grd shield my Artcore semi-hollow electric questions

[Jim_L]

I've got an orange 2005 Ibanez Artcore semi-hollow electric that i'm really thinking about grounding properly. The problem is the only way to get inside the thing is through the F hole, there's no back access cover. Here's a pic of the guitar:

http://home.comcast.net/~castle.walls/musician/pics/studio2.jpg

 

I'm thinking of making a big hole in the back that a typical oval-ish cover would fit over (and overlap the hole and glue in some small pieces of wood inside under the edges where the screws would go to give added support and 'meat' for the screws to go into) depending on what type my local music store would have as far as shape/etc. would be. I can also cut that as needed prior to creating the hole in the guitar - all by dremel.

 

Anyway, my other thought is:

1) To obtain some grounding paint & paint the inside of the 'chamber'. I don't know how the F holed chamber would be affected.

2) Also paint the pups holes.

3) Make the 'tunnel/wiring' holes from the pups that go through the center of the body to the F chamber bigger for new shielded wires from the pups and also paint the inside 'tunnel/holes' too.

4) sand down the backside of the bridge of any chrome to get to the bare metal and paint that area/chamber. I know that there's just the thinnest piece of bare wire to the bridge from the rest of the wiring and making a 'connection' to the bridge by compression alone. Also opening up that wires tunnel/hole and painting the inside of it.

 

Has anyone else gone through this with a semi-hollow with no rear access? Tips? Advice?

 

I'm also thinking of rewiring the pups to split the coils, reverse phasing and, if possible, having the ability to use any combo of coils from both pups. I'd also like to install another output jack so i'll have one jack for each humbucker and be able to use both at the same time in order to facilitate my direct in home recording method (one pup for each track, actually, one pup each into a separate multi-effects pedal then out in stereo from each pedal into a total of 4 tracks. Niow I have to use multiple splitters directly from the single jack and only get the one pup sound).

[miroslav]

Sounds like a lot of work to achieve very little AFA grounding/shielding....and you will destroy the body by cutting a hole through the back. Is there something wrong with the grounding?

 

And why don't you just make two passes when recording...and record one PU the first time...and the other the second time?

 

But hey...it's you guitar, so I guess you can do anything you want to it.

 

[The Geoff]

You should have bought a different guitar.

 

If this instrument is so far away from your ideal, why did you buy it?

 

Surely it would have been better to buy one with a back-opening cavity if you want to mod?

 

Start hacking holes in the back of this guitar and you immediately reduce its value to ZERO.

 

And unless you have experience with all the above, it will be very easy to mess things up.

 

Please don't do it.

 

Ibanez are fairly decent instruments and a lot of professionals use them.

 

G.

[Jim_L]

For some reason, it's just gotten very noisy. It was not too bad as long as you kept in contact with the bridge/strings, but now it's getting worse (?). I did take the bridge off months ago to find the ground wire wasn't even protruding enough through the hole from the pot chamber to even touch the bridge. I fixed that and the ground was fine for a bit.

 

As far as the 'why' on the guitar, because it was the coolest looking guitar on the wall and caught my eye as soon as I looked at it, I then tried lots of other guitars (and much more expensive ones too) and wound up liking the sound & playability of the Ibanez.

 

I'm just looking to add sound/wiring options to the guitar as I doubt i'll ever have another unless i win the lottery...;>)

So, i'm not worried about it's value.

 

Yes, I can do all sorts of wierd track recording methods with my splitters (6 at once so far) but the effects used all go to the same tracks unless I want to get too creative with splitters and such, having 2 outputs would just make life easier. Call it bordom in my old age...;>)

[Jim_L]

p.s. i'm also thinking what the guitar would sound like with 3 separate single Hummbucker/stacked pups (maybe 4) side by side and turned sideways...

That would cover the strings vibrational area...

[miroslav]

Well...maybe you should do a little research on Robert Fripp (maybe you already have)...and it will give you some more ideas on how to rig up your guitar for recording.

 

Hey...if you want to turn your guitar into an experimental axe...that's cool. Break out the Dremel and the soldering iron and go for it.

 

I just have a feeling that your grounding issues may be coming from some other place. And you could just get an electrical isolation box and say bye-bye to those issues.

 

[The Geoff]

I went through a period of modding the hell out of everything I had.

 

I'm *almost* over it now, but what do I play most now?

 

An un-modified Telecaster - as simple as it gets.

 

G.

[Jim_L]

Oh I wouldn't do anything until I had a solid answer/diagram. Just looking for 'that sound' in my head...;>)

 

It just might be a 30 watt tube head through a 2x10x1-18 bi-amped cabnet, but until they make a quiet tube amp that doesn't cost so damn much...;>)

 

I shoulda grabbed one of those Bedrock heads when I had the chance but the $$ was no where near what it was worth (I was the first employee of the company in Nashua NH years ago, I'm sorry but $1000's for a 'hand wired amp' that's built in an hour by a person making $8 an hour just makes me laugh...;>)

 

What I do miss are Peavey Black Widow speakers in the old Stereo Chorus 2x12 amp, now compared to my Spider 3 150 watt 2x12 combo, even tho' the S3 sounds great, it has no bottom punch at low volume (boy, did I go off topic or what?), so i'm playing around with many different 'thoughts' for my sound options.

 

I love my cheap little $299.0 Ibanez (at this time your probably thinking i'm nuts because splitting coils and such will only move my sound away from bottom punch - yes? Don't worry about it, I'm like this all the time, just ask my wife...;>)

 

I've tried my guitar through other amps and moved my amp throughout the house and had another guitar played through the S3, it's my guitar... even on the clean channel, tho' not as bad.

 

Most of my typical guitar recording method is to go into the board (Korg D3200 32 track deck) direct and record onto 2 tracks using a bit of the decks built in stereo chorus and pan both tracks medium to hard L & R. If I use distortion from the S3, I come out the headphone out into 2 tracks as above, I do the same with using either my Digitech RP150 or GNX3000 or Behringer X Vamp (but leave the amp out). I also wish someone made an EQ pedal with twice the bass slider distance of typical pedals. I just can't get that breast pounding controlled punch I dream about.

 

Well, enough rambling, maybe someone makes glow in the dark grounding paint, that with some lights inside the F chamber would look cool...

Sorry, rambling again...

;>)

 

oh, p.s. and whatnot, the ground from the guitar can be heard with the pedals too (direct) when I'm not touching metal, what is it about HAVING to touch the strings/bridge of a guitar that helps quiet hum? I'm not grounded to anything?!

[arneyz]

oh, p.s. and whatnot, the ground from the guitar can be heard with the pedals too (direct) when I'm not touching metal, what is it about HAVING to touch the strings/bridge of a guitar that helps quiet hum? I'm not grounded to anything?!

 

Your grounded to the ground. Seriously.

[miroslav]

...what is it about HAVING to touch the strings/bridge of a guitar that helps quiet hum? I'm not grounded to anything?!

 

Like arneyz said...you're standing on the ground/floor...etc.

 

But here's something to consider....

 

I have a bunch of guitars and a few amps in my studio...and every once in awhile, some will kick out a bit more buzz than usual...sometimes nothing.

I've traced a single outdoor fluorescent porch light as a MAJOR cause of AC buzz throughout the entire electrical systemno matter where I plugged in!

 

Anyway...like you said, when the hand touches the strings/bridge it's all quiet as mouse.

And really, doesn't one of your hands almost always touch the strings or bridge?

 

So while a little hum/buzz is annoying just 'cuz it's there, and we would all prefer not to have any...the reality is that you can still record pristine guitar tracks 'cuz one of your hands will always be touching the strings/bridge and kill the buzz during playing.

 

I just don't sweat it anymore in my studio...unless of course it's something out of the ordinary and it is filtering into all my gear...which is never the case.

But by all means, you should always try to trace the cause of the buzz/hum if at all possible, and eliminate it.

 

[Fumblyfingers]

I am going to throw in my 2 cents garnered over 40 years of playing.

 

Leave it alone!

 

I screwed up a perfectly normal Strat that I bought in 1970...untouched even with all the normal wear, it would be worth a heck of a lot of money today.

 

What we did not realize then was these instruments increase in value. In 20 years time who knows if that instrument will have become a collector even if it is just an Artcore.

 

You are not going to gain anything by putting in extra pickups. Nobody of any merit today is doing this, nobody puts 4 pickups in side by each.

 

Stock is better.

 

BTW , with humbuckers you do not need to shield it. What you need to do is find why it has a grounding problem...it is going to be a broken,loose or unattached wire.

 

You are more than likely going to end up with something you do not like if you go down this path and it will be worthless.

[BrianWren]

[W]hat is it about HAVING to touch the strings/bridge of a guitar that helps quiet hum? Im not grounded to anything?!

I have often wondered about this myself, and could not figure it out until I was actually asked from the outside just now by you. (Its wierd how having a question asked will coalesce thoughts in a way that cannot otherwise be accomplished...)

 

It is not just the strings/bridge, but any part of the guitar that is ground. If you reach in and touch the pickup covers, the effect would be the same. The same with touching the metal part of the jack plugged into the guitar (the part you unscrew to solder the wires) as well.

 

It is not that you are grounded, as others have suggested. (After all, you specified that in your question...)

 

But this is my thought. When you are not touching the metal of the guitar, virtually the only influence on the absolute voltage of the guitars ground is the ground conductor of the cable. Because of that, the absolute voltage of the ground is stable, so impinging fields have a lot of differential, compared to that ground. That differential induces a voltage in the components, relative to ground, and that is heard as noise in the signal.

 

Now, it is also true that you are an antenna for the ambient fields around you. Your absolute voltage rises and falls through the inducement of these fields.

 

When you touch the ground of the guitar, 2 things happen.

 

1) Your absolute voltage swings are attenuated by the grounding influence of the ground conductor of the guitar cable; therefore, you become a partial shield, stabilizing the electric field activity in your immediate vicinity. (Electric fields are a continuum. If the differential is 20V an inch from a grounded object, it will be 40V -- or so -- two inches from it, becoming a maximum at the surface of the source emitting the field.)

 

2) Your contact with the guitar causes its grounds absolute voltage to track with what you are picking up as an antenna. (Your voltage is more stable, but it is not completely unchanging.) When this happens, there is less differential between the impinging fields, and the electronics of the guitar, hence less signal voltage is induced.

[miroslav]

Yeah...but the same thing happens if you touch the strings/bridge with a piece of wire that goes to ground.

If that wire is floating...the buzz/hum will not go away.

 

Are you saying that we are not completing the ground, and instead are somehow "absorbing" the excess currents causing the hum/buzz...?

 

[Fumblyfingers]

1) Your absolute voltage swings are attenuated by the grounding influence of the ground conductor of the guitar cable; therefore, you become a partial shield..........2) Your contact with the guitar causes its grounds absolute voltage to track with what you are picking up as an antenna.

 

 

HUHHH!!!

 

You forgot forgot the neutrino's........those little bastards are flying through everything taking the positive vibes with them as they go through, leaving only negative vibes man.....just ask Sgt. Odd Ball.

[The Geoff]

1) Your absolute voltage swings are attenuated by the grounding influence of the ground conductor of the guitar cable; therefore, you become a partial shield..........2) Your contact with the guitar causes its grounds absolute voltage to track with what you are picking up as an antenna.

 

 

HUHHH!!!

 

You forgot forgot the neutrino's........those little bastards are flying through everything taking the positive vibes with them as they go through, leaving only negative vibes man.....just ask Sgt. Odd Ball.

 

It's electricity, Jim, but not as we know it!!!

 

 

G.

[Jim_L]

Alright, you guys have convinced me to give the ground issue another go. It makes me wonder if I should try 'wiring up' my strap and see if any 'sympathetic' sheilding may work (tied into the strap lock screw...). Though any real electrical 'shorts' would be a bitch...;>)

[Fumblyfingers]

As far as I know the ground circuit needs to be good all the way back to the wall socket. The strings ground by way of the bridge wire and/or spring claw ground in a vibrato system, then the pots are all in that circuit and off to the jack plug. That wire often frays or breaks from the jack coming loose and being spun while tightened... sometimes it will short. Then on to the amp which needs to be grounded and not on a lifter and then to the wall socket which needs to be wired correctly and be grounded.....a less than $10 tester from Home Depot will tell you this and should be in your kit. Every time you do a gig or rehearsal..... plug it into the socket you are going to use and make sure it is wired properly and has the ground.

[miroslav]

Yeah...what Fumbly said.

 

But I will add that there are days where your electricity just has more "dirt"...depending on what else is powered up and running in the room and in the same house/buildingmaybe even in the neighborhood!

I've had many 100% noiseless days...and times when Ill pick up the exact same gear...and I all of a sudden I have some buzz/hum.

 

So...you might have to do a little witch-hunt, that goes beyond the wall socket where you are plugging in your amp rig.....

 

[Trucks]

I had a Wireless Router with an AC adapter that caused all sorts of weird noise to come through the amp.. Especially if I flicked the wah wah on. When the AC adapter was unplugged everything sounded fine.

[Fumblyfingers]

So...you might have to do a little witch-hunt, that goes beyond the wall socket where you are plugging in your amp rig.....

 

Yeah...computer monitor, fridge, neon lights etc etc etc and a distortion pedal set to high gain/overdrive will help add noise as well.

[BrianWren]

Fumblyfingers,

 

Remember, just because we don't need to visit the technology all the time doesn't mean it doesn't apply.

 

I know technological answers aren't for everyone, but they might be interesting to some.

 

Just as it would be bad form to post in a RIP thread, Who is this guy? nevermind, I don't care, is seems bad form to me to make light of a technical post when it doesn't happen to be your cup of tea.

 

I mean, it seems the thing to do would be to mutter, "whadevah" and move on...

[Dr. Ellwood]

Be very glad we don't use these anymore!! http://i16.photobucket.com/albums/b48/ellwood1/503px-Tesla_Effect_Spark_Gap_Transm.png

 

http://i16.photobucket.com/albums/b48/ellwood1/mar13.gif

[The Geoff]

I'm surprised no-one has mentioned www.guitarnuts.com.

 

G.

[BrianWren]

[1] Yeah...but the same thing happens if you touch the strings/bridge with a piece of wire that goes to ground.

If that wire is floating...the buzz/hum will not go away.

 

[2] Are you saying that we are not completing the ground, and instead are somehow "absorbing" the excess currents causing the hum/buzz...?

1. I don't think this is the whole story. The ground wire of the cable should be doing this (electrically). So is supplying an external ground is helpful, I would be really suspicious that the ground path within the guitar is no complete.

 

2. I would say that it is not always (nor even typically) completing nor establishing ground. After all, Jim L stated flatyly that he was not providing ground.

 

It's not "absorbing." Everything is at some voltage (which is also known as potential, a term which I am now going to switch to). Even the earth has a potential. If you could do it, stretching a meter between the earth and the moon, you would probably measure a voltage between them. That voltage is the difference in their potential. There is no zero potential, because it is entirely relative.

 

Here on earth, we use the potential of the planet as zero, and we have named that ground.

 

Lets say there were 1,000V differential between the moon and the earth. If you put a plate ½-way between the two, and you put one lead from your meter on the earth, and one on the plate, you would measure 500Vthis is how it is manifested that I said there is a continuum of electric fields. It is more complicated than that though, because the surface area of an obect plays a rol in how firmly it can establish the potential of the electric field in its vicinity.

 

A guitar doesn't have much surface area connected to ground. The surface area of a person is larger, and so is able to more firmly affect the electric field in its vicinity. When a person touches the ground of a guitar, that person and the guitar will be at absolutely the same potential. This does not establish what that potential will be, only that it will be exactly the same.

 

With the stiffness with which a surface area such as the human body will establish its local electric field's potential, the guitar finds itself in a much less energetically varying electric field.

 

You can see this in effect with a radio, and a building. Even if you are on the same side of a metal building as the transmitter of a station you are listening to, as you move nearer to the building (a foot or so away) the signal starts to weaken. If you move within ½" or so, it is way more pronounced. The reason for this is that the building is stabilizing the electric field around it. Transmitters vibrate the electric field through their antena.

 

Well, in the same way, when you become grounded by touching the metal of the guitar, you are held to a stable potential, and, as an anti-antena, you stabilize the electric field around you (in which the guitar is.

 

But, to the degree that the grounding of your body and the guitar is not 100% stable, your contact with the guitar causes the guitar's ground to be moved around by the local field potential, so that the difference between the local field and the electronics of the guitar is not as large a difference.

[BrianWren]

Be very glad we don't use these anymore!! http://i16.photobucket.com/albums/b48/ellwood1/503px-Tesla_Effect_Spark_Gap_Transm.png

 

http://i16.photobucket.com/albums/b48/ellwood1/mar13.gif

What is it a photo of? (Photobucket is blocked here...)

[miroslav]

Brian...I get what you are saying.

Maybe "absorbing" was a bad choice of words. Maybe "balancing" makes more sense.

 

But...I've had guitars that I KNOW are properly grounded. No doubt about it, as I have painstakingly checked and rechecked them.

And yet...when once in awhile some hum/buzz creeps in...I've been able to take a wire and just touch the bridge and a grounded point in my studio...and the hum/buzz goes away.

So...I do feel we are providing some path to ground when we touch the guitar and the floor.

 

Would ANY object touching the guitar, while floating at the other end, still cause the hum/buzz to vanish (following your thoughts on "potential")...?

 

Heck...many have been zapped by a microphone, because we've completed the faulty circuit...even though we are not properly "grounded".

 

I'll have to do some more reading...your points are interesting.

 

[The Geoff]

I recently renovated a Double P bass.

 

I took great care to utilise star grounding for every component as I deliberately *didn't* want to use a bridge/string ground as I remember the on-stage death by electrocution via guitar strings and microphone of Lesley Harvey (Stone the Crows).

 

Despite the P pups being humbucking, the cavity *and* the pickguard being screened ands everything properly grounded (I've checked several times) I was *STILL* getting a buzz - mild and almost inaudable normally, more pronounced when the tube lights in the garage are on.

 

I've had to put a bridge ground in to kill this final signal on hand-contact, and re-introduce the danger of electrical shorting via the strings.

 

G.

[BrianWren]

Look at the pages at guitarnuts (link above) for the solution to electrocution while keeping grounding intact.

[Dr. Ellwood]

Be very glad we don't use these anymore!! http://i16.photobucket.com/albums/b48/ellwood1/503px-Tesla_Effect_Spark_Gap_Transm.png

 

http://i16.photobucket.com/albums/b48/ellwood1/mar13.gif

What is it a photo of? (Photobucket is blocked here...)

 

A spark gap transmitter.

[BrianWren]

I've had guitars that I KNOW are properly grounded. No doubt about it, as I have painstakingly checked and rechecked them.

And yet...when once in awhile some hum/buzz creeps in...I've been able to take a wire and just touch the bridge and a grounded point in my studio...and the hum/buzz goes away.

So...I do feel we are providing some path to ground when we touch the guitar and the floor.

 

Would ANY object touching the guitar, while floating at the other end, still cause the hum/buzz to vanish (following your thoughts on "potential")...?

 

Heck...many have been zapped by a microphone, because we've completed the faulty circuit...even though we are not properly "grounded".

 

I'll have to do some more reading...your points are interesting.

It is possible that the amp was not firmly connected to ground.

 

It's possible that the design of the amp isolates the input cable from ground, to eliminate some problems the designer found.

 

The more surface area the object touching the metal of the guitar, the more localized anchoring of the ambient fields.

 

Flourescent lights are extremely good radiators! They are antenna shaped, and the current through the tube is in series with a coil. This configuration gives them the ability to induce multiple-hundreds of volts higher potentials than incandescents.