why cables and pickup leads are covered with a braided shield, people shield amps, etc.

shielding won't eliminate the noise (single-coils picking up the 60-hum), but will reduce it - whether or not it will be heard depends on how bad it was to begin with. it certainly does "something" in the several guitars/basses that I've shielded with foil.
 
357mag said:
I may be mistaken on this but I thought I read on Kinman's site that he also said shielding does nothing to eliminate 60 cycle hum. It was a long time ago I read that and maybe he didn't say that but...
Click to expand...

I certainly haven't found that to be my experience. I used to have substantial hum before I did a complete body cavity shielding job with copper foil tape. Now, my single coils basically don't hum.

That said, I have noticed a HUGE difference between pres as to the amount of hum. The pres in my Behringer DI don't produce any 60 Hz hum (and it's not a notch filter, either---it was designed for bass, where 60 Hz is approximately the second fret on your A string). If you plug the same guitar into a FIREPOD's instrument pre with the same cable, it hums badly.

I'm not sure what this tells us beyond that the FirePod really should have used a built-in power supply with a three-prong power cord, but.... :)
 
when you sheild the cavity of the guitar do you ground it to one of the pots? and for those of us with the through body bridge tremelo do we put shielding in that part of the guitar aswell?
 
MatchBookNotes said:
when you sheild the cavity of the guitar do you ground it to one of the pots? and for those of us with the through body bridge tremelo do we put shielding in that part of the guitar aswell?
Click to expand...



To answer your questions, yes, the shielding needs to be grounded, but don't worry about it because as long as the pot bodies are touching the shielding you're fine; no, you do not need to shield the trem cavity.


Shielding will help, but it is not a perfect solution as you can not shield the front side of the pickups. If you use real single coil pickups, you will always get SOME noise - unless you build a room which is completely shielded, which most people do not have. I've heard of some studios doing that, but I've never been in one myself.

Don't buy anybodies suggestion that shielding needs to be complicated. It doesn't. It doesn't need to be copper, and you don't need to solder overlapping pieces of foil together. The cheapest way to do one guitar is with aluminum foil and a spray adhesive, and that will do just as good of a job as any other method - though it is more time consuming. (If you need to do 20 guitar, that's another story, and between the materials and the labor involved, shielding paint is the way to go - but don't worry about it if you are only doing one.) The adhesive backed copper foil is easier to use than aluminum foil and spray adhesive, but it really doesn't work any better and costs WAY more than you need to spend. Cover all the surfaces of the pickup/control cavities, and the inside of the pickguard. Make sure that when the pickguard is installed, there is contact between the pickguard foil and the cavity foil. What you are trying to do is create a "cage" around the electronics (it's called a "Faraday Cage" - look it up). I'll also go with Dan Erlewine here and say not to bother shielding the jack cavity on a strat, as it is WAY too easy to short out the output. Use a shielded cable to the jack, and call it good. You will never hear the difference.

And if anyone tells you to isolate the bridge ground with a cap, ignore them - they are just repeating a really stupid myth from the internet which has no practical value - and limited theoretical value as well, unless you are stupid enough to bypass the fuse in your amp.


Light

"Cowards can never be moral."
M.K. Gandhi
 
357mag said:
Shielding will do nothing. Tried it years ago. Does nothing. But I discovered a new solution...

http://guitars.musiciansfriend.com/...-Hum-Debugger-Hum-Eliminator-Pedal?sku=150136
Click to expand...



Incorrect. It doesn't solve every issue, and it is far from a perfect solution, but shielding IS extremely effective at reducing certain kinds of hum - including any kind of RF. It's not going to help with most 60 cycle hum because most 60 cycle doesn't come through the pickups - it comes through the amp. Nothing done to the guitar will get rid of noise that is being created in the amp. For that, you usually have to mess with the ground scheme or the lead dress in the amp. Or both, of course. Or the cable routing on the stage. Or the stage circuiting. Or any number of other things.


Light

"Cowards can never be moral."
M.K. Gandhi
 
Light said:
And if anyone tells you to isolate the bridge ground with a cap, ignore them - they are just repeating a really stupid myth from the internet which has no practical value - and limited theoretical value as well, unless you are stupid enough to bypass the fuse in your amp.
Click to expand...

Won't this help prevent (or perhaps just minimize) your getting shocked from polarity discrepancies between amps, etc., from which your amp's fuse will not? Of course, only when holding your strings and touching the other mic, guitar, whatever. I've never tried it, but it sounded like a reasonable idea to me. I just fixed my amp's ground instead.
 
Light said:
To answer your questions, yes, the shielding needs to be grounded, but don't worry about it because as long as the pot bodies are touching the shielding you're fine; no, you do not need to shield the trem cavity.


Shielding will help, but it is not a perfect solution as you can not shield the front side of the pickups. If you use real single coil pickups, you will always get SOME noise - unless you build a room which is completely shielded, which most people do not have. I've heard of some studios doing that, but I've never been in one myself.

Don't buy anybodies suggestion that shielding needs to be complicated. It doesn't. It doesn't need to be copper, and you don't need to solder overlapping pieces of foil together. The cheapest way to do one guitar is with aluminum foil and a spray adhesive, and that will do just as good of a job as any other method - though it is more time consuming. (If you need to do 20 guitar, that's another story, and between the materials and the labor involved, shielding paint is the way to go - but don't worry about it if you are only doing one.) The adhesive backed copper foil is easier to use than aluminum foil and spray adhesive, but it really doesn't work any better and costs WAY more than you need to spend. Cover all the surfaces of the pickup/control cavities, and the inside of the pickguard. Make sure that when the pickguard is installed, there is contact between the pickguard foil and the cavity foil. What you are trying to do is create a "cage" around the electronics (it's called a "Faraday Cage" - look it up). I'll also go with Dan Erlewine here and say not to bother shielding the jack cavity on a strat, as it is WAY too easy to short out the output. Use a shielded cable to the jack, and call it good. You will never hear the difference.

And if anyone tells you to isolate the bridge ground with a cap, ignore them - they are just repeating a really stupid myth from the internet which has no practical value - and limited theoretical value as well, unless you are stupid enough to bypass the fuse in your amp.


Light

"Cowards can never be moral."
M.K. Gandhi
Click to expand...

will super glue and some kind of even spreader work just as well as the spray adhesive? I question my coordination with such sticky things, I may end up aluminium foiling my entire guitar just to give it a consistent look.
 
What Light said is pretty detailed and to the point.

I've done it both ways - strats are fairly easy with aluminum foil. you can use whatever will hold the foil to the wood and even just use electrical tape or scotch tape to stick overlapping pieces together - it'll be a continous connection electrically.

For my "les paul" (copy) i ordered copper foil - because the cavities are smaller and I figured it'd be easier to work with. Yes, it's more expensive, but not that big a deal - 1 purchase will probably last you a lifetime, if you don't shield friend's guitars for free, like I do. If you're wondering why I shielded a humbucker guitar - it's because I use coil-splits on it.

The advice on not shielding the jack cavity is good (use shielded cable instead), but for me I simply wrap the jack with electrical tape, so that the "hot" doesn't touch the foil. Now that I have some shielded wire, I'd probably use that.
 
I don't see a big problem with gating. If you play around with the decay/threshold, you'll be fine. You wont hear 60 cycle hum over the notes you play anyway.
 
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