Help me put my bass guitar back together

[linda barth]

I guess I don't understand. They are already magnetic. Not as magnetic as the Schecters. What magnets are we putting on the bottom? Do I have them already? I just finished bore out some room for them. If I have the magnets I'd like to put them on and see how it goes.

[Peter Wilcox]

I was assuming, possibly erroneously, that the bag 2 pickups went with the magnets on the brass plate. However, the pole pieces in the pickups may be magnets themselves, in which case you wouldn't need the magnets on the brass plate. So touch a pickup with a (non-magnetized) screwdriver - if it clamps on to a pole piece (the round metal things) with fairly strong magnetic force, then you won't need any outside magnets.

[linda barth]

Before I go crazy looking for a non-magnetized screwdriver, let me tell you that those black pickup/magnet looking things on the bottom of the brass plate are rubber.

so....no magnets....right?

Look what I found. I was looking for ways to sand the bass a little and I found this :

https://www.youtube.com/watch?v=Vk_zewM2JM4

[Bob Gramann]

I don't do a lot of work on electrics, but it seems to me that pickups sometimes have foam rubber underneath them to keep them from rattling in the cavities. It compresses when the pickup height is adjusted.

Personally, I wouldn't sand that bass. Once you remove wood, you can't put it back. It looked pretty nice in the pictures you posted earlier.

[Peter Wilcox]

let me tell you that those black pickup/magnet looking things on the bottom of the brass plate are rubber.

so....no magnets....right?

There are pickups that have rubber magnets. To make sure these aren't magnets, touch a screwdriver to them to see.

To make sure the pickups work as is (without the rubber) you can also hook the meter leads to the solder pads (or wires) on the pickup, set it to DC 10V (hopefully this is sensitive enough - if not, try DC ma 0.5), and sharply touch a screwdriver to the pickup at a pole piece. The meter needle should deflect a little bit as you touch it, and again when you rapidly remove it.

[linda barth]

I touched them with the screwdriver and with an actual magnet....nothing. No movement on the meter at 10. No movement at any setting except the X1K Ohm where it goes to the middle.

Why can't I use my original pickups with the bag 2 stuff?

[Peter Wilcox]

OK, so now we know those are not magnets, just backing pads.

As far as testing the pickups, maybe your meter isn't sensitive enough. Make sure the meter is connected to the pictured leads, and use a fairly large screwdriver (the more iron mass, the better.) Anyway, you really don't need to test them - since the DC resistance is OK, they'll probably work fine.

Maybe you could use the other pickups, but they have 5 or 6 wires coming from them, apparently for use in an active (powered with a battery) system, and we still don't know how to hook them up. I'd suggest you just use the bag 2 stuff for now - it's an easy install, and later you could switch out the active stuff if you can find out how to do it.

Does the bridge have a ground wire hole underneath it?

[linda barth]

I have already removed the bridge. It does have a hole.

I've attached a couple of diagrams

[David King]

Here are the coil cut/volume pot connections for the Schecter P-04 bass pickups. It looks really simple to me and you could accomplish the same thing using a regular push-pull volume switch. You would just need to flip the switch connection from going horizontally to vertically
I'm guessing that a custom Mod pot from Potentiometers.com would cost in the $40-60 range as a minimum to replace the original Schecter pot that broke which is a pretty ridiculous price for a $4 part.

[linda barth]

Is it something I need to buy or is it in one of the bags? Can you send me a picture the part I need.
Are my Schecter bass pickups called P-04?

[David King]

These are the equivalent connections I would make to a regular 250K push/pull switch pot you can buy at any guitar shop.
The white and yellow go to one switch lug.
The red and purple go to the hot side of the pot.
Ground goes to the opposite side of the pot.
Center lug on the pot goes to the output jack.

[David King]

A 250ka push pull pot like this one will do the trick:
https://tubedepot.com/products/alpha-16 ... vQodzqoMiA
You don't have to bother with it at all if you just solder the yellow and white wires together and tape them up. Use one of the other pots you have and wire the red+purple to the left lug and the black to right lug That will give you the pickup at full winding strength which is probably the way you'd want it 99% of the time anyway.

Schecter's 1979 promo literature refers to the pickup as a P-04. Someone has a brochure listed on eBay currently which how I know this.

Also I'd meant to attribute the two photos of the schector switch Mod pot I posted earlier to someone who goes by the name of imdkoz over at talkbass.

[David King]

Oh! I left off the brown wire above but it stays with the black, going to ground on the pot.

Here's what another buddy had to say about these pickups which confirms what the photos were telling us:

bottom half, red is full tap, white is centre tap, black is earth (earth also shields the pickup)
top half: purple full tap, yellow is centre tap and brown is coil end

so hot config is purple to hot, brown to red, black earth
tap config (cool tap) yellow to hot, brown to white, black to earth

these are series config (normal pbass)

for parallel hot

purple and red to hot
brown and black to earth
others disconnected

cool config
yellow and white to hot
brown and black to earth
others disconnected

you could easily have a switch to tap the pup and another switch for series/parallel

[David King]

Updated parallel wiring diagram:

[linda barth]

Someone got crayons in their Easter basket.

Sorry I've been so quiet. I've been redesigning my work space/office for the last two days. Everything got moved including my 6 foot desk which I never thought I could push. I've almost got it all the way I want it. I'm ready to start working on my bass. When can I start guys????

[David King]

We don't know if your husband's bass was originally wired in series or parallel. Most P bases are wired in series though I can't imagine it makes that much difference on a Pbass since no string is getting picked up more than once so no additive effects with series. Someone else who's experimented more and wants to discuss this may do so.
For parallel wiring:
While looking at the volume pot with the shaft pointed down and the lugs facing you, solder the red and purple wires to the left hand lug and the black and brown wires to the right hand ground lug. The white and yellow wires from the pickups are not connected to anything and can be taped off. Connect a white wire (or whatever colored wire you have on hand) to the volume pot's center lug and solder the other end to the jack tip lug. Solder a black or other wire to the jack's ground sleeve lug to the back of the tone pot and from the back of the tone pot to the back of the volume pot. Solder a short jumper from the volume pot's ground (right side lug) to the back of the volume pot. Solder a white or other wire from the center lug of the tone pot to where the red and purple wires are attached to the volume pot. Run a black wire from under the bridge to the back of either pot.
Use the Stewmac diagram you posted above for a p bass as your reference. The two Seymour Duncan basslines diagrams showing two pickups and two volumes are not applicable.

[linda barth]

I don't know the difference in series and parallel. This bass was just given to him by a friend. He never said anything specific about it that I can remember.

I'm doing some sanding on the body now. Then, I want to apply some kind of finish that will let the natural wood show. Any suggestions would be welcome.

Then I'm going to pick one of the diagrams and get started. It's not like we can't make changes later if we don't like the outcome. It's truly a learning experience for me. My soldering skills aren't that good. I may need to practice that a bit.

I

[Rodger Knox]

TrueOil would be a good choice for a finish, I'll give you a little more detail on how to apply it when you're ready.

Soldering isn't that difficult, just remember to heat the work(wires, back of pot, lug on switch) not the solder. When the work is hot enough to melt the solder, you can get a good connection between the two. Be careful not to move anything while the solder is cooling (5 to 10 seconds), that can result in a "cold joint" which looks OK but does not make an electrical connection. Cold joints sometimes look grey, as opposed to shiny silver.

[linda barth]

Thanks. I hope I learn how to solder well.

[David King]

About 15 years ago I put up a little soldering tutorial online. I can't link to it directly by forum rules but you can find it if you search "soldering 101" with google. At least you could 15 years ago... OK I just checked and there seem to be a lot of tutorials coming up including mine. If you prefer youtube videos you would appear to be in luck there too. I'm sure they are all useful to some extent.