upgrading a Squier "P" bass

[Syco_bass]

I don't know if this topic has been covered or not, I didn't search, but I thought maybe I'd show everyone what I do when a customer asks me what to do when they want to upgrade their P bass.

The first thing I do is take the bass and the body completely apart. Then, I clean out the body cavities with denatured alcohol. I then completely shield the cavities with shielding paint. Like so:

Notice that I purposely bring some paint up onto the surface of the body so that it will make contact with the sheilding tape on the pick guard.

While the body is drying, I get to work on the pick guard and tone circuit. I shield the area where the pickups go and I also make sure that the shield tape goes all the way to the aluminum shielding tape that comes from the factory. If it isn't there, use copper foil for that too.


Be careful, this stuff can cut you like a razor blade.


Then I get to work on installing new pots, tone cap and jack. I only use USA Vintage styl 250K pots with either a PIO, Orange drop or Chiclets style tone cap. On occasion I will use 500K pots if a customer would like a bit of a brighter tone.
Here are the pots in place ready to be wired. Notice that I have pre-tinned all of the lugs on the pots. Also, Squier used smaller 1/4" tone pots. I had to drill larger 3/8" holes in the pick guard for the larger posts. Easily done with a 3/8" drill bit and drill press or a steady hand and a cordless drill.



With those in place, I wire all of my bases with the same cloth covered vintage style wire. Here it is all wired up.


I like to use many different pickups. I don't have a favorite, but at the moment, I really like the products being put out by Tesla pickups. Check out these Phat 60's vintage style P bass pickups. They are built using high quality parts, with heavy gauge copper windings and vintage style cloth covered leads.


Once everything is wired, I re-assemble everything and check for hums, pops, etc. before re-installing the neck. BTW, check out the new control knobs.



This bass will not only sound better than the original Squier components but it will be much less susceptible to problems down the road.
Hope this was helpful.

Cheers.

[Pilgrim]

Very nice, neat work!

[FutureTense]

I always like seeing how people go about doing work on equipment. Nice job!

[Muckaluck]

Wish this was around when I upgraded my Squier P. The pictures are very helpful. Great work.

[Turnaround]

Good job generally, but you may have introduced a ground loop. Assuming you wired the pickups so that the ground from the pickup is soldered to the back of the pots, you then have a ground path through the wires on the back of the pots to the output jack as well as one through the shield. That's assuming that you didn't isolate the pot mounting shaft and the jack mount from the shield. It's not a big deal, but it's not ideal.

[Syco_bass]

Originally Posted by Turnaround

Good job generally, but you may have introduced a ground loop. Assuming you wired the pickups so that the ground from the pickup is soldered to the back of the pots, you then have a ground path through the wires on the back of the pots to the output jack as well as one through the shield. That's assuming that you didn't isolate the pot mounting shaft and the jack mount from the shield. It's not a big deal, but it's not ideal.

That's an interesting observation turnaround, how would you solve the problem? I am always willing to learn better techniques. Thanks.

[Turnaround]

There are two options really. You could remove the wires connecting the pot bodies to the jack. Since the pots are already grounded to the jack by the shielding foil, you will not be interrupting the ground plane, simply removing the loop.

The problem with this option is that the ground path through the foil will also be the signal ground, and the foil is probably not the best for this. So the second option is to cut the foil away around the pots and the jack so that no part of the body of either touches the foil. Then make all of the ground connections to one single point. So, for instance, the tabs on the pots that are soldered to the back of the pots should be unsoldered from there and attached to a single lug that is anchored to one spot on the shield. The pickup signal ground leads should also connect to this lug along with the bridge ground wire and finally the signal ground from the jack. The goal is to have only one route to ground from each component and only one ground connection to the shield.

That's the way I do it, but I tend towards overkill.

[Syco_bass]

Good discussion here turnaround. I appreciate you sharing your experience. Although I haven't had any issue using the method I illustrated, I see your logic. Couldn't the same thing be accomplished by simply cutting away the foil under the pots/jack area then running one contiguous wire connecting the pots, to the jack, then to a the ground lug? The bridge ground wire could then either be connected to the ground lug or to one of the pots, or even directly to the jack it's self.

So here is another question. What would you do if this were a Jazz bass and we had a chrome control plate? How do you isolate the pots in that situation? Or in the case where we have a rear routed body and the control cavity has been completely sheiled using sheilding paint?

Thanks again for sharing.

[Syco_bass]

O.K. so I decided to upgrade the bridge and the pick guard on this project so while I was doing that, I decided to try some out some different methods for grounding.

First, I isolated the pots using rubber O-rings. This will ensure that the signal ground does not travel through the shielding.



Next I soldered a piece cloth covered wire to a grounding "lug". This is just an ordinary crimp type connector found at ACE hardware. I removed the plastic on the end crimped the wire securely then added a dab of solder for good measure.



After completing the procedure I secured the ground wire/lug to the body using a small pick guard screw. I then soldered the ground wire to the volume pot to complete the circuit.



I admit I was skeptical about how much better this method was going to be compared to the original method. I have to admit that the static noise, even though was low, is completely nonexistent and undetectable what so ever now.

This method has proven to me to be superior and will now be employed on every bass I upgrade or build.

Thanks for the suggestions Turnaround.

[Syco_bass]

Now that I am looking at the wiring in the photos, I guess I could have gone one step further and soldered the ground wire from the pickup to the ground lug as well, thereby cleaning it up a bit more. I am not detecting any static what so ever on this instrument at this time, so I will leave it alone for now. However I will continue to refine.

Thanks for looking. Comments are certainly welcome.