Wishbringer Music

 

Dealing With Hum and Noise

 

 

IDENTIFYING THE SOURCE OF GUITAR NOISE AND HUM 

 

Wishbringer produces a noiseless pickup known as the FlatCat™.  We have sold a lot of them, to highly-satisfied 5-star customer reviews.  The reason for that is its internal design and circuitry, which not only produces a unique, wonderful tone but also produces no internal noise or hum.

 

Each FlatCat is hand-tested prior to shipping to insure there are no noise and hum issues. So if you've recently purchased a FlatCat you can rest assured it has already been tested for precisely these issues, and passed all tests. If you're experiencing noise, the problem is not the FlatCat.  Time to dig in and find the true source of your hum or noise.

 

Consider:  If your automobile engine stops running you don't blame the tires. Unless a pickup is old and broken, noise problems are pretty much always external to the pickup (if the pickup is a noise-free model such as the FlatCat).


ELIMINATING MISCONCEPTIONS

It is a wide misconception that humbuckers stop all noise.  This simply is not true.  A humbucker is designed to stop internal hum that can be caused by a single coil.  Humbuckers double and reverse the coils, countering internal hum.  But no pickup can stop all sources of noise that can interfere with a guitar.  


Wikipedia states regarding humbucker pickups: "Compared to single-coil pickups, especially unshielded ones, humbuckers dramatically reduce hum."

 

Note that they specifically compare humbuckers with single coil pickups... not a humbucker vs all noise sources in the world.  Even then, they state that humbuckers "dramatically reduce hum"... not eliminate it.  If they only reduce hum caused by single-core pickups... imagine what a pickup has to deal with in the case of far stronger external noise sources.

 

A quality amplifier can hum even when a guitar isn't plugged in.  This demonstrates the core problem with noise issues. There is a difference between internal pickup noise (caused by a single coil) and mains hum, caused by external sources such as poor electrical feed, improper grounding, RFI and EMI. Expecting a pickup to totally eliminate all noise sources is like expecting an automobile to avoid all car accidents.  A noise-resistant pickup can make a big difference... but is not a magical cure for all possible sources of electrical interference.

 

Not a "Humbucker"

Some buyers refer to the FlatCat as a humbucker because of the fact that it's a noiseless pickup (and in their experience, only humbuckers do that).  However it is apparent from the size and shape that a FlatCat is built differently than a humbucker.  A humbucker is a specific design of pickup.  FlatCats on the other hand are totally unique in design and circuitry.

 

Like a humbucker, the FlatCat produces no hum or noise and can even help combat external noise as much as is physically possible without distorting sound.  Because of its unique design the FlatCat kills hum as well as a humbucker, but its output is true to the sound of the instrument, providing the warm, rich tone for which the FlatCat is known. (Humbuckers are known for often having a "harsh" overtone... adding a bit of distortion to the instrument sound.)

 

A humbucker typically uses small pins or thin dual rails that detect a small portion of the vibrating string.  Conversely, almost the entire surface of the FlatCat is active, picking up a far greater length of the string, both primary and even subtle sub-harmonics, thus producing a richer, more vibrant tone.  In short, the FlatCat is a totally different species. Wishbringer pickups are quite a bit different... which is what makes them special. 

 

The FlatCat is inexpensive for a hand-made, custom pickup.  It is potted in solid polyurethane and pretty much never breaks down because the internals are sealed from air and resulting oxydation.  A FlatCat can perform flawlessly for decades.

 

That's the intro information.  Those things understood, we can now get down to...


 

THE FACTS ABOUT NOISE AND HUM
Unprotected single-coil pickups are known to create hum/noise of themselves.  Guitar enthusiasts still use these pickups because of their unique sound.  A very famous guitar that commonly uses single coil pickups is the Fender Stratocaster SSS.

 

In the case of other pickups however, hum and noise almost never sources at the pickup (unless the pickup is broken).  Noise comes from other sources.

 

There is no pickup in the world that can eliminate all sources of noise. That's simply not what a pickup is designed to do. Realizing that fact is the first step to locating and ending your hum/noise problems. It is good to understand the source of hum... and the steps needed to totally eliminate it.  

 

There is an interesting starter article entitled MAINS HUM on Wikipedia.  While fairly complex in places, it presents some enlightening information:

 

https://en.wikipedia.org/wiki/Mains_hum

 

Notice in at least two places in the article it indicates that humbuckers are designed to "reduce hum"... not eliminate it. The article also notes that too great an effort at removing hum with a pickup can actually distort and change sound (as already mentioned).

 

Note too that these pickups are called humbuckers, not noisebusters.  Hum and noise are two different things, with different causes.

 

So there's only so much any pickup can do to eliminate hum. That's really not the pickup's job.  Ideally the job of the pickup is to reproduce the guitar's sound as faithfully as possible without adding hum or noise of its own.  That is what the FlatCat does:  it produces wonderful, clear tone, noiselessly.  In some cases the design of the pickup can help reduce certain types of external hum.  Many players notice that when they attach a FlatCat to their guitar, prior hum vanishes completely.  That is the ideal situation, but is not always the case. 

 

Some sources of hum and noise are simply too strong for any pickup to handle.  If noise persists, it's time to go hum-hunting.  

 

GROUND LOOP and OTHER SOURCES OF NOISE.  The above Wikipedia article discusses primarily ground-loop hum, which is only part of the problem (but often the prominent part).  Other issues are RFI/EMI  created by electrical devices or shorts.  Proper shielding and/or quality twisted pair or shielded wire may be an answer to that.  RFI/EMI impulse is best sent to ground... which brings us back to ground loop issues.  If the ground loop is bad, it's all bad.


PRO NOISE KILLERS vs UNINTERRUPTED POWER SUPPLIES
Even the finest pickups cannot provide total proof against hum. This issue is why the Hum-X device exists (as well as other anti-noise devices).  Professional musicians often use rather expensive equipment to eliminate noise.

 

Uninterrupted Power Supply.  A UPS device or voltage regulator is less expensive and can serve the same purpose.  UPS isolates your equipment from wall-direct AC current by running it through a DC battery, then converting it back to AC for your amp... hopefully eliminating ground loop issues entirely (if the UPS itself is working properly).

 

I recommend UPS devices for ALL important electrical equipment (music equipment, televisions, computers, etc).  They are no more expensive than a quality surge protector... and work far better.  Several options and power levels are available at a wide range of prices.  Choose the one that's best for your power needs.

 

Of course a UPS is not a magic solution to all noise.  But grounding issues are the easiest and first thing to check, and can be relatively easy to overcome, unless the grounding issue is within your equipment itself.


RADIO FREQUENCY INTERFERENCE
RFI is all around us to varying degrees.  It is so widespread and so complex that there are entire BOOKS written about how to handle RFI issues. Professional techs fight RFI regularly, so it is obvious that preventing RFI noise on your guitar can be quite an issue.  Fortunately, there are solutions.

 

Interestingly, the strings themselves act as antennae and can absorb RFI (to an extent)... if the strings are grounded. If your strings aren't grounded, they can actually attract RFI to your guitar electronics.

 

Some pickups such as the Gibson Classic humbucker are completely covered in a metal cover (grounded) to block RFI at the surface. That works fine above the pickup, but what about underneath?  Quality electric guitars have the cavities lined with copper or aluminum tape to stop RFI.  Internal wiring may be twisted-pair or shielded to prevent RFI.  (The FlatCat uses twisted-pair, data-certified wiring.)

 

RFI can be difficult to detect, and is usually a bit more time-consuming to correct. Sources of RFI are computers, televisions, other digital devices... or living near an RFI source such as a TV or radio station.  RFI sources are many and varied.

 

Quality guitars are totally shielded against RFI (which is partly why they cost more). If you open your guitar and the cavities are bare wood without shielding tape... well, that reduces the cost of production but it doesn't do much to stop RFI.

 

FlatCat pickups use internal circuitry and twisted-pair data-certified wiring to shield against RFI. But you may need to take other steps against heavy RFI.  There's only so much a lone pickup can do.  One user completely wrapped his FlatCat with copper tape to prevent severe local RFI issues.  When it comes to fighting noise and hum, you do what you have to do. 


ELECTROMAGNETIC INTERFERENCE
If you have proper grounding and have eliminated RFI problems that leaves EMI... and  EMI is just the worst.  There are limited methods to solving severe EMI problems.  I know of no "magic cure" for all EMI (though there are some devices and methods that can greatly reduce the effects of EMI). 

 

Interestingly, your amp itself can be a major source of EMI, as it actually works by means of a considerably powerful electromagnet that's part of the speaker.

 

Usually the first step in eliminating EMI is to try moving your equipment.  Sometimes shifting amplifier or guitar direction, or moving it just a foot or two will suffice to get out of the offending magnetic field.  

 

Don't get your guitar too close to your amp (most players already know this).  Don't have your amp facing your guitar (feeeedbaaaack).  If you are in a strong EMI area, you may need to shut external equipment off or even move to another room or practice area.

 

 

PRO AUDIO MAGAZINE states: "EMI can plague your guitar as well as your other audio equipment, causing a particular buzz or hum that can sometimes be impossible to get rid of depending on the source." 

 

See that word "impossible"?  Believe it. The way to eliminate EMI is to eliminate the source, one way or another. The article continues:

 

"You should also be aware that it’s not just pickups that are susceptible to EMI. The wiring on a guitar can be also be affected. If that’s the case, you should definitely look into shielding your guitar wiring."  

 

So if the pickup itself does not produce hum (the FlatCat does not; in fact it can significantly reduce hum)... the source of noise / hum / buzz  may be the guitar itself (unshielded or faulty parts), the guitar cord, your amp, or external equipment. Try putting your guitar next to an electric blender sometime. The effect can be... interesting.


WHAT DOES THE PICKUP ACTUALLY DO?
Noiseless pickups (including humbuckers) can REDUCE EMI to an extent. That's how they're designed. But there's only so much a small pickup can do against the EMI MONSTER.  No pickup can completely eliminate EMI if the field is strong enough.  You already keep your guitar a reasonable distance away from your amp to eliminate feedback.  In like manner, you keep your guitar and other equipment away from EMI sources.  


TESTING FOR NOISE

 

* WIRE SWITCH.  This may sound simple, but the first thing you might do is simply try reversing your pickup wires, switching where they're connected (hot + / ground -).  Sometimes noise (or low volume) is caused simply by the ground and hot wires being connected backwards.  You may be surprised how often this is the case. You should be able to audibly tell the difference and determine the proper wire connection.

 

* TEST NOISE LEVELS.  Plug in your guitar.  Ignore any noise or hum. Strum a few chords and notes to see if the sound is normal, acceptable sound without excessive noise.   If you have excessive noise that can be heard even when playing, you have a problem.  Quality instruments when played should pretty much override any noticeable hum.   That's the purpose here: to make sure there's no excessive source of noise that might indicate more serious problems than basic hum

 

Contrary to popular belief, most instruments and amps exhibit a small degree of hum.  This is not unusual at all.  While it may be possible to eliminate even that small amount of hum, you should not be surprised that some hum exists. Many professional musicians just accept that fact and get on with it. 

 

 

* TOUCH TEST #1.  Turn on your amp, turn the volume to normal playing volume.  The GAIN should be minimal (Gain tends to cause noise).  Bass, mid and treble should be set to mid-range or lower (on most amps a setting of 3-5 is considered good testing range).  Without the guitar plugged in, touch the bare end of the guitar cord to make sure you have continuity and that it doesn't "roar" (too much power from the amp).  You just want a mild sound when the end is touched.  (Of course the other end of the cord must be plugged into the amp.)  This simply tests the degree of potential noise.  A loud irritating sound may indicate potential loud hum or noise.

 

* TOUCH TEST #2. Hook up your guitar to your amp. Quiet the guitar strings (mute with your fingers).  When the guitar is quiet, remove your hand from the strings.  If hum appears there's definitely a grounding problem.  Your hand and body acts as ground.  When you remove your hand and hum appears, you have cancelled ground and proved your guitar or other equipment has a grounding issue.

 

* TOUCH TEST #3. Touch the metal sleeve of your guitar cord.  If the hum vanishes when you touch the metal sleeve, there is a ground loop issue that will need to be corrected. If there is still hum when you touch the sleeve, that is indication the hum is internal to the instrument.  The instrument itself should be checked for proper internal grounding (pickup grounded, bridge, strings, and controls grounded).  Check for short circuits (wires touching one another or connected to the wrong pins). 

 

* CHECK FOR WALL GROUNDING. If you have a 3-prong LED outlet ground tester, use it to make sure the outlet is properly grounded.  Regardless of the results (even if it shows proper grounding), if your amp has a 3-prong cord... turn it off, unplug it and plug the cord into a 2-prong wall adapter (available cheap, anywhere).  Plug the adapter in and turn the amp on.  If the hum vanishes-- the problem is definitely a wall-based ground-loop issue, no matter what testers show.  A tester can show a grounded outlet and the power still be "noisy" or bad.   

 

Whether there is hum or not, after a few seconds turn the amp off and remove the adapter.  A 3-prong amp should not be operated for any length of time using a 2-prong adapter (even if the hum vanishes).   But hum vanishing when using a 2-prong adapter definitely identifies one cause of the hum:  the source of your electricity.


IF ALL ELSE FAILS... THE ALUMINUM TEST

This test sounds strange, but it is a test only.  Wrap the entire body of your guitar with aluminum foil and make sure the foil connects with the cord jack sleeve (for grounding).  If the hum disappears, the problem is very likely RF interference.  Then un-ground the aluminum foil from the cord and see if the hum returns. It may or may not, depending on a number of variables.  But if you verify the RFI, you've located a noise source.  

 

Then you can remove the aluminum foil.  It blocked all RFI and did its job.  This is basically a "let's see what happens" test to check for significant external interference. 

 

Of course you can't play an instrument wrapped in aluminum foil-- but it will let you know if the problem is a lack of shielding and may identify that at least part of the issue is RFI.  Once you have done that you can remove the foil and work on making your guitar proof against RFI.

 

* Note that the aluminum foil test WILL NOT check against EMI.  In fact aluminum is a great transmitter of magnetic fields, as are many metals. Some pickups are actually made with an aluminum core for this very reason (the LACE pickup is one such example).  EMI is a totally different beast and as mentioned before, must be handled differently.


AN EXTREME SOLUTION THAT WORKED
If you search the Internet you will perhaps come across this solution:  Several guitar players have built FARADAY CAGES to house their amplifiers. (If you don't know what a Faraday Cage is, check the Net.)  While this sounds like an extreme, in their case it worked.  And if it works... bingo.

 

What this demonstrates is that sometimes noise sources can be very difficult to control and may require heavy measures. (Remember the magazine article said "impossible".)  If your environment requires placing a Faraday Cage around your amp... so be it.  Sometimes reality really bites... and different environments have different problems.


SUMMARY

The three primary sources of noise and hum are Ground Loop (or grounding), RFI and EMI... and each problem is handled differently.

 

There is no guitar pickup that can totally eliminate all three problems.  This is why (sometimes pricey) anti-hum / anti-noise devices exist on the market.  Even those devices cannot guarantee to handle all noise problems... but some of them work really well. It may be that all you need is a UPS device or voltage regulator to filter your eletricity.

 

Unless the pickup is an unprotected single coil, worn out or actually broken... hum is pretty much always external to the guitar pickup.  People will often claim the pickup is faulty... but that's because noise problems are so prevalent and the pickup is easy to blame. But the pickup is working fine and most likely is helping reduce even worse hum.  Replacing a functional pickup will not locate or stop your noise issues.

 

LOCATING THE ACTUAL SOURCE of hum can be a time-consuming process, and there are sometimes no quick-fixes.  The key is to find the actual source of noise problems as shown above, and attack noise at the source.  In addition there are many videos on YouTube as well as Internet articles that will help you locate and correct severe noise problems.

 

-- Wishbringer Traditional Music

 

 

ADDENDUMS

 


An almost humorous note:  One customer contacted us with a video showing him holding his brand new FlatCat pickup connected directly to a guitar jack, both of which he was suspending in the middle of the air... and he was experiencing significant noise.  He claimed this proved the pickup was definitely the problem.

 

My answer to him:  "I'm not surprised there's significant noise.  You've taken no steps to protect your pickup from every source of noise around you.  You're dangling it in the middle of the air without guitar shielding, strings to absorb RFI, any protection against external EMI, and if your guitar cord or jack is bad you may be even have grounding issues.  I would almost guarantee some kind of noise in such a situation."

 

His saddened answer was, "Oh. Now I wish I hadn't mailed it back to you."  Sigh. 

 

The moral of the story:  Don't blame the pickup.  Look for the source of the noise.  There's only so much any pickup can overcome

 

A head-banger tale:  One customer contacted me stating that he was experiencing severe noise with the FlatCat that he hadn't had with his prior pickup.  Of course it was natural for him to suspect the FlatCat, but I knew it had been tested prior to shipping.  So we examined many things on his guitar (the customer was thankfully cooperative) and finally, through the process of elimination, I recommended he try replacing the cord jack on his guitar.  The customer did so... and his noise vanished completely.  Evidently somehow while switching out pickups the jack had become damaged and created a grounding problem. Replacing the jack fixed that problem.  That was not an easy problem to find, but we stuck with it and located the source of the problem.

 

The moral of this story: Noise can come from the most unexpected places. Even when it seems absolutely certain that the pickup is to blame... it is most likely something else causing the problem.

 

In over nine years of selling FlatCats, we've never found a case in which the source of noise problems was the pickup.  It has always been other factors-- things that we were able to help hunt down and the customer was able to fix.  The FlatCat is a very reliable guitar pickup.  This page was created to help you hunt down such issues, for they are many and have big teeth. 

 

 

 

THE PURPOSE OF A FLATCAT PICKUP
1. Provide as much power and accurate tone as possible without distorting the sound. Any desired sound alteration can be done with pedals and amplifier.  

 

2. Provide sound reproduction that is true to the sound of the instrument (example:  hollow body should sound different than solid body)

 

3. Dramatically reduce noise, hiss and hum... to the extent possible.

 

4. Balance all the strings so the end result is a harmonious tone

 

The FlatCat succeeds on all levels. Overwhelming 5-star reviews from satisfied customers prove it works very well and produces very satisfying sound-- especially from a device that is only 1/4" thick.


ADDITIONAL SUGGESTIONS FOR TRACKING DOWN AND FIXING HUM

 

Detecting RFI sources using FM radio bands: 

https://www.youtube.com/watch?v=0_919kOA45U

 

RFI & Ferrite Coils:  https://www.youtube.com/watch?v=LuMlM8zWQFk

 

Regarding Wall Transformers:  If any of your equipment uses "wall wart" transformers, be sure to use LINEAR (heavy) transformers rather than DIGITAL (light weight) units. Digital units can create RFI and be more prone to grounding issues. 

 

Triple-check all grounding issues... within the guitar itself, your guitar cord (especially the guitar cord, which wears out over time and can cause severe hum and noise), your amplifier, your power cord, the wall plug itself, and ALL intermediate equipment.  

 

Ground loops and RFI / EMI are the primary causes of guitar hum and noise, even with "humbucker" pickups.  As seen above, all a humbucker does is help reduce some types of hum.  Total noise elimination is simply not the pickup's job.  That task falls to the musician or sound techs.

 

There are simply too many kinds of hum and noise for any one device to counter. The trick is to first locate the source of noise or hum... then take steps to counter it.  Those steps may include:

* Repairing ungrounded wall outlets
* Purchasing and using an Uninterruptable Power Supply
* Foil-lining your guitar and internal wires
* Re-soldering all internal guitar connections
* Replacing worn-out controls (volume / tone pots)
* Replacing old guitar cords
* Sometimes even replacing a worn-out amplifier

... etc etc.  

 

Again, the sources of noise are many.  Finding the source and countering it is part of the proper maintenance of your electric guitar.

 

 

WISHBRINGER TRADITIONAL MUSIC offers 100% post-sale support.  If you are experiencing problems, feel free to contact us for FREE consultation. I enjoy helping my customers reach their goal of achieving the warm, rich sound only a FlatCat can provide.