I noticed a HUGE difference in my jazz when I shielded it with Aluminum foil. How much better do you think it would be if I used copper foil?
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Jazz Shielding Pictorial (Big Images Warning)
- Thread starter Lyle Caldwell
- Start date
probably not much. Any good conductor does the job. I think the main thing is copper is easier to solder to and a little more durable.momo said:
Sorry - missed this because I was on vacation. But Vic already answered it correctly.
Cardiac95 said:
I attempted this procedure on a J-type bass with vol/vol/tone setup and everything "looked" like it came together well but the sound result was a constant low buzz. I checked all solder points and they seemed solid.
the layout:
shielded all cavities with copper foil tape, P/U cavities conected to control cavity via copper wire soldered to the side wall of the control cavity.
followed this schematic for the pots.
along with lyle's schematic as far as pot grounds terminating to the jack
the only thing I can think of is maybe i used the wrong gauge of wire (i used 18 gauge) which i just eyed to be an okay choice maybe I was wrong about this assumption.
what gauge of wire can you use? what happens if all components are added to the star "grounding lug"?
I plan on trying again this time with a new "jazz bass wiring kit" so new pots and orange drop cap and provided wire.
does anything seem suspect to anyone as far as my current attempt?
thanks
the layout:
shielded all cavities with copper foil tape, P/U cavities conected to control cavity via copper wire soldered to the side wall of the control cavity.
followed this schematic for the pots.
along with lyle's schematic as far as pot grounds terminating to the jack
the only thing I can think of is maybe i used the wrong gauge of wire (i used 18 gauge) which i just eyed to be an okay choice maybe I was wrong about this assumption.
what gauge of wire can you use? what happens if all components are added to the star "grounding lug"?
I plan on trying again this time with a new "jazz bass wiring kit" so new pots and orange drop cap and provided wire.
does anything seem suspect to anyone as far as my current attempt?
thanks
Question. On my geddy lee, I have the copper grounding plate in the bottom of the control cavity. All of the grounds went to the bridge PU pot on the stock bass, including a wire from that grounding plate. I now have ultra Jazzes in the bass, and I wanted to star ground the bass. Can I just remove the copper plate ground wire and ground everything else to the copper grounding plate?
If I understand you correctly, yes. As long as everything is grounded, and as long as everything is grounded only once and at a common point, you should be good.momo said:
Alright, I have some questions, but first off, I have to say excellent job Lyle!
Ok. I have a '91 Heartfield Prophecy. NOTE: the bass is passive w/ a preamp circuit on the pots It has a Blend Pot for the P to J Pickups, Master Volume, Bass Boost/cut, and tone. Problem is (which I've had ever since I bought it) I get a constant hum when I crank the blend 1/2 way to the bridge PUP, but even more when I go all the way.
All ground leads I see are star grounded to the blend. My dad and I have tried different ways to see where it was coming from. We finally concluded it was from the pickup. My dad proposed that we should put a capacitor from the output of the Bridge PUP to the blend pot. I didn't really agree and I thought I should just shield the PUP cavities and the control cavity. Which one do you think would be more effective?
I dont want to change the PUPs, but I may have to do that. Is there any solution where I can at least get rid of a significant amount of that buzz from the Jazz PUP?
Ok. I have a '91 Heartfield Prophecy. NOTE: the bass is passive w/ a preamp circuit on the pots It has a Blend Pot for the P to J Pickups, Master Volume, Bass Boost/cut, and tone. Problem is (which I've had ever since I bought it) I get a constant hum when I crank the blend 1/2 way to the bridge PUP, but even more when I go all the way.
All ground leads I see are star grounded to the blend. My dad and I have tried different ways to see where it was coming from. We finally concluded it was from the pickup. My dad proposed that we should put a capacitor from the output of the Bridge PUP to the blend pot. I didn't really agree and I thought I should just shield the PUP cavities and the control cavity. Which one do you think would be more effective?
I dont want to change the PUPs, but I may have to do that. Is there any solution where I can at least get rid of a significant amount of that buzz from the Jazz PUP?
I don't mean to speak for Lyle, but I know what's going on here...OmegaZ27 said:
This is VERY common for typical P/J configs. What you're dealing with is yer typical single-coil hum from the J pickup. Unlike a J bass, where they humbuck when both pickuts are blended -- because both are single-coils acting as one big humbucker in that position -- on a P/J the P pickup is humbucking all by itself, so it will be very quiet. However, the J pickup is now orphaned so it will always hum.
There are two solutions for this.
One, get a humbucking single J pickup... such as the bridge version of the DiMarzio Model J (to name one of a very many alternatives). It'll wire right in with no mods to the bass at all, and get rid of all or at least the vast majority of the hum. Done.
The other solution requires a lot more work, but will allow you to keep the original pickup, if, for example, you REALLY want to keep the exact sound, or if you want to preserve the original condition of the instrument (I have no idea what one of those is worth).
In this case, you'll need to do all the shielding work outlined in this thread, as well as verifying the ground is a star config (which it should be if it's a really nice bass). My Zon has single-coil pickups in it, and while there's hum when I solo the pickups, it's not bad at all, and it's because of the great sheilding job they do.
So there you have it. No go fix your problem and be happy.
FWIW, my p/j project bass is very quiet with the carvin j99 solo'd. Much quieter in fact than the 2 j/j yamaha's I've done recently with the bridge pup solo'd. (including the one you sold me Vic).
Yeah, those Yamaha's sound good, but they're not shielded that great and they are single-coils. I was gonna' do a shield project on mine, but then GAS struck and I had to move it on down the line.eots said:
Vic said:There are two solutions for this.
One, get a humbucking single J pickup... such as the bridge version of the DiMarzio Model J (to name one of a very many alternatives). It'll wire right in with no mods to the bass at all, and get rid of all or at least the vast majority of the hum. Done.
The other solution requires a lot more work, but will allow you to keep the original pickup, if, for example, you REALLY want to keep the exact sound, or if you want to preserve the original condition of the instrument (I have no idea what one of those is worth).
In this case, you'll need to do all the shielding work outlined in this thread, as well as verifying the ground is a star config (which it should be if it's a really nice bass). My Zon has single-coil pickups in it, and while there's hum when I solo the pickups, it's not bad at all, and it's because of the great sheilding job they do.
So there you have it. No go fix your problem and be happy.
So, the best method would be to shield the bass? I know that the cavity and pickups were shielded w/ shielding paint before because I see some of it rubbed off by the plate contacting the cavity. So do you think that the shielding paint has gone bad and would I have to reshield the cavity? And if I'm going to shield it, would I have to sand out the paint or can I just go ahead and shield over the paint? I dont think I would remove the shielding ever once Ive shielded it.
I'm most likely going to shield the cavities, but I might look into new pickups next year.
What precision pickups are you using for your P/J project? I'm just wondering if they would match the carvin pickups.eots said:
Yeah, I think it's all about a good shield job, and I'm not a huge fan of the paint. I don't think it's conductive enough. It doesn't hurt anything to leave it in place. Just put the copper foil over the top. That's what I did with my Geddy, since I tried the paint first.OmegaZ27 said:
My P pup in my project p/j happens to be out of my fernandes p copy, whoever makes it I don't know. I put a 1/4'er in it and loved it then had this one with nobody to love it. It works well enough in the p/j. I tried a carvin h50n,j99, the yamaha j, and a bart j and the carvin j99 sounded the best in it.
My yamahas, 3 basses and 1 electric guitar all had shielding paint. I checked my BB605 with an ohmmeter at several different points of the shielding paint in the control cavity and to a few metal parts and got high ohms. That didn't seem like a good thing to me so I copper foiled them. It helped much but the 2 Yamaha basses I did still have the solo J hum ( less so than w/o the copper) but I attribute it to the pickups sucking it all in.
The Carvin h50n is already a humbucker so it naturally works so I put a pair in the BB605. The Carvin j99 responded surprisingly well to the shielding and is pert near imperceptible so it stayed in the p/j .
My yamahas, 3 basses and 1 electric guitar all had shielding paint. I checked my BB605 with an ohmmeter at several different points of the shielding paint in the control cavity and to a few metal parts and got high ohms. That didn't seem like a good thing to me so I copper foiled them. It helped much but the 2 Yamaha basses I did still have the solo J hum ( less so than w/o the copper) but I attribute it to the pickups sucking it all in.
The Carvin h50n is already a humbucker so it naturally works so I put a pair in the BB605. The Carvin j99 responded surprisingly well to the shielding and is pert near imperceptible so it stayed in the p/j .
Now what about shielding for a P-Bass style bass (or a Strat) where the cavities are completely open and there is a pickguard? Do you have to apply copper shielding to the entire area that encloses the cavity on the back of the pickguard and how do you ensure a good seal/contact with the cavity?
That's may be the best technically, but on a J, the bridge pickup is totally uncovered, so take that into consideration. I'd think if you can go to shielded cable (which is what I also did), you probably don't have to worry too much about covering the wires in the "ground can".Smallmouth_Bass said:
I just finished shielding the crap out of my MIJ Jazz, and wiring in the parallel/serial mod using this wiring diagram and a push/pull tone pot:
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Now, when the bass is sitting, hands off, it's whisper quiet. Playing, whisper quiet. Both pickups are sending signal with roughly the same relative volume. The push-pull parallel/serial function is working as expected.
But, if I put a finger on the neck pickup pole pieces, I get a nasty ground hum. If I then touch the strings, or bridge, the buzz goes away. The bridge pickup does not do this.
I corrected a potentially bad solder on the neck ground to the push/pull, and that did not change anything. I would think if it were a bad pot, I'd be having some volume issues from that pickup, as well.
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Now, when the bass is sitting, hands off, it's whisper quiet. Playing, whisper quiet. Both pickups are sending signal with roughly the same relative volume. The push-pull parallel/serial function is working as expected.
But, if I put a finger on the neck pickup pole pieces, I get a nasty ground hum. If I then touch the strings, or bridge, the buzz goes away. The bridge pickup does not do this.
I corrected a potentially bad solder on the neck ground to the push/pull, and that did not change anything. I would think if it were a bad pot, I'd be having some volume issues from that pickup, as well.
I'm not totally sure that's a "ground hum". I've heard of this before, and I've heard the solution be described as "don't do that".ghindman said:
If theyre' the large exposed pole pieces, a trick I've heard work well is a little bit of nail polish as an insulator.Bottom line is, I haven't done the research to figure out what you're introducing into the "circuit by connecting your body to the pickup".
