Shielding a single coil pickup from a Rickenbacker Bass

[rabidgerry]

Hi guy's long time now post on

Anyways I am trying to shield my friends rickenbacker bass guitar. He is one of these types who likes to remove the silly pickup cover that only really covers the top of the strings and doesn't surround the pickup like normal pup covers. Anyways I was wondering what would be the best way to go about this?

My initial idea was to surround his single coil pickup with copper tape (I was just going to leave the backing paper on so it doesn't stick to the protective pickup tape)

then attach it to the earth on the actual pickup itself.

Is this the way forward do you think?

Oh and also shield the control cavity?


Or should I use brass gauze or mess instead of the copper tape?

I would be interested to hear all your thoughts on the matter.

I myself don't buy the whole "shielding affects your tone" thing but it's probably best to ask the experts on here anyways

Thanks

[newey]

Welcome back, rg!

A very long time ago on the Board, we had a discussion (which I can't find at the moment) about wrapping pickups instead of shielding the cavity. As I recall, the consensus was that this might affect the magnetic field around a pickup, and thus affect the tone, presumably deleteriously. However, some who tried this technique claimed good results without tonal loss. This was, IIRC, on the neck pickups of Teles and on LP pickups.

Just off the top of my head (i.e., no real data to support it), I would think any tonal effect would tamp down the highs, and thus, on a bass, it may not be so much of a concern.

So long as the wrapping process is easily reversible, I'd say try it and see what your friend thinks.

There will probably not be any difference between copper tape and a mesh.

[rabidgerry]

Thanks newey

Yeah I was actually thinking being a bass I may not lose anything I ever get out of the bass to begin with.

The reason I suggested the mesh stuff was because I remeber way back when I was a regular a post on here where someone shielded pickups successfully with zero (supposed) tone loss. And that was a debate on whether to use copper foil or not because the foil apparently would kill tone if it formed a complete loop which would then act as a coil blah blah so mesh was better apparently.

The reason I want to do this for my friend is because his Bass suffers greatly from interference from lights and stuff when ever his is near anything like that and it's not always a case of being able to move away. In our rehearsal room he can't get away from lights that are on the floor below him without them causing crappy buzz. I don't suffer myself as I use noise reduction etc and humbuckers.

I am going to try tape first

[sumgai]

'gerry,


Yer right, looooong time!


Mesh isn't the answer, that'll have the same effect on tone (little or otherwise) as solid tape. The answer turned out to be even easier - simply don't close the loop. Instead, go about 95% of the way around the pickup coil, then stop - leave a small gap. Tack solder an insulated lead to one end then connect that to a shielding/ground point.

At that point, you haven't created yet another coil, so the inductance factor should be negligible, thus the effect on tone should also be too small to notice.


If that doesn't work, and let's face it, a Rick bass's pickup is huge honkin' puppy, then you might consider a dummy coil for just this situation. A thread is "sticky-ed" just above this one, linked like so:

guitarnuts2.proboards.com/thread/1693/dummy-coil-experiment-successful

That's not a bad way to go, but for the sake of simplicity, you might use it as Plan B, and let the "almost coil" of tape be Plan A.

HTH






sumgai

[rabidgerry]

Hi sumgai,

thanks for the advice.

Ok first question, I only thought the coil would become a coil if the tape was touching the actual wire windings around the pole pieces, which is why I intend to leave the backing paper on the tape.

Second question is it ok to leave the backing paper on the copper tape do you think?

I intend to attach the tape simply by looping it round the pickup, peeling back a little so the sticky side is exposed, attaching that to one end creating a loop, then in order to break the loop again peel off a little strip. Obviously then I would solder an insulated wire to this and attach this to the earth on the pickup.

Does attaching to the earth at the pickup matter or could I run it all the way to the output jack?

[newey]

It shouldn't matter where you ground it. And leaving the backing tape on is fine.

But sg is right, the discussion we had ended up aligning around the idea just to not go around the coil completely. Whether the wrap touches the coil or not, it will still be affecting (at least potentially)the field around the coil. You do not want the wrapping to make electrical contact with the coil wires, certainly. Most pickups have some tape, or a coating, around the coil so this shouldn't happen, but to be sure, leave the backing on, or use tape to insulate any potential contact.

[rabidgerry]

Nice onE!!

Thanks Newey. This should be easy to do. I wont have to time to do it this since I'm off on a little uk tour but when we get back, I'll get that rickenbacker on the operating table for some surgery.

Just means crappy noisey bass might be heard at our gigs next week lol

I'll photograph guys and post them up once I've completed.

Also I shall record with and without sheilding to alow for tonal comparison

[rabidgerry]

Well better late than never

I did it.











Ok so I rapped some copper tape around the pickup. You can't see it but I removed a strip from this loop so as not to create a complete turn and cause a coil to be created.




created a small earth wire to attach the pickup shield directly to the earth terminal on the pickup. Dabbed a bit of flux on the tape and then just dropped a bit of solder on there and attached the wire which I had already tinned at both ends before hand.












removed the earth wires from al the pots, and even from te selector switch. They already connect to the shield because they are screwed tight against it.



testing the connectivity between the selector switch and the shielding




installed and now put back together. One thins I will add that I did not photograph was the fact that I soldered the earth wire from the trem directyl to the shielding in the control cavity. I just placed a dab of solder flux on the bottom, heated up some solder and tinned the area, then soldered the trem wire to this area. Had to be quick so as not to damage the copper tape.

[rabidgerry]

I only get to test this out on Saturday so lets hope I did a good job and the shielding does what it is supposed to. I feel confident because I did a guitar the same way and it's as quiet as a mouse

[rabidgerry]

I just read on another website

"I would run the shield wire to the main circuit ground. With it soldered to the pup wire any current induced by noise will get into the pup ground wire. Since wires don't have zero resistance you will get a noise voltage on the pickup output.

Rule of thumb: don't mix shield and signal grounds. Keep them separate and ground them at the star point."

This refers to the wire I have on the pickup shield that connects to the pickup earth. It's BS to me though because it all goes to the same place anyways. What do you guys think?

[newey]

Rule of thumb: don't mix shield and signal grounds. Keep them separate and ground them at the star point."

That's a good "rule of thumb", and one that ChrisK made here repeatedly. But it's one of those "best practices" things that may not make much real world difference. I wouldn't worry about it now, just test the Ric and see how your shielding works. If it's good, no reason to redo that connection.

BTW, nice clean install and thanks for the pictorial explanation!

[rabidgerry]

Thanks Newey

so far it does seem good to me (sound wise). It has not been tested however in the enviroment where it was picking up the noise real bad (the bands practice room)

So tomorrow is D Day!! Will report back. I think it will have at the very least helped a bit.

Yeah I skipped a few steps on the photos but I documented it fairly well, glad to post it if it helps anyone else out in the future. I relied on this sorta stuff when I came looking for answers with modding and improving guitars so it's cool to contribute in some way to someone else gaining knowledge

[rabidgerry]

Ok so it didn't work!!!

At least not on the bridge pickup.

The neck pickup which is one of them toaster pickups (i do not know if this is a humbucker or single coil do you know man?) is quiet as a mouse!! Zero noise. The bridge pickup (a single coil) which is the one I applied a seperate shield to is still noisey as hell. No change what so ever. No worse I have to say, just the same.

I have to investigate further. I don't think it will make any difference but I will move the earth wire for the shield and connect it directly to the shielding inside the cointrol cavity. I don't know what else to try. Worst comes to the worst I will install a new pickup. I'd rather solve the issue though!

[studiostriver]

Prepare to say goodbye to high end of your pickup(s). Even shielding just guitar tame highs a little bit,but putting it on pickup it will change the tone to very noticeable level..

Great guitar by the way.I dream of 5 string Rickenbacker someday.

[rabidgerry]

Thanks, its not my bass though. I never liked the red, orange yellow sunburst finish myself. I like the old Rickenbaker bass in plain old black and white.

well in any guitar I have shielded it has never changed the tone at all. And I think a few people on here would debate the loss of treble after shielding the pickup directly.

As I mentioned I have shielded the pickup and there is no difference in either the problem or the sound. Sounds exactly the same as it did before and that includes the noise unfortunately.

[rabidgerry]

I may have missed a few things with this shielding project. I'm going to go over it all again and see if I can improve on things a little.

First off I must reporst that when I tested the bass in the enviroment where it was getting noise it was perfectly quiet when I used the horse shoe humbucking pick. There is no surprise lol Second, when I tested the bass DI'd into my recording unit the noise level was below -40db.

Is the bass actually quiet then after all?

Well I dunno. Few things I wanna try first of all.

The bridge pickup cavity that I shielded is not actually attached to the rest of the shielding in the control cavity!! School boy error there. So I must run a wire from control cavity to pickup cavity to ensure shielding the whole way around the guitar.

Next I might shift the the wire from the actual pickup shielding rap to the main grounding point in the control cavity rather than solder it to the earth signal wire on the actual pickup itself.

Any other ideas for me to try are welcome. I'm not giving up just yet