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Cavity Grounding


skibum5545
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Of course we do. Antagonizing us won't make us answer any faster. :D

The screws don't matter at all. But everything else must be "connected." That means you should get a dab of solder where one piece meets another piece. Of course it can be anywhere along the joint. Then make sure a piece comes up and rounds over the corner of the cavity onto the area that the cover touches. Then do the whole cover. For a good solid ground you can solder a wire from ground to somewhere on the shielding, but simply making contact with the potentiometers should be enough.

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Maybe I'm missing something but ...

I shielded the whole of the internal cavity on my Ibanez RG550 (scratchplate mounted electronics) with aluminium tape I bought from an automotive shop. Installing it took ages as the cavities are complicated shapes and I ended up just working with small bits of tape at a time. This is earthed with a single wire from the back of one of the control pots to a screw put straight through the tape and into the body. I get my electrical tester out and check for continuity between any earthed component and any part of the shielding and it is totally fine.

My point being, I have read a number of times on this forum that you can't just use adhesive metal tape without soldering each bit to it's neighbour etc etc. I didn't do this, but still I seem to have acheived an acceptable result, i.e. continuous connection between every peice of tape.

Just thought I'd mention it.

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Sure, but its not a guarantee. The other pieces could also be getting grounded by the other components going through the cavity. So long as a connection is made you're fine, but if the adhesive lifts later, or if your connection is really weak than any shifting around could lift the connection. It's best to solder a connection, but if you don't it doesn't mean that contact alone won't ground it.

As a sidenote be careful with the tape. The edge can act as a razor blade and slice your finger right open. I have only gotten cut once, but I always have little lines in my skin after working with it. So maybe use gloves, or what I do is to apply and press/smooth it out with a dowel rod or something other than my digits.

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As a sidenote be careful with the tape. The edge can act as a razor blade and slice your finger right open. I have only gotten cut once, but I always have little lines in my skin after working with it. So maybe use gloves, or what I do is to apply and press/smooth it out with a dowel rod or something other than my digits.

Yup, just did it last night. Ouch!! :D

I'm interested in why you did this to your RG550? I looked at mine last night and noticed that they only shielded the pickguard and not the cavity itself. Did you add the tape to try to add more noise reduction? Did it actually help? Were you having problems with noise?

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I would reccomend geting conductive paint. Stewmac sells it. Ibanez does this from the factory. that is why there is no tape. They paint it with conductive paint.

You can recognize it by it's flat black appearance.

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Conversely, you could shield your cavities with heavy duty aluminum foil from the grocery store, and spray adhesive from your local craft shop. You can't solder aluminum, though, so you'll need to make sure you have some folded-over bits for interlocking pieces if you want it all in one continuous ground.

No matter what you use for the cavity (paint is reportedly less effective, but it WILL still work, especially if you do enough layers), using aluminum foil and spray adhesive is the easiest way to do the pickguard of a guitar, and the performance will be only marginally inferior to copper foil.

I have to admit, when I used aluminum foil, I did a bit of a messy job. It works like a charm, but if you like your stuff to -look- professional as well, you can't rush through it the way I did. The pickguard and control cavity cover are stellar, though. :D

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daveq - Since reading various articles, tutorials and forum topics telling how important it is to shield internally, I took it upon myself to shield the entire inside of my RG550 including replacing the original shielding on the back of the scratchplate. My shielding covers all of the internal cavities and all of the scratchplate to within 2mm of the edge. There is no noticable difference to anything, no more and no less noise than there was to begin with (which was hardly any). I have never had a problem with excessive hum or his that hasn't seemed to have be caused by bad earth connections to pots or jacks. So, does cavity shielding work and is it worth doing ..... nah.

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daveq - Since reading various articles, tutorials and forum topics telling how important it is to shield internally, I took it upon myself to shield the entire inside of my RG550 including replacing the original shielding on the back of the scratchplate. My shielding covers all of the internal cavities and all of the scratchplate to within 2mm of the edge. There is no noticable difference to anything, no more and no less noise than there was to begin with (which was hardly any). I have never had a problem with excessive hum or his that hasn't seemed to have be caused by bad earth connections to pots or jacks. So, does cavity shielding work and is it worth doing ..... nah.

Dunno about that (but speaking from no guitar experience mainly from PLC's and the like)

Might be worth not worrying about too much after it's done, but I'd still shield it. But then again experience is a better than theory any day.

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daveq - Since reading various articles, tutorials and forum topics telling how important it is to shield internally, I took it upon myself to shield the entire inside of my RG550 including replacing the original shielding on the back of the scratchplate. My shielding covers all of the internal cavities and all of the scratchplate to within 2mm of the edge. There is no noticable difference to anything, no more and no less noise than there was to begin with (which was hardly any). I have never had a problem with excessive hum or his that hasn't seemed to have be caused by bad earth connections to pots or jacks. So, does cavity shielding work and is it worth doing ..... nah.

I would guess that you don't play with very high gain.

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And you'd be wrong. When rebuilding my RG550 and doing the internal shielding, I also replaced the stock pickups with DiMarzio Evolutions to give me even more output. So, sorry, but try again.

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I'm guessing that some people benefit more from the sheilding than others due to the environment they play in.

For instance, one of my latest guitars has no shielding in the cavity at all yet and I have very little noise (same as another guitar with sheilding in it). I would expect that if I were to tour the country in a band that some areas would end up being more noisy than my basement. In those situations, the shielding may end up helping.

I don't have any hard facts for this but I think it makes sense.

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I would take that a step further and say that shielding is -completely- dependent on the environment you're playing in... hence the terminology! You're not shielding the guitar from itself, but from sources of interference around it.....

An example of a guitarist who would benefit greatly from a shielding job is one who spends a lot of their time as a 'bedroom producer', where they're surrounded by computers, monitors (though no amount of shielding will save you from sitting right in front of your CRT monitor), nearfields, mixers, etc.

Paulie, you hit the nail square on the head, whether you realized it or not, though-- you indicated that you never had problem with hum anyhow. So how COULD you notice a difference? Those of us with hum problems usually notice a significant improvement from a proper (all material grounded together, for instance) shielding job.

There's no such thing as perfect/complete shielding, as far as I know, but is it worth shielding your guitar? Yeah.

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I would guess that you don't play with very high gain.

And you'd be wrong. When rebuilding my RG550 and doing the internal shielding, I also replaced the stock pickups with DiMarzio Evolutions to give me even more output. So, sorry, but try again.

What does having Evolution pickups have to do with high gain? High gain and high output are two different things though many people confuse the two terms because they often produce similar results. I was referring to very high gain amplification and distortion.

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gregp - exactly. Even though I have done it, the fact that I had no problems in the first place means that for me, I have got no benefit. However, others may reap massive benefits from it. My original point was really only to point out that I had shielded mine with aluminium tape and there are no breaks in the continuity from piece to piece.

saber - I don't think that attempting to analyse my gain preferences or choice of pickup has any relevance whatsoever. So, does anyone use high output humbuckers like Evo's for that nice 'clean' sound. Christ, I can't even get get a clean sound out of them. So thanks for the technical input, but yes, I run the gain on 10, always.

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You'll benefit from significantly reduced hum if you star ground your electrics (see guitar nuts for detail). Effectively this means having all the grounds connected at one point to avoid ground loops - I usually use the body of my volume pot and connect all the earths to it. For this to work best, you need to insulate the other pots and switchs from the shielding, otherwise you provide an alternate route to earth, and introduce hum.

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saber - I don't think that attempting to analyse my gain preferences or choice of pickup has any relevance whatsoever.

But it is relevant. More gain (on a high gain amp) means more clipping bringing the noise floor up relative to the peak of the clipped signal. But if you didn't have any noise to begin with, then how could you expect an improvement? If you did have very slight hum or noise and it didn't improve with shielding the guitar, then maybe the source of noise is not the guitar but rather your amp or effects.

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