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Wiring Help needed -- Peavey T-40 pickups

S

stevellss

Aug 13, 2008
89
2
#1
I just got a set of Peavey T-40 pickups that I am installing into an SX jazz bass (should be a fun project) and I wanted to do a few modifications to the wiring compared to a standard T-40. I want to check if any of these ideas could be problematic or useless and furthermore if someone could make a simple diagram for me. I have wired up several basses from existing schematics, I just haven't figured out how to lay out the wiring routes myself... any help would be greatly appreciated.

here is my initial plan:


2 vol/2 tone - series parallel switch - individual coil tapping switches.


I chose this way because I have a T-40 and the one thing I don't like is the way you can't have fully open tone in humbucking mode -- but I am also wondering if that is just how the pickups inherently work... would the tone knobs still switch them between single/ humbucker, thus making the switches useless?
Secondly, I rarely use the 3-way toggle switch and the phase switch I can do without, so I thought to make it a little different by implementing a series parallel switch.

lastly, if someone would be so kind as to make a little drawing for me, I'd like to point out that I do not plan on using push/pull pots, but switches instead because I always accidentally push the knobs down!


thanks
 
#2
I believe the coil-tapping on a T-40 is due to the wiring, not the pickups themselves. I believe your wiring plan would work. If you look online most aftermarket pickup companies will have wiring diagrams. I always found Dimarzio's to very helpful. You probably should look up a les paul diagram, what you want sounds similar, you would just change the capacitor value.
 
#3
I can draw you a diagram.

Are you mixing up coil taps for coil splits though?
Not many pickups on the market are tapped.

Assuming a coil split, what configuration did you want?
Series/Parallel, Series/Single Coil, Parallel/Single Coil, Series/Single Coil/Parallel?

You're aware that the 2 tones will only be functional when the pickups are at different volumes, right?
 
#5
line6man said:
I can draw you a diagram.

Are you mixing up coil taps for coil splits though?
Not many pickups on the market are tapped.

Assuming a coil split, what configuration did you want?
Series/Parallel, Series/Single Coil, Parallel/Single Coil, Series/Single Coil/Parallel?

You're aware that the 2 tones will only be functional when the pickups are at different volumes, right?
Click to expand...

Yes, I think maybe I am mixing up coil tapping with coil splitting -- I want to switch from humbucker to single coil. What exactly is coil tapping then?

As for the configuration, I could use some advice. Is it possible to change both from series to parallel at the same time? Would it be wiser to use 2 switches so that each pickup can be switched? I put series/parallel switches in a bass with dimarzio model J's and I have found that I often have them either both in series or both in parallel and so if possible I'd like one switch to change them both.

I am not sure about the difference with tones and the 2 volumes either, I know this is an issue with a phase switch, how does it affect series/parallel?


thanks for the help!
 
#6
stevellss said:
Yes, I think maybe I am mixing up coil tapping with coil splitting -- I want to switch from humbucker to single coil. What exactly is coil tapping then?

As for the configuration, I could use some advice. Is it possible to change both from series to parallel at the same time? Would it be wiser to use 2 switches so that each pickup can be switched? I put series/parallel switches in a bass with dimarzio model J's and I have found that I often have them either both in series or both in parallel and so if possible I'd like one switch to change them both.

I am not sure about the difference with tones and the 2 volumes either, I know this is an issue with a phase switch, how does it affect series/parallel?


thanks for the help!
Click to expand...

Some pickups are wound with a tap part way through the coil wind. Using only a portion of that coil rather than the full winding is a coil tap.

You can use a single switch to change the coils on both pickups from series to parallel if you want. You will need a 4PDT toggle switch in order to do so.
Personally, I think you would be better off with separate switches though, as that would give you more tonal options, but it might be more convenient to you to have both pickups on one switch.

Due to the nature of the passive wiring with two tone controls, any time you run the pickups at equal volumes, it puts the tone controls in parallel, so the one with the lower setting is going to affect both pickups.
For that reason, having two tones is not very useful unless you are always running the pickups at different volumes.

You said in the first paragraph that you want to switch from humbucker to single coil, but then you go on to series/parallel switching in the next paragraph...
Which do you want?
Or perhaps you would be happier with Series/Single Coil/Parallel switching? You can use an On-On-On switch to get all three options.
 
#9
I like your idea for the series/single coil/parallel switches for each pickup plus the master series parallel. I assume this would require two 3-way switches? I already have several 2-way dpdt switches, so for saving a little money's sake I would like to use them, but I am not all that opposed to getting some different ones. With the switches I have, can I make each pickup coil splitting, and then have a master series parallel switch?

I also decided to slim down to one tone knob for both pickups for the sake of not having to drill an input into the side of the body, and I usually have the tone open all or almost all of the way anyway.

I was also thinking of using 500k pots rather that the stock 250k's in order to get a little more brightness out of the pickups, is this a wise idea?

thanks so much again for the help, I'm starting to get a pretty good grasp on this.
 
#10
stevellss said:
I like your idea for the series/single coil/parallel switches for each pickup plus the master series parallel. I assume this would require two 3-way switches? I already have several 2-way dpdt switches, so for saving a little money's sake I would like to use them, but I am not all that opposed to getting some different ones. With the switches I have, can I make each pickup coil splitting, and then have a master series parallel switch?

I also decided to slim down to one tone knob for both pickups for the sake of not having to drill an input into the side of the body, and I usually have the tone open all or almost all of the way anyway.

I was also thinking of using 500k pots rather that the stock 250k's in order to get a little more brightness out of the pickups, is this a wise idea?

thanks so much again for the help, I'm starting to get a pretty good grasp on this.
Click to expand...


Ok, so Series/Single Coil/Parallel switches on each pickup with a master Series/Parallel switch, into a VVT setup?

Which coils do you want to be active in single coil mode?
Inner coils, outer coils, both north coils, or both south coils?

I prefer 500K's to 250K's myself, so i definitely think that's a wise idea, as you would get more output and treble that way, but ultimately that is your preference to choose which pots work best on the bass.
 
#11
Regarding which coils I want active in single coil mode, inner coils was my first instinct.

Could I use the 2 way switches to split each coil and use one master series/parallel switch for a total of 3 switches? due to my budget I think I will avoid the 3-way switches unless you think that is a necessity.

So, if possible I think this is what I am shooting for:

Neck coil split >> Bridge coil split >> Master series/parallel >> Vol neck >> Vol bridge >> Tone
 
#12
stevellss said:
Regarding which coils I want active in single coil mode, inner coils was my first instinct.

Could I use the 2 way switches to split each coil and use one master series/parallel switch for a total of 3 switches? due to my budget I think I will avoid the 3-way switches unless you think that is a necessity.

So, if possible I think this is what I am shooting for:

Neck coil split >> Bridge coil split >> Master series/parallel >> Vol neck >> Vol bridge >> Tone
Click to expand...

Coil splitting for Series/Single Coil/Parallel is done with DPDT On-On-On switches.
A regular DPDT On-On switch will only do Series/Parallel (or Series/Single Coil, or Parallel/Single Coil)

If you want to just use On-On switches rather than the On-On-On, you will lose either series, parallel, or single coil mode, whichever one you choose.
 
#13
ok, I see now. I will indeed go with the 3 way switches for each pickup then.
So it will be:

Series/single coil/parallel (neck) >> series/single coil/parallel(bridge) >> Master Series/Parallel >> Vol(neck) >> Vol(bridge) >> tone

That should do it!
 
#14
Ok, here is your diagram:

3840309786_386f89c680_o.png


Also, there are two types of DPDT On-On-On switches. You need the one shown:
3839520055_b3ec197c4c_o.png
 
#15
thank you very much for the diagram!

I cannot seem to find an on/on/on slide switch anywhere except for the ones for mustang guitars that have 4 prongs. I have found a few toggle switches that are on/on/on but the sites I've visited don't seem to specify which of the two types they are..
 
#17
I just came across this site:
http://www.1728.com/guitar.htm

and to save a few pennies on switches and shipping I think I want to use the DPDT switches for each pickup to go from series/parallel, and then use spst switches to split the coils. This will allow for all the same option with 4 switches rather than 3, and I can just get the switches at radio shack to make my life easier. If I understand correctly, all I need to do with the SPST switch is connect the terminal to the connector that bridges the terminals on the DPDT switch?

Now the only things I am wondering...

Which colors of wire are +\- and for which coils do they correspond to in the T-40 pickups? Can I determine this using a multi-meter?

With the 4 switch arrangement I described above, how do I determine which coils are active in single coil mode? Line6Man, I know your diagram is for the inner coils, but I haven't been able to really figure it out from the diagram how you determine that.


On another note, I am hoping to order the SX bass early next week and have this project completed in a few weeks, I will make sure to post some pictures of the progress.
 
#18
stevellss said:
I just came across this site:
http://www.1728.com/guitar.htm

and to save a few pennies on switches and shipping I think I want to use the DPDT switches for each pickup to go from series/parallel, and then use spst switches to split the coils. This will allow for all the same option with 4 switches rather than 3, and I can just get the switches at radio shack to make my life easier. If I understand correctly, all I need to do with the SPST switch is connect the terminal to the connector that bridges the terminals on the DPDT switch?

Now the only things I am wondering...

Which colors of wire are +\- and for which coils do they correspond to in the T-40 pickups? Can I determine this using a multi-meter?

With the 4 switch arrangement I described above, how do I determine which coils are active in single coil mode? Line6Man, I know your diagram is for the inner coils, but I haven't been able to really figure it out from the diagram how you determine that.


On another note, I am hoping to order the SX bass early next week and have this project completed in a few weeks, I will make sure to post some pictures of the progress.
Click to expand...


Using two switches rather than one just further complicates things. FWIW, you can only go into single coil mode if the Series/Parallel is in series, otherwise the switch will not function.
Just spend a few bucks and buy the proper switch.

Also, you said 4 switches, but wouldn't it be 5 with the master Series/Parallel? Are you going to skip it now and just have the coil splitters?

As far as the color code, I would check in with Peavey and see if they have any info.

The way you would tell is by trial and error.

First off, use your multimeter to identify the pair of pickups.
Once you know which two wires are for one coil and which are for the other coil, you can move on to identify which pair is for the north coil, and which is for the south.

To do this, hook up one pair and tap on the pole pieces gently and see which coil appears to be louder. Sometimes the tap is loud enough to get the other coil to make noise, so you might need to take some time to identify exactly which coil is active when you are tapping the pole pieces.

Once you have identified which pair of wires is for which coil, you can go on to identify the phase.

Hook up the two pairs of wires in parallel and see what it sounds like.
If it sounds ok, then the two wires you are using as hots are the + connections, and the two you are using as grounds are the - connections.
If it sounds thin and nasally, then the coils are out of phase from each other, so flip the pair of wires from one of the coils around.

If you wanted to do outer coils, or both north or south, rather than inner, take a look at the wiring of both coil splitter switches...

The neck pickup has a Series/SC/Parallel switch, and the bridge pickup has a Series/NC/Parallel switch.

You can use either switch configuration, depending on which coils you want active.
Make sure to only change the 4 wires from the pickup, not the connections that output from the switch.
 

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