Jazz Shielding Pictorial (Big Images Warning)

[mixx80]

Not trying to Hijack anything but you can check out my pics on this subject.
http://www.talkbass.com/forum/f38/new-jazz-bass-sheilding-ground-warning-lots-pics-811826/

 

[guy n. cognito]

I've now performed this technique on a bass with great results. The one thing that has surprised me is how many luthiers / techs have no idea that this can work if done correctly. The first tech at a local shop told me that it was useless and that nothing could be done to eliminate the grounding hum. Another tech (this one is world renowned and located here in Nashville) resorted to name-calling and insults when I asked him to do this on one of my basses. He made it very clear that the technique didn't work and no experienced luthier would waste his time doing it.

After I completed the work on my bass, I took it back to his shop to show him my work and to prove shielding / grounding was functional. He was somewhat respectful, but still told me that it didn't work and I just "got lucky."

 

[mixx80]

I've now performed this technique on a bass with great results. The one thing that has surprised me is how many luthiers / techs have no idea that this can work if done correctly. The first tech at a local shop told me that it was useless and that nothing could be done to eliminate the grounding hum. Another tech (this one is world renowned and located here in Nashville) resorted to name-calling and insults when I asked him to do this on one of my basses. He made it very clear that the technique didn't work and no experienced luthier would waste his time doing it.

After I completed the work on my bass, I took it back to his shop to show him my work and to prove shielding / grounding was functional. He was somewhat respectful, but still told me that it didn't work and I just "got lucky."

It might not work for everyone but this is the third bass that I have done and one was a Jag. All with great results !! I'm waiting for more copper tape so I can ground the P.U. covers Properly but the bass is quiet so it might be overkill ! I dont know if the paint is coming in contact with the screws and cover enough to make it to ground. I might not even need to go that far I Guess I got lucky also !

 

[scotch]

I've now performed this technique on a bass with great results. The one thing that has surprised me is how many luthiers / techs have no idea that this can work if done correctly. The first tech at a local shop told me that it was useless and that nothing could be done to eliminate the grounding hum. Another tech (this one is world renowned and located here in Nashville) resorted to name-calling and insults when I asked him to do this on one of my basses. He made it very clear that the technique didn't work and no experienced luthier would waste his time doing it.

After I completed the work on my bass, I took it back to his shop to show him my work and to prove shielding / grounding was functional. He was somewhat respectful, but still told me that it didn't work and I just "got lucky."

I had great results as well with the Jazz Bass I shielded!

It seems a lot of techs and repairmen aren't 'hip' to cooper shielding. Perhaps it is less effective on guitars? I dunno,... sure worked great on my bass!

The one experienced tech that I'm really tight with told me to try it, but that it isn't always consistently effective. ? Only more time & shielding jobs will tell!

 

[Vic]

The one thing that has surprised me is how many luthiers / techs have no idea that this can work if done correctly. The first tech at a local shop told me that it was useless and that nothing could be done to eliminate the grounding hum. Another tech (this one is world renowned and located here in Nashville) resorted to name-calling and insults when I asked him to do this on one of my basses. He made it very clear that the technique didn't work and no experienced luthier would waste his time doing it.

After I completed the work on my bass, I took it back to his shop to show him my work and to prove shielding / grounding was functional. He was somewhat respectful, but still told me that it didn't work and I just "got lucky."

Nothing worse than someone in a position of authority being a belligerent ignorant. This is absolutely BASIC electrical stuff, and it should be amazingly obvious to anyone willing to spend any time at all considering it that it really works. It blows my mind that anyone would consider opposition to it defensible... because it's not.

 

[guy n. cognito]

Nothing worse than someone in a position of authority being a belligerent ignorant. This is absolutely BASIC electrical stuff, and it should be amazingly obvious to anyone willing to spend any time at all considering it that it really works. It blows my mind that anyone would consider opposition to it defensible... because it's not.

Well, I wouldn't call it a position of authority. Actually, he lost out on a couple hundred dollars in revenue because of his position. Pretty ignorant on his part. That said, I have yet to find a tech in the Nashville area that will do this work.

 

[Vic]

Well, I wouldn't call it a position of authority. Actually, he lost out on a couple hundred dollars in revenue because of his position. Pretty ignorant on his part. That said, I have yet to find a tech in the Nashville area that will do this work.

What I meant by that is, people who don't know any better (clearly not talking about you here) would consider him to be an authority on the matter since it's his profession. They'd tend to take his (incorrect) comments as gospel and just put up with something they shouldn't have to.

Any time you're generally considered to be a subject matter expert, you're in a position of authority.

IMHO

 

[JimmyKickButt]

Gentlemen, I need your help. This may have already been covered else where, & if it is a redirect would be great...

Anyway, I'm on the tail end of refinishing a Geddy Lee body, and I want to shield it, but I also want to install a push/pull pot for series/parallel. At this point, I realize this may be outside of the realm of this thread because as far as I've seen it's been for standard jazz wiring. The wiring with the push/pull pot seems different/contradictory to the wiring recommendations for shielding. What are your ideas?

 

[bassbenj]

I had great results as well with the Jazz Bass I shielded!

It seems a lot of techs and repairmen aren't 'hip' to cooper shielding. Perhaps it is less effective on guitars? I dunno,... sure worked great on my bass!

The one experienced tech that I'm really tight with told me to try it, but that it isn't always consistently effective. ? Only more time & shielding jobs will tell!

Some confusion is understandable because not many are hip to the fact that there are two kinds of hum. There is the normal electric or "grounding" hum which is the standard "hum goes away when I touch the strings thing" and then there is magnetic hum which is also called "single coil" hum which is common on Jazz basses when you single either bridge or neck pickup. Copper shielding ONLY eliminates grounding hum. Single coil hum requires changing to a humbucker (like Fender "noiseless") pickup. Copper shielding will NOT eliminate "single coil hum". But in my experience, if you take time to shield a bass and eliminate all the usual hum, the single coil hum that is left always seems to be much less objectionable to me.

And since guitar amps usually have severe bass roll-off hum is much less of a problem with guitars than basses. Not no problem mind you, but much less. For this reason shielding is often neglected in guitars much more than it should be. It still makes a difference!

Even though my Fender V deluxe was shielded with conductive paint, it still had a bit of hum. why? I don't know, but in my experience sometimes conductive paint works like a champ and every now and then it doesn't. So I copper foiled it. It already had "noiseless" pickups so single coil hum was no problem. And the copper foil treatment just totally eliminated that last bit of annoying hum. There was not much hum there, but I was surprised that somehow without even that tiny bit of hum, the bass just seemed to sound so much better!

PS. I often use the eraser on the end of a standard pencil as a "burnishing tool" to fit the copper to the cavities and get the glue to stick well. And if you need something harder any plastic rod with a rounded end seems to do a good job.

 

[bassbenj]

Gentlemen, I need your help. This may have already been covered else where, & if it is a redirect would be great...

Anyway, I'm on the tail end of refinishing a Geddy Lee body, and I want to shield it, but I also want to install a push/pull pot for series/parallel. At this point, I realize this may be outside of the realm of this thread because as far as I've seen it's been for standard jazz wiring. The wiring with the push/pull pot seems different/contradictory to the wiring recommendations for shielding. What are your ideas?

I think what is bothering you is that when you wire pickups in series, what used to be the "ground" of one pickup is then wired to the "hot" of the other pickup. This is a normal series wiring. You do however, have to make sure that the "signal return" wire in the pickups you are using are not wired to ground inside the pickup. You have to make sure that both sides of the coil are independent and not connected to any "grounding plates" or shielding! The pickup then should have or be wired with a separate ground wire for all shielding and grounding plates.

G&L MFD pickups in particular always have to have the grounds separated this way if you want to put two in series. Jazz pickups vary and may or may not need the mod. If the pickup has two wires and no grounding plate, you don't need to worry, but then the pole pieces float and can introduce hum. So standard shielding is to shield bottom and sides of pickup cavity and run a piece of copper tape (conductive glue) down the bottom of the poles to ground them too. All shielding connects to star ground but the "signal return" on the pickup coil does not.

The bottom line is that doing a proper shield job on a bass with a series/parallel switch is a bit more tricky than the standard pickups in parallel wiring.

 

[Five String]

Here are some tips on shielding/rewiring a Squier VM Jazz fretless from someone who had not previously held a soldering iron. In no particular order:

1. John Planetz has some excellent videos on soldering guitar pots on Youtube.

2. Use .032 solder. I sarted with .050, then bought the .032 and used it exclusively.

3. I got a Weller Marksman 40 watt iron because of the good reviews online. Comes with 3 tips, I found it quite good.

4. I recommend a 40 watt iron. I do not know how anyone can solder the backs of the pots with anything less.

5. For practice, desolder and rewire your old pots the way you're going to do the new ones.

6. When soldering the new pots, be careful which way the leads are pointing. I did mine a little askew and stuffing all the wires back in the control cavity was a little bearish.

7. CTS pots will not fit in your old Squier control plate. They're too big. You have to drill out the old control plate or buy a new one. 1/4" drill bit did it.

8. Your old knobs will not fit on the CTS posts, you will either have to replace the knobs or drill out the old ones. I chose drilling (15/64" drill bit) and knobs are sufficiently secure.

9. Unless you think you're fairly handy and you are willing to take the time, consider taking the instrument to a music shop to have the work done. It's probably cheaper $$$$-wise to do it yourself but definitely not time-wise.

10. You are not going to entirely get rid of the hum. It's the nature of the single coil. If you still get some hum when you run just one pickup, that's normal.

11. I found tinning my soldering tip tricky. I always ended up with too much solder and crud and found Radio Shack soldering tip tinner/cleaner a great solution.

12. Maybe because I'm a newbie, I found I had much better results when I cleaned the tip with a sponge and re-tinned with the tip tinner/cleaner BEFORE EVERY SOLDER, even stuff like tinning wires.

13. The tiny copper wires on the pickups really scared me so, rather than desolder and re-attach, I just cut the old wires and connected the new ones about an inch or so down.

Except for the normal single coil hum, my bass is MUCH quieter, new pots provide a juicier sound, absolutely worth doing. The loud hum when I took my hands off the strings is gone.

I'm still getting some fairly quiet hum when I play, so I will have to do some reading on this thread and perhaps troubleshooting. If anyone can give me any input on removing that hum, let me know. Thanks.

 

[Vic]

Here are some tips...

Wow. GREAT POST!

I also use flux to help solder flow and look nice, preferably water soluble, for easy clean up with a damp paper towel. Yes, the solder you should be using for electronics has flux in its core, but I like the results I get when I use a little bit more. Not absolutely necessary, just kind of a personal pref, dates back to my many years as a PCB rework guy long ago.

 

[Five String]

Thanks, Vic, your many posts on thios thread were a big help to me and , I'm sure, to many others.

 

[Five String]

I recently replaced the stock pots and wiring on my Squier VM fretless Jazz with 500k CTS pots and re-did all the wiring, as well as copper-shielded all cavities. I took the bass for its first test drive with my band the other day and what a difference.

No, I still had a single coil hum, (house wiring, I think) but the sound quality of the instrument was really improved. Brighter, deeper, louder, more character, more defnition, more clarity, cut through the mix better, lows were lower, highs higher, mids ... midder.

And that's saying a lot since I liked the sound of the instrument quite well before that.

If you can, replace the pots and wiring on your Squier Jazz, it really brings out the tone fantastically well.

Here's the wiring plan I used, a Fender Jaco fretless (MIA?)
[Invalid or Expired Link Removed]

 

[Vic]

I recently replaced the stock pots and wiring on my Squier VM fretless Jazz with 500k CTS pots and re-did all the wiring, as well as copper-shielded all cavities. I took the bass for its first test drive with my band the other day and what a difference.

No, I still had a single coil hum, (house wiring, I think) but the sound quality of the instrument was really improved. Brighter, deeper, louder, more character, more defnition, more clarity, cut through the mix better, lows were lower, highs higher, mids ... midder.

And that's saying a lot since I liked the sound of the instrument quite well before that.

If you can, replace the pots and wiring on your Squier Jazz, it really brings out the tone fantastically well.

Here's the wiring plan I used, a Fender Jaco fretless (MIA?)
[Invalid or Expired Link Removed]

Yeah, you'll never get around SC hum, but a good shielding job WILL reduce it some, which is always nice.

Secondarily, I've actually just recently learned about the significant tonal impact of a proper bridge ground, so if you had any issues with it before that were fixed by your rewiring, that would explain it. I knew about the noise issues, but didn't know about the tonal impact until watching the plantetz vid (btw, check out his other stuff too... he's REAL good).

Check it out!

Guitar Ground: Dealing with ground noise problems - YouTube

 

[Five String]

Hi Vic - How coincidental that proper grounding affects tone. When I pulled the bridge off my Squier the grounding wire was just floating around under the bridge. No tape, no solder, nothing. I wanted to solder it on but I felt like my little 40 watt was not going to work on a big hunk of metal like that, so I taped it on with copper foil with conductive adhesive.

Interesting that proper grounding has an impact on tone. I was hoping I'd just get rid of the hum but what really impresses me about rewiring and trying to get really good solid connections is the improvement in tone. I'm pumped to pop open the back of my old Ibanez SR495 and see what I can do.

I will definitely check out the videos you linked to.

 

[Vic]

Hi Vic - How coincidental that proper grounding affects tone. When I pulled the bridge off my Squier the grounding wire was just floating around under the bridge. No tape, no solder, nothing. I wanted to solder it on but I felt like my little 40 watt was not going to work on a big hunk of metal like that, so I taped it on with copper foil with conductive adhesive.

Well, FWIW, it does not need to be attached. All you need to do is sand off any plating/finishing on the bottom of the bridge and make sure nothing but bare/stripped bridge ground wire is laying under it when you tighten it down. The pressure of the bridge being tightened down should be plenty to assure a good connection. Just of course make sure the wire rides up enough to be pinched, but not raise the bridge up any (don't twist the wire). The "trick" is you want that wire to be firmly pressed on, but not enough to corrupt a nice full bridge surface contact (for optimal string coupling with the body).

 

[Five String]

That's fair, but it was pretty hard to tell whether any of that had been done. I have an old 1978 MIA Jazz and the hum out of the Squier was louder than that. I put the copper tape on the ground wire to make double sure I was getting a good connection.

 

[Five String]

Hey Vic - If you're still minitoring this thread, check out this post I found over in the Himass v. Vintage Bridges thread in the Hardware section. (post #53) I was thinking about what you were saying about the ground wire under the bridge.

"Hello guys!

I just wanted to share some helpful discoveries I made with the Fender vintage bridges.......it may sound very dumb,....but it can help with some peoples addiction to swaping bridges!

I´ve owned a lot of Fender basses and always noticed a somehow anemic sound with the G string, while the rest of the strings sounded tight and focused. I always ended up changing bridges (Hipshot, Badass....) which fixed the problem but gave the basses a different sound....which I noticed...

Last year I decided to make myself a jazz bass out of Warmoth parts and I used a Fender vintage bridge also. I followed a step by step clonation of a jazz bass I had, same wiring procedure....and same thing hapened.

What happens is that the Fender bridge plate flexed upwards not against the body, leaving the G side with an almost paper size gap between the body and the plate. Brought it to my luthier and he fixed the problem drilling two holes in the upper corners of the bridge plate and fixing it to the body with two more screws. Problem solved!

...but I realized that it´s not suposed to be like that.....so I took the bridge out to check out why it was not laying flat against the body.

I realised that the tip of the ground wire under the bridge (which is always bent to the G side so it makes an anchor anle) was giving enough space to lift the bridge up on the G string side...eventhough the bridge screws where puting all the pressure against it!!!!!

I checked out my other Fender basses.......same thing happened! So I just took the tip of the wire, and bent it to the side of the bottom, directed to the screws right in the middle of the bridge. Now the plate was laying right flat against the body!!!! Restringed and.....voilá!!!! Now it sounded great!!!

How dumb I was!!!! Did the same thing with my other Fender basses and...hey...G string is back!!!!

Just wanted to throw some help to those who find problems with these bridges.....they are great! Just, check out twice before you swap bridges cause chances are that this might be happening to yours. I´ve helped a couple of friends with the same problem, and they are happy as they can be!!! Always doublecheck that the bridgeplate is laying totally flat against the body...it´s supposed to do the work!"



I have definitely noticed a gap between the bottom of my brige and the surface of the wood on my old 1978 MIA Jazz. Wondering if the improved tone on my Squier results in part from the bridge now laying nice and flat.

 

[Vic]

Hey Vic - If you're still minitoring this thread, check out this post I found over in the Himass v. Vintage Bridges thread in the Hardware section. (post #53) I was thinking about what you were saying about the ground wire under the bridge.

...

I have definitely noticed a gap between the bottom of my brige and the surface of the wood on my old 1978 MIA Jazz. Wondering if the improved tone on my Squier results in part from the bridge now laying nice and flat.

I'm a firm believer that a solid bridge coupling is important to great tone, so it could be. Remember, back in those days one of the first things folks did was upgrade the bridges on those basses... the most popular being the LQ Badass, of course, and those use the same bolt-holes, too. There were other options of varying designs, but the goal was the same... more mass, and a tighter more solid coupling with the body. Definitely improved things.