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Author
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Topic: Getting rid of hum in single-coils
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David Spangler
Member From: Kerrville, TX USA
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posted 13 March 2006 12:10 PM
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A friend showed me an article where the author uses a .47uF 400 or greater V capacitor between the string ground and the electrical ground. It does 2 things, it protects the user against electrical shock and greatly reduces the 60 Hz buzz. He brought his Strat over and showed me the difference and it was remarkable. Seems like it would also work on a steel if you can separate the strings from the electrical ground.------------------
David Spangler |
David Spangler
Member From: Kerrville, TX USA
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posted 13 March 2006 09:51 PM
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I just read back through the posts and what I was referring to was covered in Larry Robinson's post:Quote:
.."explicit instructions on hum elimination/reduction for Tele/Strat guitars at www.guitarnuts.com which might be helpful.." ------------------
David Spangler |
Al Sato
Member From: Texas Hill Country
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posted 13 March 2006 11:05 PM
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Thanks, Dave, for reminding me. I needed to thank Larry for the pointer. This technique does in fact reduce hum. Thanks, Larry!Al ------------------
So many stringed instruments, so little time... |
Bob Hoffnar
Member From: Brooklyn, NY
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posted 13 March 2006 11:33 PM
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You guys know more about this than me so I was wondering why I just don't like the sound of extra EQ in my signal chain to deal with problems. If I use any sort of eq to deal with hum the tone sounds sort of false like when there are phasing problems in the studio. Notching out unwanted frequencies in a mix works fine though on recorded tracks. It seems like when I add another EQ device in my chain after or before the pre amp EQ already there something screwy happens to the sound.
The only thing that works for me on a noisy stage is to pick harder and use my volume ped as a cut off inbetween songs.------------------
Bob
upcoming gigs
My Website 
[This message was edited by Bob Hoffnar on 13 March 2006 at 11:35 PM.]
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Donny Hinson
Member From: Balto., Md. U.S.A.
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posted 14 March 2006 04:34 AM
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quote:
A friend showed me an article where the author uses a .47uF 400 or greater V capacitor between the string ground and the electrical ground. It does 2 things, it protects the user against electrical shock and greatly reduces the 60 Hz buzz.
Sounds like you're "protected" if you're touching the strings, but not when you're touching the control knobs? Please explain. |
David Spangler
Member From: Kerrville, TX USA
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posted 14 March 2006 07:21 AM
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Donny, you're right! The protection would obviously be better on a guitar with plastic knobs, like a Strat. The Tele is another story.But, my friend had just built a FrankenStrat with single coils and it was really noisy. After the addition of the capacitor (I gave him a .1 @ 600V because I didn't have a larger value) and the noise reduction was, subjectively, in the 80% range. I noted that Weber, Hoffman and Mojo have the larger value caps. ------------------
David Spangler |
Dave Mudgett
Member From: Central Pennsylvania, USA
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posted 14 March 2006 11:33 AM
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quote:
... I was wondering why I just don't like the sound of extra EQ in my signal chain to deal with problems. If I use any sort of eq to deal with hum the tone sounds sort of false like when there are phasing problems in the studio.
Well, a lot depends on the filters used. EQs are what are known as "linear filters". Such filters change not only the amplitude of various frequencies, but also the phase relationship at those frequencies. There are lots of ways to design linear filters to give the same amplitude frequency response, but the phase changes may be more or less depending on what design is used. The other factor is how much amplitude cut/gain is used in a variable filter. Usually, for a given filter design, the more amplitude cut/gain is used, the more phase changes there are. One also has to worry about "nonlinear" affects in any piece of electronic gear. Cheap EQs may distort, compress, expand, compand, or otherwise interfere with the clean signal. In fact, as noted earlier, some of the noise reduction units use a downward expander approach. To me, if the guitar sounds good naturally, EQ should be used as minimally as possible. There are times when a little bit really helps, but I don't think it's a cure for a really bad initial frequency response. Some of the stuff we're talking about here involves radical notch filtering of certain frequencies. One has to expect that if there's musical content in that band of frequencies, they will sound pretty poor in the end mix. The only approach I've seen here that's really different is the Presonus 624 EQ - it uses hum canceling - identify and subtract the hum signal - instead of selective multiplicative frequency attenuation. If I could find a portable unit that just did the ANC without the EQ for a couple hundred dollars, I'd grab it. |
Dave Mudgett
Member From: Central Pennsylvania, USA
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posted 14 March 2006 11:57 AM
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quote:
Sounds like you're "protected" if you're touching the strings, but not when you're touching the control knobs? Please explain.
Sure, that's correct. This is a lot better than nothing - one is not usually constantly in contact with the knobs the way one is with the strings/bridge. The issue is to protect against a ground fault. So the correct way to deal with this the larger issue is: 1. Make sure a ground fault can't happen with auxiliary equipment. 2. If one wants still more protection against a ground fault than this, then isolate the knobs, switches, and jack, and use isolated cables. The tradeoff here is that string grounding helps noise by using your body as a EFI shield. With humbucking pickups, it's possible to shield components and wiring and remove the string ground. But that won't work with single-coil pickups, which is the issue in this thread. I've tried using various techniques to shield single-coils, but anything I've ever tried either didn't work or significantly affected the pickup's tone. Years ago, as an experiment, I carefully shielded a real noisy P-90 pickup in some type of non-magnetic but conductive shielding, painting the control cavity with conductive paint - all the wiring was braided shield - but it still didn't help the single-coil hum very much. I sure wouldn't do that to a vintage guitar, anyway. This is an issue that's not going away. |
Marlin Smoot
Member From: Atlanta,Georgia, USA
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posted 14 March 2006 12:13 PM
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I found the best way to stop the 60 cycle hum in a Tele or Strat: install a set of Kinman pickups in your guitar tele/strat. Check out the kinman website. He talks about this issue and there are sound bits you can listen to.
Good luck in your quest for tone. |
Brint Hannay
Member From: Maryland, USA
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posted 16 March 2006 08:46 AM
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It seems that much of the discussion in this thread has dealt with Teles and Strats. I find hum most bothersome in the case of steel, because of the use of the volume pedal. When playing slow tunes, when you're trying to sound the sweetest, sustaining long notes/chords by using the volume pedal gradually fades in hum as the string's vibration dies away, and the signal-to-noise ratio can become intolerable! The good news is that a number of the humbucking pickups being made for steel these days sound very, very good, IMHO. |
Dave Mudgett
Member From: Central Pennsylvania, USA
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posted 16 March 2006 10:02 AM
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quote:
I find hum most bothersome in the case of steel, because of the use of the volume pedal.
I use a volume pedal on guitar also, and that's not the only reason the noise problem is worse on steel. The other reason is that you hold the guitar close to your body, and can use your body as an EFI shield. In conjunction with the string ground, this often gives effective noise reduction. This doesn't work anywhere near as well on steel. Of course, one can put a noise-bucking pickup into a guitar. But the question of this thread is - what can be done to reduce noise while retaining the single coil. Especially in a vintage steel, most people don't want to go monkeying around with the pickups, either because they like the tone or because they don't want to devalue the instrument by modifying it. With vintage values the way they are, nobody in their right mind would take a stock, clean 50s or 60s Strat or Tele and add a humbucker. I think this is headed that way with old steels like Bigsbys, old Buds, and old P/P Emmons. |
David Spangler
Member From: Kerrville, TX USA
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posted 16 March 2006 08:40 PM
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Another approach is to install a preamp near the pickup which converts the output to low impedance, change the pots to 50K and end up with a rig similar to how EMG treats their single-coil pickups. Such a preamp is available from:
http://store.guitarfetish.com/acpicokimibo.html ------------------
David Spangler[This message was edited by David Spangler on 16 March 2006 at 08:44 PM.] [This message was edited by David Spangler on 16 March 2006 at 08:45 PM.] |
Larry Hamilton
Member From: Amarillo, Texas, USA
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posted 18 March 2006 06:13 PM
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The Star Steel Guitar has a single coil PU that is as quiet as a humbucker. they are really something and they sound great. I heard them in Dallas and at a friend's house. Albert Talley would probably make you buy the whole guitar to get the PU, HA-HA  ------------------
Keep pickin', Larry |
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