A box that eliminates all hum and noise

Keith Hilton · From: 248 Laurel Road Ozark, Missouri 65721

I recently had a ground loop noise while practicing my steel guitar. I pulled out a circuit I built a couple of years ago, plugged it in and everything was dead quiet. I thought how this could help a lot of people. I started looking at hum and noise devices for sale on Sweetwater, Reverb, Amazon, eBay, ETC. I came across what seemed to be the most popular, best selling of the hum and noise elimination devices. This device was advertised as--not being a noise gate. What blew me away was the claim that it could eliminate hum in every pickup, no matter of what type of pickup you were using. To me that means it could eliminate single coil pickup hum and noise. I suppose from the advertising it could eliminate all noise coming from an amplifier needing repair. It could eliminate all bad guitar cords, making them like new. It was interesting to me to notice this particular product was the biggest seller, and it was made in China.
Eliminating all noise and hum is a tall order, because of the many sources of noise and hum. The biggest cause of hum is ground loops. The next biggest cause of hum is single coil pickups. Then you have grounding problems, magnetic interference, radio frequency interference, defective equipment and the list goes on and on.
I looked at the best selling hum/ noise elimination box and noticed it had one switch. Normal hum and real bad hum. I started thinking about what the circuit had to be like in this best selling noise/ hum elimination box. First off-- I guessed it had a isolation transformer to eliminate ground loops. But I wondered if the isolation transformer colored the tone? Secondly--To eliminate hum in single coil pickups, the noise/ hum elimination box would have to have a dummy coil. The dummy coil with the winding in magnetic reverse, and the magnetic polarity in reverse of the signal coil it was transforming to no hum. Not knowing what direction the wire turns are on the the magnet in a guitar, or the magnetic polarity of the pickup---How could you possibly create a humbucking situation with "ONE" switch. All one switch would do is make the signal out of phase. So here is what I am guessing the one switch does. The switch that goes from normal hum to real bad hum. I am guessing the real bad hum switched on, switches the circuit to a 60 cycle notch filter. A 60 cycle notch filter is simple to make, and cuts out the 60 cycle frequency in your sound. Trust me, when that frequency is cut out it sounds terrible.
So what am I getting at here? If I make a noise, hum, elimination device and sell it, I would not feel right using false advertising to sell it. How could anyone selling a hum, noise elimination device feel truthful saying it totally eliminates all noise and hum? The company selling these devices is here in the United States, but the boxes are made in China. I guarantee you this much--If I make a noise and hum elimination box there will be no lies and no exaggeration---I will explain what it will and will not do. I am certain it will not be a big seller, because how could anyone compete with something that eliminates all noise and hum. Think about it, and think about the advertising!

Keith Hilton · From: 248 Laurel Road Ozark, Missouri 65721

I went on Sweetwater and looked at the reviews of the largest selling hum, noise eliminator, mentioned in the above post. 56% of the reviews gave it a 5 star. 15% gave it a one star or less. 28% were middle of the road. Almost all said it colored the tone terribly, almost to the point of not being usable. Probably the ones who did not care about tone were the rock and roll guys using high distortion, where tone does not seem to matter as much as other forms of music. To me it looks like the best selling hum and noise eliminator has a really high return after purchase ratio. To get rid of hum in single coil pickups the box mentioned has to be some type of notch filter, mixed with other components. Trust me those notch filters sound horrible and I don't see how they could be used in Country Music.
As I read the advertising for the different hum and noise eliminators, it reminded me of the snake oil salesmen of old. A bottle would cure anything from cancer to ingrown toe nails. It also reminded me of the face cream I see for wrinkled women ages 60 to 80. For $69.00 you can buy this face cream that will eliminate wrinkles that took 80 years to get there. Made me wonder what ever happened to Carter's Little Liver pills. As I remember they were supposed to cure a large number of health related problems. What happened to being straight forward and honest? I guess honesty in advertising is old fashioned nowadays.

Bob Sykes · From: North Carolina

Bruce Derr · From: Lee, New Hampshire, USA

Sounds like you're referring to the EHX Hum Debugger. A friend of mine has one and has found it useful in noisy clubs. He's not a rock musician using distortion, but a terrific steel player with very good ears and very high standards for tone.

Looking at the company's description, this device obtains a reference hum signal from the power supply. The AC power supply that comes with the unit is a necessary component for the device to function correctly. I don't know if the reference signal is just what comes from the transformer secondary or if there's an additional hum antenna wire in the power supply cable. In any case, in the Normal mode, the device filters the odd harmonics of the reference signal, and all harmonics in the Strong mode. I don't think it's a simple analog notch or comb filter. Yes, the filtering is audible, especially in the Strong mode, from what I've heard and read. Not ideal, but lots of reviewers seem to prefer that over enduring the hum. I've never tried the unit myself, so I have no personal opinion of it, negative or otherwise. This box was not yet available back when I was a single-coil die-hard, but if it had been, I would have definitely had one handy to use when needed.

All that being said, hum is a mysterious problem to many musicians, so I expect some folks to have too-high expectations from this device, especially with the somewhat grand marketing prose presented by the company. As I understand it, it's designed to reduce hum from an instrument pickup. It's not going to fix a bad cable or a noisy amp. But I don't consider their claims to be at "snake oil" level.

Donny Hinson · From: Glen Burnie, Md. U.S.A.

Dumb question, possibly unrelated, but has anyone ever done studies to find out exactly why a humbucker doesn't sound like (read: "as good as") a single-coil pickup? Is it the higher inductance, internal capacitance, or resistance? Eddy currents?

Bruce Derr · From: Lee, New Hampshire, USA

I don't think it's a dumb question. I'm no pickup expert, but from what I've read over the years, the factors you mentioned play a part, and also the wider "aperture" of the pickup, because it's sensing a longer portion of the string than a single coil would. Maybe a stacked humbucker with buffered coils would address the effects of both the wider aperture and the heavier windings.

Keith Hilton · From: 248 Laurel Road Ozark, Missouri 65721

Great question Donny. Donny your question relates to a question that has always been in my mind. How can two magnetic pickups wound in opposite direction, and having opposite polarity eliminate common mode noise? I have never heard anyone try to explain it, and I would like to know why common mode noise is eliminated. I hesitate to build any type of noise/hum reduction box, because of the countless reasons for noise/hum. At this point I am not even sure if I could build something that would cure most ground loops issues. The economics would say, why build any noise/hum device if the return rate was 50% or even 30%. How could you feel good knowing your advertising was 50% or 30% wrong. If the description of the device said, "This device may alter your tone", how many do you think would sell? Donny, as many wrinkle's as we have, maybe we need to order some of that wrinkle cream and try it. As ugly as I am it could not hurt anything.

Jeff Highland · From: New South Wales, Australia

https://www.stewmac.com/video-and-ideas/online-resources/learn-about-guitar-pickups-and-electronics-and-wiring/understanding-guitar-wiring-part-1-how-a-magnetic-pickup-works/

Whilst the term Humbucking is typically applied to gibson style pickups there are other designs which achieve hum cancellation without the loss of highs, such as the valco string through pickup which has two coils but each only picking up signal from 3 strings. Also P bass, G&L Z pickup. Duesenberg domino etc
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David Ball · From: North Carolina High Country

The HumDebugger works wonders on 60 cycle and it's cousins' hum. In return though, it creates a little gap at certain frequencies that are harmonics of 60 cycle. A bit of attenuation. Very narrow gap though, and easily overcome. If you're working in a place with neon lights, AC wiring under the floor etc. where the hum can be really noisy on single coils, it can work wonders though. Not perfect, but danged good.

I guess the only box that eliminates all hum and noise is an acoustic guitar!

Dave

Jerry Overstreet · From: Louisville Ky

Keith Hilton...your mind must always be working to come up with ideas like these. Many valuable and usuable player friendly tools and gadgets as a result.

David's post reminds me that my Boss SE70 has a program named Hum Canceller that indeed kills all 60 cycle hum...I believe it can be tweaked for a 50 cycle freq. as well. This is all done through the unit's Noise Suppressor algorithm which is basically the same as Boss' NS stomp box.

Similar to what David wrote, it does affect the tone. In my case, I run a couple Boss and Roland units in series so I can cure that tone change through the GP100.

I've forgotten how it affects tone, good, bad or otherwise, but I do remember it's noticeably altered.

I wish I could report the basics of the algorithm, but all I see besides the NS effects patch is frequency and threshold as parameters.

Fred · From: Amesbury, MA

Jack Hanson · From: San Luis Valley, USA

As one who prefers single-coil pickups for most of my instruments in most situations, I've found the EH Hum DeBugger to be somewhat useful in rooms where there's dirty power, and/or severe 60-cycle noise. It sometimes adds weird artifacts to the sound, but does reduce and often eliminates the annoying hum altogether.

I've discovered the most effective box for noise reduction in single-coils is "Faraday's Box" (aka Faraday Cage or Faraday Shield). By enclosing all electrical components in their cavities surrounded by a combo platter of conductive shielding paint and shielding foil, those pesky single-coils are quiet as a church mouse in most situations.

The extra shielding will also help reduce -- but not totally eliminate -- the interference caused by neon and fluorescent lighting, transformers, etc. In severe cases, a Hum Debugger may still be necessary. It's a trade-off: What's more annoying -- the constant hum, or those intermittent, unpredictable, weird artifacts?

David Laveau · From: Rocky Mountain High, CO

Dave Campbell · From: Nova Scotia, Canada

i went on a tour and took and emmons s10 with a single coil. almost all the stops on tour were fine, but one club (and iffy soundman) left me with a crippling hum. i busted out the hum debugger and set it at the lowest setting. it definitely was not ideal tonewise, but it made an unbearable situation bearable.

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