Jazz Shielding Pictorial (Big Images Warning)

[BlueTalon]

~ Later that morning...~

View attachment 5016983

Technically necessary? Nah. Looks cool? You betcha.

I bought tape that's supposed to have conductive adhesive, and have been wondering how well it would do. After tearing apart my shop for a couple of hours looking for my tester (that's what I get for "tidying up!"), I checked things over, and got consistent results from one end to the other. One piece of tape read the same as those several steps away, or in separate cavities.

View attachment 5016995

Seems pretty solid and ready to go!

Something I do that is both functional and looks cool is I solder the bridge ground wire to the corner of the control cavity, and then I cover it up with copper tape so it's invisible. Nobody is ever going to see it except me, but I still like doing it.

One of the things I do when I'm putting everything back together is check the continuity between the output jack and the pickup cavities & the tuners. If it all reads zero, I'm golden.

 

[Winslow]

One of the things I do when I'm putting everything back together is check the continuity between the output jack and the pickup cavities & the tuners. If it all reads zero, I'm golden.

I admire your thoroughness. Usually when I monkey with the electronics, I figure if all the right parts are touching the other right parts, and I don't hear anything odd when I plug it in, it's good to go.

But given how much effort I put into finding my [bleep]ing tester, I may just do that out of spite because I can!

 

[vivaknoxvegas]

I’ve begun a shielding and pickup swap project on a passive jazz. It’s going well, the copper tape is so easy to work with and very forgiving of this rookie. My question is;

do I need to overlap the cavities some if my pick guard is just smooth plastic, no metal to speak of on the surface touching the bass. I’ve already started overlapping it some, but I wanted to pause and ask the question.

Should I coper foil the back of the pick guard too maybe?

 

[BlueTalon]

do I need to overlap the cavities some if my pick guard is just smooth plastic, no metal to speak of on the surface touching the bass. I’ve already started overlapping it some, but I wanted to pause and ask the question.

Should I coper foil the back of the pick guard too maybe?

I would. The idea is to surround everything in the signal path that can pick up extraneous noise, and intercept that noise first with grounded shielding. It's not a faraday cage, but that's the effect you're shooting for. For your purposes, that means shielding the back of the pickguard where it covers the control cavity, and making sure the shielding on the pickguard makes good contact with the shielding in the control cavity. And then making sure all of it is grounded.

 

[soundog]

I just bought this roll of copper tape to shield my bass. I recommend it; sticks good, easy to solder, just strong enough, and VERY affordable.

 

[SpeakerBoxxx]

Ok... so I haven't read this whole thread but I have read a lot of it. I have a question regarding shielding a bass with rear-mounted controls (I haven't found the answer while reading this thread). Since there isn't a metal control plate like you find on most jazz basses, do I need to shield the plastic control cover?

 

[selowitch]

Since there isn't a metal control plate like you find on most jazz basses, do I need to shield the plastic control cover?

I would say you only need enough shielding on the underside of a plastic control plate to establish connectivity between the three edges and the bottom/sides of the cavity. So a partial shielding job should be adequate in that case.

 

[SpeakerBoxxx]

Thank you @selowitch, your answer is greatly appreciated!

 

[selowitch]

Thank you @selowitch, your answer is greatly appreciated!

It’s all about connectivity to ground among all the various shielded areas.

 

[BlueTalon]

Ok... so I haven't read this whole thread but I have read a lot of it. I have a question regarding shielding a bass with rear-mounted controls (I haven't found the answer while reading this thread). Since there isn't a metal control plate like you find on most jazz basses, do I need to shield the plastic control cover?

If you're going to the trouble of shielding the inside of the control cavity, then it makes no sense to leave the inside of the control cavity cover unshielded. I fully copper-tape the back of my control cavity covers, and it mates up with the copper shielding of the control cavity.

 

[SpeakerBoxxx]

I'm working on a custom build for myself using stacked knob pots and a 3-way pick-up selector. I plan on doing the star grounding / full shielding technique similar to the first post in this thread. Would somebody be willing to take a look at my schematic here and let me know if this will work? Should I be posting this somewhere else... please direct me if so. Kinda new here and still figuring things out. Many thanks in advance.

 

[BlueTalon]

I'm not the guy to check your electronic diagram, but I can tell you this -- that "star" ground is fairly useless in this context. As long as everything that is shielded is also grounded, then the shielding itself becomes the center of the star. Which means you can connect the bridge ground at one point on the shield, the jack ground at another point, and the pickups/pots at yet another point, and it's all exactly the same ground.

So do whatever is easiest. For me, it was connecting the ground at different points. If doing a star is easiest for you, then go ahead -- but it seems like an unnecessary PITA to make all the different grounds terminate at one point.

 

[TeeSee]

I admire your thoroughness. Usually when I monkey with the electronics, I figure if all the right parts are touching the other right parts, and I don't hear anything odd when I plug it in, it's good to go.

But given how much effort I put into finding my [bleep]ing tester, I may just do that out of spite because I can!

Yeah. finding your multimeter after you've not used it for 15 years, then getting batteries, then finding after all of that you've got a break in one of the cables..Arrrrgh!!

 

[TeeSee]

Hi Lyle, I've just seen this and hope you're well as this has been posted many years ago.
I'm looking at modding a lovely playing but very cheap Jazz Bass copy, and rather than all out bridge and pups straight away, I wanted to mod it from the ground up first before going silly on spend.
Your tutorial is brilliant and lays down the foundation before upgrading the electronics, which is my next stage.
My question is, how do you do your seam soldering and what type of soldering equipment did you use? Can you get away with the lead free solder you can only get these days which IMHO is pants to use, or do you think copper shielding tape with conductive adhesive on the back would work?
Thanks in advance and stay safe.

There have been a lot of questions about shielding and star grounding, so maybe this will help someone.

Here's the schematic I came up with to do this with:

View attachment 2309237

First, I took everything out of the cavities and cleaned them to get rid of dust and manufacturing residue. Then I applied copper foil with adhesive backing to the control and pickup cavities. I tack soldered the seams and made sure each piece of foil read 0 ohms potential with every other piece. Then I made copper tubes (wrapped the foil around a screwdriver shaft of the right diameter) that run from cavity to cavity, tack soldered on each end. I also screwed a ground lug to the wall of the control cavity through the copper shielding. See photo:

View attachment 2309238

Here's the shielding inside the pickup cavities:

View attachment 2309239

Here's a closeup of the ground lug:

View attachment 2309240

Here's the actual wiring on the pots (reference the schematic above):

View attachment 2309241

And here is the other side of the wiring:

View attachment 2309242

Here's the top side of the control plate:

View attachment 2309243

Now, while there is still single coil hum (reduced, but still there), there is no noise at all when the blend knob is centered, and the bass is quiet even when I'm not touching any grounded metal components (strings, bridge, controls, etc). Soon I will put Sadowsky hum cancelling pickups in and the bass will be dead quiet. I also will be installing a S-1 switch in place of the current volume pot to allow series/parallel switching. I'll post that stuff when I'm done.

But for now, I'm pleased. The bass is much quieter, and the control layout (blend, master volume, master tone) is much easier to work with than the stock 62 RI stacked volumes and tones.

The pickups have much more clarity now without being bright (which I can't explain, really, unless it's the cumulative effects of a lot of little changes, like how the pickups are loaded together in the stock configuration and how the absence of RFI and other environmental noise leads to clarity- who knows?).

The tone control is now also much more musically useful (I changed from the stock cheap ceramic caps to a Sprague 715P .047uf cap- the same value that was on the stock neck tone pot, but this cap, or maybe this schematic, allows for more of the tone to be rolled off if needed, and the "sweep" of the tone pot has a lot more "sweet spots").

Please note that I didn't do the actual soldering with the bass exposed like that. I had towels and scraps of old T shirt to protect the bass surfaces when the soldering gun was out.

 

[TeeSee]

I can't figure out how to edit my original question but what I meant was can you use the copper tape with conductive adhesive to overlay the vertical and horizontal seams rather than solder the seams? I've not really used lead free solder, but the only lead solder I have left now is really thick gauge which needs a small torch, (albeit I have lots of Fluxite - another banned substance) still that would flood the small compartments of a guitar tho.
Also it looks like your earthing lug was crimped on rather than soldered. Did that work ok for you?

 

[BlueTalon]

Can you get away with the lead free solder you can only get these days which IMHO is pants to use, or do you think copper shielding tape with conductive adhesive on the back would work?

Go ahead and use the copper tape. The stuff I get from ebay is thin, and I use several layers.

I can't figure out how to edit my original question but what I meant was can you use the copper tape with conductive adhesive to overlay the vertical and horizontal seams rather than solder the seams? I've not really used lead free solder, but the only lead solder I have left now is really thick gauge which needs a small torch, (albeit I have lots of Fluxite - another banned substance) still that would flood the small compartments of a guitar tho.
Also it looks like your earthing lug was crimped on rather than soldered. Did that work ok for you?

For the love of everything you hold dear, please DO NOT USE A TORCH ON YOUR BASS! There are solders that will work adequately with a soldering iron.

Don't be too concerned about a lug. You can soldering your ground connections anywhere on the shielding itself. As long as your shielding is all connected, the shielding itself acts as the center of the "star."

 

[TeeSee]

Nope. There's no way I'd use a pencil torch. I just haven't done any soldering for years and the last time I used the Sn/Cu solder I struggled as it seemed to have a higher melting point and went off quicker than lead solder. I've got some copper tape arriving today that's got conductive adhesive and I'll try to overlay the seams. I'll let you know how it goes.

 

[TeeSee]

Blue Talon,
another couple of things have occured to me while I wait for the tape to arrive.
I'd rather not do the OP's method of running the tape round a pencil to shield the 'tunnels' as it's adhesive and can only end in disaster and me losing the plot !
I'm thinking now about using shielded wire for the pups and the grounding wire off the copper shielding. What's confusing me is that all of the wire I'm seeing on Amazon seems to be multiicore. I would have thought it would've looked more like coaxial i.e. a single core with braided shielding on the inner insulation?
Here's an example.

Amazon.co.uk

 

[BlueTalon]

Blue Talon,
another couple of things have occured to me while I wait for the tape to arrive.
I'd rather not do the OP's method of running the tape round a pencil to shield the 'tunnels' as it's adhesive and can only end in disaster and me losing the plot !
I'm thinking now about using shielded wire for the pups and the grounding wire off the copper shielding. What's confusing me is that all of the wire I'm seeing on Amazon seems to be multiicore. I would have thought it would've looked more like coaxial i.e. a single core with braided shielding on the inner insulation?
Here's an example.

Amazon.co.uk

Before you give up on the tape idea, let me suggest something. Wrap some copper tap around a pencil with the adhesive facing out, and then wrap some more around the pencil with the adhesive facing in. Or find a drinking straw that the pickup wires will fit into, and which will fit in the channel, and wrap a few layers around that. Either of those options should give you a stout enough copper tube that you can slide through the channel without a problem.

I personally would choose to do one of those options rather than mess with the pickup wires. I know, at the end of the day they're just wires, but the thought of messing with them and then screwing something up gives me the heebie jeebies.

 

[TeeSee]

Ooh..good call. Thanks for that, I'll have a go.
I was going to start the mod this weekend but I'm going to delay now until next weekend, the reason is what's the point in desoldering everything to lay the tape when I was going to upgrade the electronics too. So I'm waiting for delivery of CTS pots, an orange drop and Switchcraft jack socket which will be arriving Friday. I've also bought a half decent budget bridge from Northwest Guitars in the UK as the cheap stock bridge screw heads partially stripped as I was adjusting the intonation.
I'll keep you posted on how it goes, with a few pictures. I created a post a few weeks ago on here for a minor mod to my JB clone, so I'll probably expand in there.
Harley Benton JB-75 Minor Mod