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Wiring stacked volume/tone pots.

Delta_Petra

Delta_Petra

Feb 26, 2008
662
7
Portland, OR
#1
Hey all.

Please help a wiring newbie.

Just curious if anyone has any experience with this sort of thing. I plan on taking my p-bass project and adding a MM humbucker in the bridge position. I then want to use two stacked volume/tone pots to individually control the p-bass pup and the MM humbucker. Is it just as easy as wiring the pups individually to each pot and then taking leads from each pot to the input jack?

I have looked on ebay and see some 250k and 500k pots that are stacked. Which should I get for this project? Or should I get the 250k for one pup and 500k for the other? And in that case which pup gets which rating?

Here is the bass in question.

IMAGE_174.jpg

 
#3
Here's a stack pot wiring diagram. It's made for a '62 jazz bass but it applies to what you want to do:

[Invalid or Expired Link Removed]

As far as values go, the 250/500K (250K for the top volume knob, 500K for the bottom tone knob) stacked pots are the standard way to go, though the values you choose are mostly personal preference.
 
#4
There are two problems with the setup.

First off, adding volumes and tones to the circuit will cause you to lose output and treble on the P pickup.
If you want to keep your regular P bass tone, i would recommend a pickup selector switch so that you can defeat the extra controls.

However, if you had 250K pots on your bass to begin with, using 500K's would give you the same tone, so you may not need the switch.

The second problem is that with 2 tone controls, any time the pickups are running at an equal volume, one tone will affect both pickups. The tones will only be independent of each other when you have the pickups at different volume settings.
 
#5
line6man said:
There are two problems with the setup.

First off, adding volumes and tones to the circuit will cause you to lose output and treble on the P pickup.
If you want to keep your regular P bass tone, i would recommend a pickup selector switch so that you can defeat the extra controls.

However, if you had 250K pots on your bass to begin with, using 500K's would give you the same tone, so you may not need the switch.

The second problem is that with 2 tone controls, any time the pickups are running at an equal volume, one tone will affect both pickups. The tones will only be independent of each other when you have the pickups at different volume settings.
Click to expand...

So would two 500k pots be the way to go? I can deal with the tone issues as I normally don't have the pickups at equal volume.
 
#7
Awesome.

So should I still use the same .03 and .05 caps from the Fender jazz diagram? Or do I use the same rated cap for both?

I am completely new to this soldering/wiring thing. It is pretty much the last piece of the bass puzzle I haven't figured out yet.
 
#8
Delta_Petra said:
Awesome.

So should I still use the same .03 and .05 caps from the Fender jazz diagram? Or do I use the same rated cap for both?

I am completely new to this soldering/wiring thing. It is pretty much the last piece of the bass puzzle I haven't figured out yet.
Click to expand...

Capacitor value is your preference.

The 0.05uF and 0.03uF you mentioned are for a Jazz bass setup...

Personally, i would stick with a 0.047uF for the P bass, but i don't know what MM pickups sound best with, as i have never tried a MM.

I would probably stick with a 0.047uF.
If that isn't cutting enough for your taste, try a 0.1uF.
If 0.047uF is too much cut, try a 0.022uF.
FWIW, IME with 0.022uF capacitors, they don't seem to have enough power on Jazz basses.
 
#9
line6man said:
Capacitor value is your preference.

The 0.05uF and 0.03uF you mentioned are for a Jazz bass setup...

Personally, i would stick with a 0.047uF for the P bass, but i don't know what MM pickups sound best with, as i have never tried a MM.

I would probably stick with a 0.047uF.
If that isn't cutting enough for your taste, try a 0.1uF.
If 0.047uF is too much cut, try a 0.022uF.
FWIW, IME with 0.022uF capacitors, they don't seem to have enough power on Jazz basses.
Click to expand...

See this is why Talkbass is so helpful. I have no clue about caps and pots and what exactly each piece brings to the sound. So I appreciate your help.
 
#10
Stacked pots and wannabe MM humbucker pickup came in yesterday from ebay. Waiting on a new bridge and then I will start assembling the pieces and routing the body.

I did notice that the wires coming from the humbucker are different than I was expecting. Some I can figure out where they need to go, but one I am unsure of. I will post pics for help later today.
 
#11
Alright, I got my parts in from ebay and am getting ready for this project. Now that I have the parts I realize some things look a little different than expected and not sure how they will compare with the 1962 Jazz Bass wiring diagram.

Can anybody check out these pics and tell me whats up?

Stacked Pots:
DSC01108.gif

DSC01109.gif

DSC01110.jpg

DSC01111.jpg


Wannabe MM Humbucker Pickup:
DSC01112.jpg

DSC01114.jpg

DSC01115.jpg


Here is what is looks like attached to the pickguard:
DSC01116.jpg


And Pickup placement:
DSC01119.jpg



So tell me whats going on with the pup wires and how do they compare with the diagram? My guess is the white/red grouping will go with the white leads in the diagram and the black/green grouping will go with the black leads in the diagram. What about that third wire? Is that the ground to the bridge?
 
#12
Delta_Petra said:
Alright, I got my parts in from ebay and am getting ready for this project. Now that I have the parts I realize some things look a little different than expected and not sure how they will compare with the 1962 Jazz Bass wiring diagram.

Can anybody check out these pics and tell me whats up?

Stacked Pots:
DSC01108.gif

DSC01109.gif

DSC01110.jpg

DSC01111.jpg


Wannabe MM Humbucker Pickup:
DSC01112.jpg

DSC01114.jpg

DSC01115.jpg


Here is what is looks like attached to the pickguard:
DSC01116.jpg


And Pickup placement:
DSC01119.jpg



So tell me whats going on with the pup wires and how do they compare with the diagram? My guess is the white/red grouping will go with the white leads in the diagram and the black/green grouping will go with the black leads in the diagram. What about that third wire? Is that the ground to the bridge?
Click to expand...

The bare wire goes to ground.
Use one set of wires as the hot and the other as the ground.
If it sounds ok, cool, but if it sounds thin and nasaly when combined with the P pickup, then flip the wires around the other way.
You won't do any harm if the pickup is wired backwards.
 
#13
What I was wondering is based on the 1962 Jazz bass wiring diagram with the stacked pots I noticed that it is ground to the bottom of the pots, but the stacked pots that I have don't have a flat bottom.
Does anybody have any insight? Or will the stacked pots I got even work for this project?
 
#14
Delta_Petra said:
What I was wondering is based on the 1962 Jazz bass wiring diagram with the stacked pots I noticed that it is ground to the bottom of the pots, but the stacked pots that I have don't have a flat bottom.
Does anybody have any insight? Or will the stacked pots I got even work for this project?
Click to expand...

The back of the pot is usually the easiest place to ground something, but you can ground anywhere you want to, just so long as you have good continuity.

Just run the grounds to the output jack's sleeve terminal.

Example:
3172360293_80c29e16cd.png
 
#15
Well I am getting closer to finishing this project. I have a friend working on the routing of the pickup, but I noticed that the wiring diagram I once had for the stacked volume/tone pots is a bad link. Anybody have a new diagram for a 1962 Jazz bass with stacked pots? The Fender link doesnt work anymore.
 
#17
Its been awhile, but I am back on this project and taking strides. Those first stacked pots I got sucked, at least as far as me being able to successfully wiring the pickups with such small connections. So I got the Fender stacked pots instead and have been stalling those tonight...

one problem...

I have them wired like the 1962 Jazz schematic, but the pickups are fighting for control. Whichever volume pot is turned up more takes the ENTIRE signal, there is not blending the two pickups together. Is this how the '62 Jazz was designed? Or should it actually be blending the two pickups?

If it doesn't work that way they I will just go for vol/vol/tone for the whole setup.

Blah, I hate when things don't work the first, second, third, or forth time. Been getting this thing ready for months and still haven't been able to really play it like I want.
 
#19
It sounds like you must have something connected wrong. If it was wired exactly line line6's diagram, there should be no problem. I can't really think of what might have gone wrong, but.....well I guess the only advice I can give is look over it again.
 
#20
Delta_Petra said:

one problem...

I have them wired like the 1962 Jazz schematic, but the pickups are fighting for control. Whichever volume pot is turned up more takes the ENTIRE signal, there is not blending the two pickups together.
Click to expand...
this could be a result of my favorite topic apparently, which is audio taper vs. linear taper on the volume pots. linear taper pots will allow for more control over that point where "two pickups" just begins to fade into "one pickup".

also, if you're running these without any preamp, that MM pickup may benefit from a re-wire. judging by the picture, as it came, the leads were wired for parallel operation, which is fine when you have a preamp to boost back the missing low end. you might want to reconfigure it for series, which will sound a lot fatter, especially for a passive bridge pickup. you'll have to undo both pairs, and then use a meter to determine which wires are the start and end of each coil. (that will be two wires that show a resistance of maybe 3-4kohms between them, the other two wires the same, and no connection shows between one pair and the other pair.)

once you have that figured out, attach a wire from one pair to a wire from the other pair, then use the two leftover wires as hot and ground. if it hums, reverse the wires from one pair. if the whole thing sounds thin and weird with the other pickup, reverse the hot wire with the ground wire.

the bare stranded wire always goes to ground no matter what.
 

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