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Jazz Shielding Pictorial (Big Images Warning)

#141
Thanks, yeah I've heard the "don't do that" advice, as well. I guess what I'm curious about is if it's a result of the circuit pulling the neck pickup ground above ground reference, then everyone who does this mod should have the same result. So, since this is a pretty common mod on this forum, is everyone who did a push/pull serial/parallel mod with a stock Jazz seeing this same behaviour? The question being is this normal, safe behaviour for this particular circuit, and I should just "don't do that", or have I done something wrong that's potentially dangerous and needs to be corrected.
 
#142
ghindman said:
Thanks, yeah I've heard the "don't do that" advice, as well. I guess what I'm curious about is if it's a result of the circuit pulling the neck pickup ground above ground reference, then everyone who does this mod should have the same result. So, since this is a pretty common mod on this forum, is everyone who did a push/pull serial/parallel mod with a stock Jazz seeing this same behaviour? The question being is this normal, safe behaviour for this particular circuit, and I should just "don't do that", or have I done something wrong that's potentially dangerous and needs to be corrected.
Click to expand...
As far as I can tell from what you're saying, you did fine. I've heard of this "hum when you touch the pole piece" before on unmod'd basses. I'll figure out the reasoning behind it someday... just haven't yet. If you do, go ahead and post here... probably something like what you're saying tho... your body probably creates a false ground or something.
 
#143
I just finished shielding my bass as per the instructions here and it seems to have quieted it down a bit, not dead quiet but a nice improvement. The copper foil was much easier to work with than I anticipated.

I put the push/pull DPDT while I was in there and couldn't figure out why the tone control wasn't working when I was done. I had just forgotten to solder a cap in there. Rather than trying to reuse the stock capacitors, I had a .03 uf cap from a previous preamp project that I figured might work ok. It did the job and I am pretty darn happy with the overall results from everything.
 
#146
mariner said:
Foose4string, how much of a difference did you get adding the DPDT switch? I've seen mixed results here in the forum and I'm considering doing it, but wanted to hear more.
Click to expand...

I like the extra volume and thump when I pull into series. It really seems to add a certain presence to the instrument that wasn't there before. I think it will be nice having that feature when playing some of the heavier rock styles and still be able to go back to the standard jazz sound when needed. I've always liked the versatility of the and looks of the J, and this just adds some serious ballz to the sound. I do miss not having a blend control when in parallel mode, you have to adjust the volume on each pickup accordingly. I think wiring the actual Fender S-1 switch remedies this.

Did you mention the year of the bass. I have a 66 and was wondering if the electronics are the same.
Click to expand...

If you were refering to my bass, it is the current Highway 1 model that I bought new this year. It has the stock vintage(passive)pickups, and I'm not sure how much different the wiring is from a 66. I can't imagine it's too much different, I just followed the schematic from another thread.
 
#147
Invalid Link Removed

I am trying to use this wiring schematic, but i want to do star grounding. Which wires would be moved? Should i even worry about star grounding with this schematic? If not where should i wire the lead from the bridge.
 
#148
Linas said:
Invalid Link Removed

I am trying to use this wiring schematic, but i want to do star grounding. Which wires would be moved? Should i even worry about star grounding with this schematic? If not where should i wire the lead from the bridge.
Click to expand...
Remove both black wires from the pickups and solder them to a lug in the cavity. Then take a third black wire and solder it between the output jack (where the bridge pickup ground was connected) and the lug. The plate should ground all the pots and jack together, so you could just remove the common ground wires also connected to the output jack, but if you want a perfect star, just disconnect them from the jack and solder them to the lug as well.. If your bass is fully shielded, then the "ground can" will surround everything, and everything in the ground can will be connected to the ground can from a common point, which will give you a perfect star config.
 
#149
Vic said:
Remove both black wires from the pickups and solder them to a lug in the cavity. Then take a third black wire and solder it between the output jack (where the bridge pickup ground was connected) and the lug. The plate should ground all the pots and jack together, so you could just remove the common ground wires also connected to the output jack, but if you want a perfect star, just disconnect them from the jack and solder them to the lug as well.. If your bass is fully shielded, then the "ground can" will surround everything, and everything in the ground can will be connected to the ground can from a common point, which will give you a perfect star config.
Click to expand...
Will the series/parallel work if he does this, though?
 
#150
Dan1099 said:
Will the series/parallel work if he does this, though?
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Ahhh, wait... my bad... thanks... good catch... yeah, he has to leave the bridge hot and neck ground where they are and instead, just move that entire pot ground bus to the lug as well as the ground pin on the jack and the bridge ground.

Sorry.

Basically, with this config, the switch determines what's grounded, but whatever it is, it should go to the lug... not another component connected to the lug.

In theory, the only diff is the resistance of the soldered connections of the wires, so really it might not matter that much, but for a perfect star config, you want ALL those grounds to go direct to the lug instead of connecting one to another and then eventually to a lug.
 
#151
Vic said:
Ahhh, wait... my bad... thanks... good catch... yeah, he has to leave the bridge hot and neck ground where they are and instead, just move that entire pot ground bus to the lug as well as the ground pin on the jack and the bridge ground.
Click to expand...

Vic, thanks for the response but i am not good with this terminology. Is there anyway you could doctor that pic to show me? What is the pot ground bus.
 
#152
Linas said:
Vic, thanks for the response but i am not good with this terminology. Is there anyway you could doctor that pic to show me? What is the pot ground bus.
Click to expand...
All the ground wires that are connected together.

All the top pins on the pots as well as "A" on the switch are all connected together and then to the output jack, which the bridge pickup ground is also connected to. If all three wires are directly soldered to the output jack and not to a common wire that goes to the jack, then you've already got a star ground except for possibly a bridge ground wire and the shielding.

I say that because everything would be coming off the jack ground pin. However, I'm making the (bad?) assumption there are other grounds in use such as copper shielding, and maybe a ground wire coming from the string bridge, and I'm also assuming the wires from the switch and pots are soldered together and then a common wire goes to the jack.

So, you have a couple options...

Either move everything to a lug screwed into the cavity (which is connected to the shield as a result via the screw) or move the (string) bridge ground wire to also be soldered to the ground pin on the output jack (which is currently the center of the star in what's pictured).

I just generally hate having a million wires connected to the jack, so I tend to run all wires to a lug screwed thru the shield into the body (most Fenders already have it there anyway).
 
#153
like so?
Untitled-2copy.gif
It almost seems easier just to keep it as it is. Is it going to make a difference?
 
#154
Linas said:
like so?
Untitled-2copy.gif
It almost seems easier just to keep it as it is. Is it going to make a difference?
Click to expand...
Almost. Now disconnect the bridge pickup ground and go to the lug, and also add a wire from the output jack to the lug. Basically, ALL grounds need to go directly to the lug.

The diff it will make depends on what, if any, real problem you're having. The whole problem this solves is ground loop hum, based on resistive connections to ground between some things and not others, effectively creating a potential between them.

If you have really solid zero ohm connections everywhere, and you're not actually having a ground problem, this will buy you little or nothing.

I was assuming you were having a problem, and were trying to solve it. This definitely falls under the "if it ain't broke don't fix it" header.
 
#155
just a quick question my new jaguar bass didnt hum when i tried it out in the shop nor when i had it through my practice amp but through my main amp (peavey mkVI circa 84) i get a lot more of hum and buzz when soloing pups.

after reading through this thread im pretty sure i just need to sheild the bass as the strings buzz when i let go and i found the radar technique no buzz sweet spot when playing through the peavey, however when i pulled up the plates to see what i was upagainst i found a nice multi color spagetti of wires (obvious when you consider the pickup on offx2, series/ parallel, active/passive switches and controls plus passive tone).

i was just thinking would the sheilding be enough if i did it without sheilding the cavity channels as i dont want to desolder all of those wires and then resolder them back (i dont mind a common ground taking series switch into consideration).
 
#157
UFF!
I have just domne a shielding job on my P bass!!
I used aluminum foil!
I experimented a lot with the wiering and found it best to remove all the pots!!! I only left the out and pickups!!
WOW!!
the hum/buzz thing is reduced to almost unaudiable but the signal of the bass and tone are 40% increased!!!
I have even instaled a ground lug and wierd the bridge, pu and out to it!
Thanx for this topic cuz I have solved one big problem that has been bothering me since i started playing bass.
 
#159
i_got_a_mohawk said:
Can someone explain star grounding to me?

Is it just using an individual wire for each grounding point, and connecting it to a common point, then to the bridge?

And wiring the ground leads from the pickups straight to the output jacks negative (not hot) lug?
Click to expand...
Almost.

It meants both pickups, the output jack, bridge, and the electronics, are ALL grounded to a common point (usually a lug screwed thru the shielding)... hence a "star".
 

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