Guitar Wiring - Tame Static Noise and Hum with Foil Shielding

Started by shawnb, August 16, 2012, 01:15:49 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

shawnb



All -

A friend had an old '78 Rickenbacker 420 with damaged electronics (wires pulled due to loose jack).  He asked me if I'd try to solder it back up, since I've done some electronics work before.   I've never rewired a guitar before, but I figured it'd be a breeze & a fun learning exercise...  How hard could it be?

The initial pickup had been replaced with a DiMarzio humbucker, and the wiring was nuts.  The tone knob was not wired with a capacitor, it was wired essentially as a vol pot for one of the two coils.  So...  Vol was vol, but Tone must have moved it from double-coil to single coil?   I believe that was the intent.   

I got an Orange 22 cap, rewired the whole thing per DiMarzio specs.  Vol worked, tone didn't - I found out the tone pot was busted internally. 

Pulled it all out, bought two new pots, started over.  Couldn't make up my mind serial vs parallel with the humbucker, so put in a little switch so it would go either way (per the attached).   

Tested it all up, and it all works perfectly.   But now I have clear RF noise.   It goes away when I put my hand on the strings. 

I've been reading up a lot on noise, & a lot of it contradicts.  Couple of specific questions:
  • The cavity is NOT shielded.  Should I do so?   I've read mixed things about whether this makes a difference with a humbucker. 
  • The faceplate is shielded, then painted.   I also connected my pots' casings together & to ground.   Is it possible my faceplate is creating a ground loop?   Would that increase noise?  Faceplate is slightly damaged, so I'm not sure if the pots' casings are connected that way or not.
  • I have a couple of my grounds connected to my vol pot (bridge & vol) & a couple to my tone pot (pickup & cap).  I JUST NOW read somewhere you should have all internal groundings connected to your vol pot casing, then one single connection to tone pot casing & one from tone casing to line out.   If this is true then I definitely need to move my pickup & cap grounds over to the vol casing.   To me, this doesn't feel logical/necessary.  Is it?
I fear I may need to undo all grounding & redo it carefully & slowly...   Picture of my first guitar wiring job is attached, though this is BEFORE I cleaned up the flux, etc. 

The little single switch for serial vs parallel is simple & nice!  Overall, the guitar sounds GREAT!!!!   Until I remove my hands from the strings...

Shawn

DiMarzio wiring doc that describes the serial/parallel switch:
http://www.google.com/url?sa=t&rct=j&q=dimarzio%20pickup%20wiring&source=web&cd=2&cad=rja&ved=0CEoQFjAB&url=http%3A%2F%2Fwww.dimarzio.com%2Fsites%2Fdefault%2Ffiles%2Fdiagrams%2F4Conductor.pdf&ei=pEwtULODKqOxywHqt4GwDQ&usg=AFQjCNHrYFJrHimBJ2ziTfHyCEf4LHqang
Address the process rather than the outcome.  Then, the outcome becomes more likely.   - Fripp

Elantric


gumtown

All your grounding needs to be at one point only, i would move all the ground connections (and the orange cap ground) to the back of the volume pot to create one single star point for grounding.
If you are getting noise from removing your hand from the strings, there maybe a problem with the grounding of the bridge (which also grounds the strings), or a problem with grounding on your amp where your body capacitance is creating a grounding point.
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

concordal

shawnb, in my experience most of what you describe can be eliminated with meticulous shielding.

The gory details are explained step-by-step at http://www.guitarnuts.com/wiring/shielding/shield3.php.  The example illustrated there is for a Strat, but the principles are universal. 

I didn't think that shielding paint or aluminum foil shields were up to the task.  So in my case I used a laser cut copper shield for the pickguard from http://www.monteallums.com/shielding_supplies.html.  He also stocks copper foil so you can cut your own custom shape.  For the pickguard cavities I used special copper tape with conductive adhesive backing from Stewart Macdonald - http://www.stewmac.com/shop/Electronics,_pickups/Supplies:_Shielding/Conductive_Copper_Tape.html?actn=100101&xst=3&xsr=991.

The guitarnuts site referenced above has some interesting detail to explain why soldering a bonding wire onto the backs of guitar pots should NOT be done because it can create a ground loop.  He does recommend a single point of grounding but some of the joins are isolated by a capacitor.

It was a fair bit of work, but for me, well worth the effort --  my single coil Strat has almost no noise.

Hope this is helpful.

Elantric

QuoteI didn't think that shielding paint or aluminum foil shields were up to the task


Actually I find internal Ground Loops not to be much a problem or as big a source of noise with my internal guitar wiring.
But i do always find another type of noise on MANY New guitars that have the controls mounted on a"plastic pickguard" that MUST be tamed in only one manner -  Foil shielding applied to the complete underside of the pick guard is mandatory - particularly directly under the areas of the pick guard where you strum. Its not to eliminate "hum", instead its required to tame a "rice crispy" static build up / discharge noise effect that is a result of electrostatic charge build up on the plastic pickguard material. If you do not have this type of a foil shield applied directly under the pick guard areas where you strum, you will be doomed to always hearing a brief slight "crunchy / static" noise in your audio stream -  coinciding with each strum of your right hand as it traverses the top of the pickguard while struming.


Lately i use a Glue stick and Aluminum foil applied to the underside of the ENTIRE pick guard - more foil than simply confined to the typical electronic cavity area on all my guitars.

http://www.amazon.com/UHU-Glue-Stick/dp/B001HTKBLQ/ref=sr_1_7?ie=UTF8&qid=1345152845&sr=8-7&keywords=uhu+glue+stick






No need to solder a ground connection to the Aluminum Foil - just re-mount the Pots and switches to the pick guard and tighten the nuts, and this insures an electrical Earth  Ground connection is accomplished.


     

shawnb

Thanks guys - so a confirmation on moving all grounds back to the vol casing (thanks gumtown!), and a confirmation to go ahead & line the cavity even though it's a humbucker (thanks concordal!). 

I've been thru all of these websites before.  They tell you TO ground, but some of these finer details on HOW TO ground are either unspecified or are contradicted on other sites.   

Thus the confirmation from the veterans here is welcome!   

Fig 4 on the guitarnuts site is the very one that made me concerned whether the faceplate may be causing a ground loop.   I think I could test this tonight with a meter fairly easily if I disconnect the ground wires between the casings - if the vol casing remains grounded, then the faceplate ground loop is verified & I should act accordingly.   

(Elantric - I think concordal is specifically answering those folks out there that recommend household aluminum foil for shielding the cavity:   http://www.diyguitarmods.com/telecaster-foil-shielding.php

Note that this Rickenbacker's faceplate is shielded, but the cavity is not.) 
Address the process rather than the outcome.  Then, the outcome becomes more likely.   - Fripp

aliensporebomb

Elantric:  I've been curious: do you know of the Roland Ready strats come with extra shielding as supplied or are they pretty much like any other strat out of the box?  I wondered this given the extra electronics inside.
My music projects online at http://www.aliensporebomb.com/

GK Devices:  Roland VG-99, Boss GP-10, Boss SY-1000.

Elantric

QuoteI've been curious: do you know of the Roland Ready strats come with extra shielding as supplied or are they pretty much like any other strat out of the box? 

Depends on the year of Manufacture



aliensporebomb

Quote from: Elantric on August 16, 2012, 03:00:45 PM
Depends on the year of Manufacture

regardless - I always advocate adding more foil shielding under the pickguard to those areas where none is currently present

Would early manufacture be preferable or later?

Regardless, next time I restring I'll take a peek under the guard and visit the kitchen for some reynolds wrap if necessary!  From what I can hear, the GK side is pretty quiet.  But it might be quieter.  The electric guitar side - tonally I love the way it sounds but single coils always sound noisier than they should.  I'll take pictures.
My music projects online at http://www.aliensporebomb.com/

GK Devices:  Roland VG-99, Boss GP-10, Boss SY-1000.

Elantric

The first gen Fender "Roland Ready" Strats in the mid 1990's were made in Japan.

Then around 2000 they shifted production to Mexico.

In late 2011 production ceased.

In early 2012, the Fender  / Roland GC-1 arrived and this replaced the Fender "Roland Ready" Strat model.
(in 2015 Fender GC-1 production ceased)

There were occasional exceptions


1997 "Crafted in Japan" Fender Ritchie Blackmore Signature Strat with internal GK-2A:


https://www.fuzzfaced.net/ritchie-blackmore-signature-stratocaster.html


Elantric

If you post the serial number  - you can determine the place of Manufacture and year

All Fenders made in Mexico have a Serial Number on the face of the headstock that starts with "Mxxxxxxx" 
http://www.fender.com/support/articles/mexican-instruments-product-dating
Like this:

http://www.guitarrepairbench.com/guitar-dating/mexican-fender-serial-number.html







While most Fender Japan guitars have their Serial number on the back of the neck

Like this:


http://en.wikipedia.org/wiki/Fender_Japan

shawnb

Thanks, all!    ;D

I removed the ground connections connecting the pot casings, I moved the cap & pickup ground to the volume pot casing, and I applied lining to the cavity & grounded that to the vol pot casing also. 

I was incorrect in my earlier statement that the faceplate was shielded; it was not.  Where the white faceplate met the black paint just turned grey over time, making me think there was a layer of foil underneath the paint.   

I ultimately did exactly what Elantric pictured above!  Low budget, but it simply works.  Since the guitar jack is faceplate mounted, it's odd not connecting up the sleeve, but there is no need.   Removed the need for a couple of wires, making the job look minimalist.

The net result is a massive improvement.  There is still some noise of course, with tone & vol maxed out & the amp gain turned up.  But I was VERY happy with the results - BEFORE I realized I still had my fluorescent work lamp on!   

I am certain that concordal is correct and that I would get further improvement with better product/thicker shielding. 

Once again, this forum is the best!   A functional first attempt at wiring up a guitar, adding some functionality and reducing noise.

Shawn

PS - I am afraid to post pictures because I'm CERTAIN I'll get another YIKES out of Elantric!    ;D

PSS - What an absolutely horrid guitar design!!!  '78 Rick 420.  The bridge floats (see the pic above); it's held in place by the strings & the faceplate...  The intonation is WRONG, but to fix, I'd have to cut a new faceplate...  The faceplate is way too flexible.  The jack is faceplate mounted, and is probably ~200 uses away from tearing a massive hole in the faceplate, which is already cracking around the jack.  The tip of the guitar cable, when in the jack, actually touches the wood of the back of the guitar!   I had to leave that portion of the cavity unshielded otherwise the cable would short!

The wood, however, is nice.  The feel of the body is very comfortable.  My buddy really likes the feel of that glossy Rickenbacker fretboard, nice for bending chords.  The fretboard has aged very well, no longer 'glassy', just right.  Tuners are surprisingly solid. 

Maybe in two years, when that faceplate predictably fails, I'll do a whole new metal faceplate & mount the jack to the guitar body.  But for now, I'm done!
Address the process rather than the outcome.  Then, the outcome becomes more likely.   - Fripp

shawnb

PSSS - Not explicitly specified above, but I used two layers of foil for the cavity as well.   This was after talking with the guys at a local guitar & repair shop last night.  They were going to sell me shielding, & when they realized they were out, gave me a stage whisper to try a couple layers of foil...  They'll remain nameless, as I'm sure this is not a practice a pro would openly want to be associated with...   (I think Elantric knows exactly who the guys are I was talking with!)
Address the process rather than the outcome.  Then, the outcome becomes more likely.   - Fripp

shawnb


OK...   I replaced the faceplate-mounted jack with one that went in the side.   The flexible/cracking faceplate, the foil backing, a faceplate-mounted jack - bad formula.   New guitar jack into the side.  Much better.   This will last. 
Address the process rather than the outcome.  Then, the outcome becomes more likely.   - Fripp

Elantric

I've  worked on  several custom guitars with lucite bodies, but ultimately had to provide a shielded path to earth ground the plastic areas to bleed off electrostatic build up that occurs during strumming. This might explain the new recent presence of the black mesh screen within the plastic area on the ROR BE MIDI guitars. I'm curious about the high susceptibility of "snapping / cracking" noise being induced in the audio signal due to electrostatic discharge due to this design.
https://www.rorguitars.com/products/infinity-guitar




For example in 1961 Leo Fender tackled this electrostatic discharge issue on Strats by including a die cut piece of thin aluminum that matched the full size of the pick guard, that was laying directly under the early 1960's Strat plastic pick guard.
By 1965, CBS  deleted this important shield as too costly


Today many strats only apply metal foil in the control area  - but neglect the open exposed plastic in the strumming areas.

If you don't shield the entire plastic pick guard  - then midway through your first song, electrostatic charge is built up on the dielectric plastic pick guard and manifests as periodic "snapping / cracking" noise being induced in the audio signal due to electrostatic discharge. 





The video above identifies the problem, but IMHO the suggested solutions (sanding back of pick guard and dryer sheets) do not tackle the problem completely.
I prefer using aluminum foil cut the full back surface area of the pick guard and glue it to the back with an UHU glue stick. - solves the static noise 100%


(Elmer's GlueStick at Staples Store
.
See more details here:
https://www.vguitarforums.com/smf/index.php?topic=6807.msg47207#msg47207




Actually I find internal Ground Loops not to be much a problem or as big a source of noise with my internal guitar wiring.
But i do always find another type of noise on MANY New guitars that have the controls mounted on a"plastic pickguard" that MUST be tamed in only one manner -  Foil shielding applied to the complete underside of the pick guard is mandatory - particularly directly under the areas of the pick guard where you strum. Its not to eliminate "hum", instead its required to tame a "rice crispy" static build up / discharge noise effect that is a result of electrostatic charge build up on the plastic pickguard material. If you do not have this type of a foil shield applied directly under the pick guard areas where you strum, you will be doomed to always hearing a brief slight "crunchy / static" noise in your audio stream -  coinciding with each strum of your right hand on the guitar strings.


Lately i use a Glue stick (office supply store) and Aluminum foil applied to the underside of the ENTIRE pick guard - more foil than simply confined to the typical electronic cavity area on all my guitars.

http://www.amazon.com/UHU-Glue-Stick/dp/B001HTKBLQ/ref=sr_1_7?ie=UTF8&qid=1345152845&sr=8-7&keywords=uhu+glue+stick






No need to solder a ground connection to the Aluminum Foil - just mount the Pots and switches to the pick guard and tighten the nuts, and this insures an electrical Earth  Ground connection is accomplished.

Elantric

For more perspective, ESD Static charge "rice crispy noise as you strum" has been a battle with most guitars that feature a full plastic pickguard. The orignal Late 50's  - early 1960's Strats used a sheet of Aluminum cut to the same size of the pickguard and provided shielding and static charge dissipation.


Also since we are talking about grounding and shielding - myself i avoid guitars with "Black" metal hardware, Black plated bridges, Black output jack plates, etc.  Get an ohm meter, set to the lowest setting (0-100 ohms) and measure all your Black metal parts and discover that many parts with Black plating exhibits a very  Hi-Z impedance and is a poor electrical conductor. 

I recently worked on a two year old Peavey guitar with all Black plated metal parts and it was the noisiest  guitar I have played. Turned out there was an ineffective  string ground because the non conductive black plating on the bridge was acting as a dielectric insulator to the factory string ground wire sitting under the bridge.

Elantric

#16
Regardless - I always advocate adding more foil shielding under the pick guard to those areas where none is currently present  - not for hum - but for reducing static discharge rice crispy static sounds during strumming but also for achieving  better tone due to the effects of Paramagnetism (read on)

Leo had got things right , below is backside of a genuine '61 Strat pickguard  - revealing the Kaiser aluminum Ground Shield attached under the pick guard.
Then in 1966 CBS took charge and changed the Strat's BOM (Bill of Materials) to cut costs,  so they deleted it, and replaced it with small triangle of foil under the control area only.  CBS changed many other things too , like using a lower cost cast Tremolo block instead of the steel Trem block, larger headstock, and PU redesign.



Most are labeled Kaiser Aluminum


But read about paramagntism -  I can confirm when working on Stevie Ray Vaughns #1 Strat back in 1982 this same Kaiser Aluminum shield was in place under his pickguard and below is a discussion about the impact of the presence of this aluminum shield actually has on the resulting tone signature of those early pre CBS Strats
http://www.tone-guard.com/LeoFendersToneSecret/Leo_Fender_Secret_Tone_Formula.html





Leo Fender's Tone Secret - Paramagnetism

Leo Fender discovered that using metal shielding, i.e; metal control covers and pickguards, reduced the hum associated with his single coil pickups.

Lap steels and Guitars - Leo was using chrome steel covers and brass shielding on his lap steel instruments as early as 1947. Did you know Leo started making lap steels in his radio repair shop in Fullerton, CA? Who was his first partner and what was the company called? *Answer Below, at the Bottom of this Page.

When Leo started Fender Musical Instruments, he was using the single coil pickups he developed for the lap steels, but now he was putting it in a new guitar called the Telecaster. Later he developed new versions of the single coil pickup for the Stratocaster, P-Bass and Jazzmaster guitars, to name a few.

In 1957-58, Leo used an aluminum pick guard on the Stratocaster, Precision Bass, Jazzmaster, Mando-caster (Mandolin), and Duo-Sonic guitars. The tone that those guitars could generate is legendary! Today builders and players are seeking the Holy Grail of the tone that those guitars could produce, the womanly bluesy tone as some call it.

Here's the secret to that tone - Even if you buy reproduction perfect parts and have a master Luthier build it. You will not reach that soulful tone without using an aluminum pick guard. Why? Paramagnetism effects the high notes, by "rounding out" the ice picky highs found in many pickups.

We use what Leo used; .0625 (metric) or what we also know as aircraft grade 14 gauge aluminum, in the USA. The aluminum he used was 6061-T6. We use the same material and thickness. We think Leo had the correct thickness as well. Who could argue with the results?

Actually, it was likely happenstance, as material's were limited after WWII. Hence we have the tonal results of the chaos of that time and the good and diligent efforts by Leo to produce a sound that players wanted, besides easily replaced necks and components for road worthy instruments, the players needed.

The effect that the aluminum guard has is based on the principle of Paramagnetism. Leo did not know this was the scientific reasoning. Neither do most of the pickup and guitar makers out there. I even discussed this with a former JPL/NASA physics expert, working as a consultant to a famous pickup maker. He did not know the answer. He actually had no answer as to how an aluminum pickguard could effect a pickup? I found out by researching something a machinist / guitar player mentioned to me about magnetism and tooling. I read a lot of info on magnetic principles, found many useful sites on the internet, and distilled it down to what we guitar folks wanted to know.

Answer: Paramagnetism - Where the nonferrous aluminum is temporarily slightly magnetized in the immediate magnetic field of the pickup. See the Pickguard Specs page link in the sidebar for charts on materials and effect measured.

Almost imperceptible to some ears, and immediately noticed by others, it can effect the high end ice picky highs, rounding or softening them slightly. Not to be confused with microphonic issues. I hear some guys say the aluminum guards induce or cause the pickups to be microphonic. This is flat out wrong. They confuse the cause of the issue. It's your pickups, not the guard!

Though, the first thing you'll notice is that with most single coil pickups, the dreaded 60 cycle hum is greatly reduced or eliminated. This can make a Squire Strat sound as good as an American Strat! No kidding, we have A/B'd and demoed it.

This effect is in addition to the shielding from common sources of interference (RFI/EMI), static reduction, and the added resonance that using an aluminum guard can bring to your palette of tone "colors" in your search for your tone.

What Bill was talking about was the bridge plate, but the same answers hold true. A bridge plate is much thicker than a guard or cover. Also, steel for a bridge surrounding a pickup is going to effect the tone because steel is a ferrous metal that can be magnetized, hence altering the magnetic field of the pickup.

This begs the question: Why did Leo Fender stop using aluminum guards? I'll be sharing some information I got from Leo's longtime friend and business associate George Fullerton. I had the good fortune to meet Mr. Fullerton, many years ago, before his passing; and we spent some time talking about this subject To be continued......


Q: A builder recently asked the following question about using aluminum:

"I was reading an article by Bill Lawrence the pickup guru on aluminum bridge plates for Telecasters.  He was saying that aluminum is a great shield for electronic signals but if the aluminum is too thick it would blanket some of the high end of the guitar. I was curious if you chose your aluminum thickness by studying the acoustic properties, cosmetics or both.  From reading your website and talking to you in person I know you picked up your research where Leo Fender left off but I'm curious as to what you have learned."

A: The short answer for you is; yes, thickness can have a differing effect. Depends on how hot the pups are wound and the strength of the magnets used.


A little info about HyperPhysics and magnetics:

Magnetic Properties of Solids

Materials may be classified by their response to externally applied magnetic fields as diamagnetic, paramagnetic, or ferromagnetic. These magnetic responses differ greatly in strength. Diamagnetism is a property of all materials and opposes applied magnetic fields, but is very weak. Paramagnetism, when present, is stronger than diamagnetism and produces magnetization in the direction of the applied field, and proportional to the applied field. Ferromagnetic effects are very large, producing magnetizations sometimes orders of magnitude greater than the applied field and as such are much larger than either diamagnetic or paramagnetic effects.

Check out these links to read more scientific data on the subject.

http://en.wikipedia.org/wiki/Paramagnetism
http://en.wikipedia.org/wiki/Permeability_(electromagnetism)
http://www.physlink.com/education/askexperts/ae595.cfm
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

Check out the right side table of contents of the Hyperphysics page. Scroll down to Paramagnetism. Also check out the Overtones and Harmonics section. Fascinating reading if you like knowing why and how stuff works. I know, I do.

* Answer to the question above: Doc Kaufman, K&F. What did they make? Lap steels.

If you liked this information, please Like our Facebook page.



More info:


Magnetic Field Characteristics


Magnetic Field In and Around a Bar Magnet: As discussed previously, a magnetic field is a change in energy within a volume of space. The magnetic field surrounding a bar magnet can be seen in the magnetograph below. A magnetograph can be created by placing a piece of paper over a magnet and sprinkling the paper with iron filings. The particles align themselves with the lines of magnetic force produced by the magnet. The magnetic lines of force show where the magnetic field exits the material at one pole and reenters the material at another pole along the length of the magnet. It should be noted that the magnetic lines of force exist in three dimensions but are only seen in two dimensions in the image.



It can be seen in the magnetograph that there are poles all along the length of the magnet but that the poles are concentrated at the ends of the magnet. The area where the exit poles are concentrated is called the magnet's north pole and the area where the entrance poles are concentrated is called the magnet's south pole.


Diamagnetic, Paramagnetic, and Ferromagnetic Materials


When a material is placed within a magnetic field, the magnetic forces of the material's electrons will be affected. This effect is known as Faraday's Law of Magnetic Induction. However, materials can react quite differently to the presence of an external magnetic field. This reaction is dependent on a number of factors, such as the atomic and molecular structure of the material, and the net magnetic field associated with the atoms. The magnetic moments associated with atoms have three origins. These are the electron motion, the change in motion caused by an external magnetic field, and the spin of the electrons.
In most atoms, electrons occur in pairs. Electrons in a pair spin in opposite directions. So, when electrons are paired together, their opposite spins cause their magnetic fields to cancel each other. Therefore, no net magnetic field exists. Alternately, materials with some unpaired electrons will have a net magnetic field and will react more to an external field. Most materials can be classified as diamagnetic, paramagnetic or ferromagnetic.

Diamagnetic materials have a weak, negative susceptibility to magnetic fields. Diamagnetic materials are slightly repelled by a magnetic field and the material does not retain the magnetic properties when the external field is removed. In diamagnetic materials all the electron are paired so there is no permanent net magnetic moment per atom. Diamagnetic properties arise from the realignment of the electron paths under the influence of an external magnetic field. Most elements in the periodic table, including copper, silver, and gold, are diamagnetic.

Paramagnetic materials have a small, positive susceptibility to magnetic fields. These materials are slightly attracted by a magnetic field and the material does not retain the magnetic properties when the external field is removed. Paramagnetic properties are due to the presence of some unpaired electrons, and from the realignment of the electron paths caused by the external magnetic field. Paramagnetic materials include magnesium, molybdenum, lithium, and tantalum.

Ferromagnetic materials have a large, positive susceptibility to an external magnetic field. They exhibit a strong attraction to magnetic fields and are able to retain their magnetic properties after the external field has been removed. Ferromagnetic materials have some unpaired electrons so their atoms have a net magnetic moment. They get their strong magnetic properties due to the presence of magnetic domains. In these domains, large numbers of atom's moments (1012 to 1015) are aligned parallel so that the magnetic force within the domain is strong. When a ferromagnetic material is in the unmagnitized state, the domains are nearly randomly organized and the net magnetic field for the part as a whole is zero. When a magnetizing force is applied, the domains become aligned to produce a strong magnetic field within the part. Iron, nickel, and cobalt are examples of ferromagnetic materials. Components with these materials are commonly inspected using the magnetic particle method.


http://www.tone-guard.com/LeoFendersToneSecret/Leo_Fender_Secret_Tone_Formula.html

Elantric

http://english.stackexchange.com/questions/254458/why-is-white-noise-called-static

QuoteTrue "static" wrt radio reception usually does not happen on FM, at all. (It can, if the source of the interference is extremely strong, or if the FM receiver's "AM rejection ratio" is poor, but this is uncommon.) It happens on AM.

It is indeed caused by discharges of static electricity - hence the name - mostly in the upper atmosphere. This noise was called "static" long before Edwin Howard Armstrong developed FM radio, in a successful quest to vanquish the noise.

The term is apt: If you tune an AM radio to an unused frequency, and then shuffle across the floor and touch a doorknob - or separate two dissimilar fabrics, fresh from the dryer, from each other - or pet a cat - ideally all in cold dry weather - you will produce static discharges (some big enough to see and feel as sparks), and you will hear pops and clicks in the radio speaker that are exactly like the rest of the "static" you hear on AM, except in intensity.

( Heck, Heinrich Hertz first created the first (known) human-generated radio waves in exactly this manner, by making sparks. I say "known" because people have obviously been making static discharges for forever, but we didn't know they produced electromagnetic waves - radio waves - until then. "Spark-gap" transmitters were all we had until rotary alternators came along. (Tesla's patents that are supposedly for "inventing radio" concern the rotary alternator, which was later improved on by Alexanderson.) )

So - why is FM interstation hiss called "static"? In technically correct usage, it isn't. In common use, though, when FM came along, people didn't distinguish between the hiss heard on an untuned FM receiver and the "static" pops and clicks from AM. They just knew that the latter had been called "static", and so in popular usage this was generalized to "noise from a radio receiver (and, later, TV receivers) when tuned to a weak or no station".

admin

#18
I own several guitars which "stock as shipped new" exhibit a major fault, rice crispy crackle sounds that are directly coincident with full strums on the guitar.

Makes you wonder if the production crew at Fender or Gibson are deaf.

( I figure they just play metal legato shred , and never play rhythm guitar.

Solve Electrostatic Discharge "rice crispy" sounds
https://www.vguitarforums.com/smf/index.php?topic=12895.msg78045#msg78045


Static crackle
https://www.thegearpage.net/board/index.php?posts/26041897/

ESD Static charge "rice crispy noise as you strum" has been a battle with most guitars that feature a full plastic pickguard. The original Late 50's - early 1960's Strats , Jazzmasters, Jaguars all used a sheet of Aluminum cut to the same size of the plastic pickguard and provided shielding and static charge dissipation.



For example in 1961 Leo Fender tackled this electrostatic discharge issue on Strats by including a die cut piece of thin aluminum that matched the full size of the pick guard, that was laying directly under the early 1960's Strat plastic pick guard, and tied it to earth ground. The large surface area of the metal under the pickguard provides a path to dissipate the excess electrons from static charged surface area of the plastic pickguard.   

More details

https://electrostatics.com/staticelectricity.html


QuoteStatic Electricity & Static Control explanation, techniques and ionization products to control and eliminate static electricity using anti static eliminator equipment

The Purpose of this article is to help the reader answer some questions about static electricty: What is static electricity?; How to solve static electricity problems?; How to neutralize or control static charge?; How to remove static charge from non conductive material suce has plastic, paper and glass. STATIC ELECTRICITY: Static electricity is an imbalance of electric charges within or on the surface of a material or electricity at rest. Static Electricity is electricity but its characteristics create problems which cost industry billions of dollars per year. A clearer understanding of static electricity and electrostatics can be gained by explaining lightning. Static electricity in the atmosphere is in an unbalanced state remains at that way until the potential gradient, between clouds, reaches a level that causes the insulator between clouds, in this case air, to break down or fail. Lightning is created to equalize the potential gradient. For the brief instant the lightning flashes, the static electricity becomes the more familiar electricity is no longer at rest.
What do we know about this phenomenon called "static electricity" or "electrostatics" or "static shock"? What is static electricity and how do we remove static electricity or at least control / reduce static electricity? The information below will help you to understand static electricity and to control the costs associated with it.

CAUSE
Static electricity is generated by an unbalance of the molecular construction of relatively non-conductive insulators such as plastics, paper, glass, ceramics and other non conductive materials. All matter is composed of atoms. A balanced atom contains positive charges that are present in the nucleus of the atom. An equal amount of negative charges orbits this nucleus in the form of electrons. Both charges are equal and, therefore, the overall charge of a balanced atom is zero. However, should this configuration be disturbed and several electrons removed from this atom, we end up with a greater positive charge in the nucleus and a deficiency of electrons, which gives you an overall charge in the positive direction. Conversely, should we add a few extra electrons, we have an overall charge of negative, due to the fact that we now have an excess of electrons and the net charge is now in the negative direction. See figure below.
static control what is static electricity

Some materials such as glass, hair, and Nylon tend to give up electrons and become positively charged.  Other materials such as Polypropylene, Vinyl (PVC), Silicon, Teflon, Silicone tend to collect electrons and become negatively charged. The Triboelectric series is a listing of various materials and there tendency to charge positive or negative.

CONDUCTIVITY

The ability of material to surrender its electrons or absorb excess electrons is purely a function of the conductivity of the material with which you are working. For example, a pure conductor, such as copper, has a rigid molecular construction that will not permit its electrons to be moved about freely. However, as you approach the semi-conductor range, such as some bond papers, the ability of this material to surrender its electrons is relatively easy and can be accomplished by friction, heat or pressure. As you approach the purely non-conductive materials, such as plastics, glass ceramics, it is extremely easy to disrupt the molecular construction and cause the material to charge with the slightest friction, heat or pressure. If the conductivity of your processed material can be controlled, then, preventing static electricity becomes relatively easy.  However if the material is nonconductive static electricity can build up on the material.

For example, adding surface conductivity to plastics will move them up into the higher conductivity range and prevent the build up of static electricity that is caused by friction. This is normally accomplished by use of additives such as moisture and anti-static sprays. The average anti-static spray is made up from a soap based material that's been diluted in a solvent, such as mild alcohol. A fire retardant is added to combat flammability of the solvent. A short time after contact with your material, the fire retardant and solvents evaporate leaving you with a conductive coating on the surface of the material. The plastic has now become conductive and as long as this coating is not disturbed, it will be difficult to generate static electricity in this material.





Today cheap strats only apply metal foil near the Vol / Tone pot control area - but neglect the open exposed plastic in the strumming areas.

( Are they deaf ?, because I can clearly hear the rice crispy sound of ESD Discharge on my headphones when tracking Rhythm tracks on any guitar with a plastic pick guard that lacks a full metal foil shield )

If you don't shield the entire plastic pick guard - then while strumming midway through your first song, your hand movement   across the pick guard  creates a build up of electrostatic charge upon the dielectric plastic pick guard surface area,  and ESD discharge manifests as periodic "snapping / cracking" noise being induced directly into the guitar's audio output signal with each new strum, or hand movement near the pick guard due to electrostatic discharge.


the new problem is in a goal to increase daily production yield, manufacturer's have begun using electrostatic coating techniques for applying the paint finish, which today's formulations no longer adhere to the 1950's Lawrence MacFadden nitrocelluolose lacquer formulations
http://www.lmii.com/nitrocellulose-lacquer-solvent-based


Instead today, companies have migrated to Electrostic coating process for guitars, which allows them to paint more guitars per day   
https://en.wikipedia.org/wiki/Electrostatic_coating


But there are side effects from this process.

I have a 2013 GIbson SG and its a bit of a nightmare with lots of static discharge rice crispy noises  - even touching the plastic covers on the P90 pickups yield lots of ESD noise in the audio path from the guitar

I had to line the bottom inside of the P90 plastic cover with copper tape and tie to earth ground to minimize this ESD effect, but the effect remains due from the panted surface area.

Part of why I  choose Gibson Custom Shop guitars, which are still painted in the older nitrocelluolose lacquer application process they used back in the 1960's. 



Although with the guitar above, 1st course of action would be line the underside of all plastic areas in the strumming area ( PU covers, Pick guard) with conductive metal foil, and tie the foil on each to earth ground.

https://www.gearnews.com/gibson-usa-2018-gary-clark-jr-signature-sg-gloss-yellow/#comment-1446

QuoteComment:
The setup of this guitar from the factory was terrible but thats not the real problem. The new electro-charged finish has made this guitar unplayable when plugged in. The static electric pops are unbearable. I tried everything from shielding, humidifier, and static dryer sheets. Nope. Gibson said to send it back to them and they will look at it. I'll just sell it and get something else. Very dissatisfied.


Ironically - I also a guitar with similar three P90 pick ups as the Gary Clark JT Gibson SG

Reverend Warhawk



Reverends are made by Mirr Music in South Korea.
https://www.reverendguitars.com/support/faq
https://tonereport.com/blogs/tone-tips/price-pride-and-prejudice

yet I do not have a battle with rice crispy noise on my Reverend Warhawk,

Might be due to the metallic Red finish which is tied to Earth ground in the control cavity. I believe this metallic finish tied to ground aids in minimizing ESD discharge noise when strumming 

GuitarBuilder

Every new Strat-style guitar I build has full shielding on the back of the pickguard; I get mine with adhesive backing from Stew-mac:

http://www.stewmac.com/Pickups_and_Electronics/Shielding/Pickguard_Shielding_Foil.html
"There's no-one left alive, it must be a draw"  Peter Gabriel 1973

admin

#20
Quote from:  GuitarBuilder on April 07, 2018, 09:42:20 AM
Every new Strat-style guitar I build has full shielding on the back of the pickguard; I get mine with adhesive backing from Stew-mac:

http://www.stewmac.com/Pickups_and_Electronics/Shielding/Pickguard_Shielding_Foil.html

Related. Read how the Kaiser Aluminum shield on 1961 Strats rendered unique tone on those guitars due to ParaMagnetism.



https://www.vguitarforums.com/smf/index.php?topic=6807.msg127339#msg127339


http://www.tone-guard.com/LeoFendersToneSecret/Leo_Fender_Secret_Tone_Formula.html


cags12

Quote from:  admsustainiac on April 07, 2018, 09:58:32 AM
Related. Read how the Kaiser Aluminum shield on 1961 Strats rendered unique tone on those guitars due to ParaMagnetism aka Diamagnetism



https://www.vguitarforums.com/smf/index.php?topic=6807.msg127339#msg127339


http://www.tone-guard.com/LeoFendersToneSecret/Leo_Fender_Secret_Tone_Formula.html

Since I own my PRS (Which does not have any cavity shielding at all) I wonder if shielding is really needed at all on guitars. My PRS is dead quiet.

admin

#22
Quote from:  cags12 on April 07, 2018, 10:17:43 AM
Since I own my PRS (Which does not have any cavity shielding at all) I wonder if shielding is really needed at all on guitars. My PRS is dead quiet.


It may have electrically conductive paint shielding in its control cavity tied to earth ground.
Get an ohm meter.


The big test is connect your guitar into a professional d i box into a professional recorder and monitor your guitars direct sound ( no amp modeler) with headphones while strumming cowboy chords.

do it for several minutes. if you start to hear a coincident Rice Krispie faint crackle sound with each downward strum or even a crackle noise when your hand scrapes across your guitar top , then you have an electrostatic discharge problem.
most folks never hear this because they're focused on hum or noise issues while auditioning with a hyper hyper metal overdrive effect playing speed metal legado riffs

Some folks believe its just part of the electric guitar experience and their brains have tuned this ESD crackle noise out , or just assume its a bad guitar cable ( which also can be a source of similar noise in GK systems  ) and   figure it's just typical  noise


So it  really depends on if you have ears for it

For Some studio players  it's a major deal to tame that Rice Krispie ESD noise, else they loose work when the producer hears constant crackles in their raw guitar tracks. 

Other folks it's no big deal and that's why the manufacturers get away with implementing the lowest cost solution that fits 90% of their customers needs.
( And neglect Leo Fenders 1961 solution to save cost ) 

But satisfying the 10% of customers who do hear these ESD discharge noises might cost a lot more money to implement a solution.

For whats worth my PRS SE Bigsby  hollow body suffered ESD crackles, but I solved it by adding sheilding under the plastic pickguard

HecticArt

Quote from: admsustainiac on April 07, 2018, 07:34:23 AM
Ironically - I also a guitar with similar three P90 pick ups as the Gary Clark JT Gibson SG

Reverend Warhawk



Its made in Korea by Wold Music ( same shop that does PRS SE, JTV Variax's)
yet I do not have a battle with rice crispy noise on my Reverend Warhawk,

Might be due to the metallic Red finish which is tied to Earth ground in the control cavity. I believe this metallic finish tied to ground aids in minimizing ESD discharge noise when strumming

Reverends are made by Mirr Music in South Korea.
https://www.reverendguitars.com/support/faq

admin