Push/pull knobs as pickup on/off selectors -for each half of a MM pickup?

HalfManHalfBass

HalfManHalfBass

Jan 21, 2003
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#1
Hi guys!

I have a question about a possible new bass I want to build.

I want to have a Musicman Stingray type pickup in a passive bass, but with coil splitting (each half of the pickup) using just two push / pull pots.

For example: Volume control (and a push / pull switch) activates the neck half of the pickup,
and the Tone control (and another push / pull switch) activates the bridge half of the pickup.

When both knobs are in the down position, the pickup halves are wired together in parallel -as usual, but whenever either the volume or tone knobs are pulled up: that particular coil is cut.

The only problem I think I might have is that when both volume and tone pots are in the up position there would be no output at all, but more importantly, wouldn't there also be a loud humming, ungrounded noise too like this?

Many thanks,

Peace,

Rob.
 
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#2
First off, I assume you mean coil split. Coil tapping is taking a leader from a different part of the pickup coil, so essentially being able to switch to a lower turn coil.

A more practical method I would say is to wire it up as a switch or two instead of push/pull pots. Some MM basses already come with a single/series/parallel option, which is pretty simple to wire. You may find that there isn't really that much tonal difference between the two coils when singled, so that could be an option instead.

As far as noise goes with your wiring idea, if I'm not mistaken it should just be like kill switches with both off and will just cut all signal. Incomplete circuit = no noise?
 
#3
IWieldTheSpade said:
First off, I assume you mean coil split. Coil tapping is taking a leader from a different part of the pickup coil, so essentially being able to switch to a lower turn coil.

A more practical method I would say is to wire it up as a switch or two instead of push/pull pots. Some MM basses already come with a single/series/parallel option, which is pretty simple to wire. You may find that there isn't really that much tonal difference between the two coils when singled, so that could be an option instead.

As far as noise goes with your wiring idea, if I'm not mistaken it should just be like kill switches with both off and will just cut all signal. Incomplete circuit = no noise?
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Thanks for the reply, IWieldTheSpade.

I have edited my post to read 'coil splitting'. I have been using 'coil tapping' and 'splitting' as interchangeable terminology all my life without knowing there was a difference! -so, many thanks for the info! :)

This pickup is probably going into a P bass along with a split P pickup, so I really don't want to clutter the whole thing up with any more knobs and switches than necessary -especially because I don't like side mounted jacks sockets. Therefore at the most it will have 3 knobs and a jack socket on the front of a standard P style pick guard: 1) Pan (between Split P and MM humbucker, 2) Volume (with pull / push switch to cut out the neck facing coil of the MM humbucker) and 3) Passive tone (again with pull /push switch to cut out the bridge facing coil of the MM humbucker).

I have already fitted a 3 way switch like this on one of my Musicman basses and there is a surprising difference between each of the coils when soloed. I don't like humbuckers wired in series on bass as they always seem too full, loud and muddy, so north single / parallel / south single is a great deal more useful for me.

So you think there won't be any noise when the MM humbucker has both its coils switched off? I was expecting there to be some kind of hum as the live connection won't be earthed...
 
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#4
What you want to do is very simple, you just wire each coil as an individual pickup. The switch shunts the signal to ground to eliminate it from the circuit, so the coil will not make any noise

upload_2016-6-8_8-5-29.png
 
#5
Hopkins said:
What you want to do is very simple, you just wire each coil as an individual pickup. The switch shunts the signal to ground to eliminate it from the circuit, so the coil will not make any noise

View attachment 883468
Click to expand...
Hi Hopkins!

Many thanks for the information! :)

I had a feeling a ground would be necessary somewhere but wasn't sure if I'd have needed a DPDT switch with a ground across pins 1 and 6 (or 2 and 5) or risk shorting everthing out!

1 2
3 5
5 6

In fact as you have indicated, I guess I could even just use a pair of SPDTs now.

Thanks again!

Peace,

Rob.
 
#6
I second a suggestion from earlier. I think you will notice little difference between the tone of one coil vs the other. Series, single, parallel would give you many more tonal options. I have owned a Fender Roscoe Beck Signature like this and I am having a Hammersmith made as we speak that is a P bass at the neck, and a double Jazz at the bridge. Volume and tone. Two small switches. One for neck/both/bridge and one for series/single/parallel for the bridge pickup. Keep the switches small and it won't clutter things up. I pretty much incorporated my favorite things about the Roscoe Beck and a PhD bass into one bass.

I went with a Duncan NYC 5 for the bridge because it will have a Duncan Antiquity II P bass 5 at the neck. I'm really excited to see/hear how it turns out. Should be looking at the end of the month.

Either way, good luck with your project. I love versatile passive basses and it seems that yours will wind up that way no matter which path you choose.
 
#7
HalfManHalfBass said:
Thanks for the reply, IWieldTheSpade.

I have edited my post to read 'coil splitting'. I have been using 'coil tapping' and 'splitting' as interchangeable terminology all my life without knowing there was a difference! -so, many thanks for the info! :)

This pickup is probably going into a P bass along with a split P pickup, so I really don't want to clutter the whole thing up with any more knobs and switches than necessary -especially because I don't like side mounted jacks sockets. Therefore at the most it will have 3 knobs and a jack socket on the front of a standard P style pick guard: 1) Pan (between Split P and MM humbucker, 2) Volume (with pull / push switch to cut out the neck facing coil of the MM humbucker) and 3) Passive tone (again with pull /push switch to cut out the bridge facing coil of the MM humbucker).

I have already fitted a 3 way switch like this on one of my Musicman basses and there is a surprising difference between each of the coils when soloed. I don't like humbuckers wired in series on bass as they always seem too full, loud and muddy, so north single / parallel / south single is a great deal more useful for me.

So you think there won't be any noise when the MM humbucker has both its coils switched off? I was expecting there to be some kind of hum as the live connection won't be earthed...
Click to expand...

Yes a SPST would work just as well.
 
#8
The ground on the switches is not what prevents the hum. Rather, it's the fact that the pickups are connected to volume pots or a preamp, or something that has a finite output impedance, that will keep the bass quiet. As long as you have some reasonable load on the jack, then hum wont be an issue.
 
#9
line6man said:
The ground on the switches is not what prevents the hum. Rather, it's the fact that the pickups are connected to volume pots or a preamp, or something that has a finite output impedance, that will keep the bass quiet. As long as you have some reasonable load on the jack, then hum wont be an issue.
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Many thanks to everyone who has helped, explained and suggested things.

I now feel able to take this project forward and will let you know the results!

I still think 2 single coil options rather than series / parallel / single will be of more use to me, especially when blending in a Split P pickup - it will be like having both a 60s & 70s spaced bridge pickup from a Jazz bass on board.....well in theory anyway!

Thanks again! ;)

Peace,

Rob.
 
#10
HalfManHalfBass said:
Many thanks to everyone who has helped, explained and suggested things.

I now feel able to take this project forward and will let you know the results!

I still think 2 single coil options rather than series / parallel / single will be of more use to me, especially when blending in a Split P pickup - it will be like having both a 60s & 70s spaced bridge pickup from a Jazz bass on board.....well in theory anyway!

Thanks again! ;)

Peace,

Rob.
Click to expand...

You will get 60hz hum when splitting the coil unless you use a 4 coil MM pickup
 
#11
Hopkins said:
You will get 60hz hum when splitting the coil unless you use a 4 coil MM pickup
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Thanks Hopkins,

yes, I have a Nordstrand MM4.4 quad coil on route for this very reason. I have another in an actual Stingray and after much a/b-ing with various Seymour Duncan types, I can truly say they sound great!

Peace,

Rob.
 
#14
I'm not usually in this forum, but here's another option. Check out the wiring diagram in post #4 here: http://www.thegearpage.net/board/index.php?threads/seymour-duncan-p-rail-wiring-diagram-help.603371/

Use basically what they have done on one half of the switches (IOW how they wired one of the pups) and instead of taking the output to the switch (which you don't have) take it straight to the input of the volume pot. I have used this on one of my basses which has a J/MM configuration and it adds parallel mode when both knobs are up. Many good tones!
 
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#15
dabbler said:
I'm not usually in this forum, but here's another option. Check out the wiring diagram in post #4 here: http://www.thegearpage.net/board/index.php?threads/seymour-duncan-p-rail-wiring-diagram-help.603371/

Use basically what they have done on one half of the switches (IOW how they wired one of the pups) and instead of taking the output to the switch (which you don't have) take it straight to the input of the volume pot. I have used this on one of my basses which has a J/MM configuration and it adds parallel mode when both knobs are up. Many good tones!
Click to expand...

That's a cool idea, it would just require two push/pull pots, but it wont kill the pickup like the OP is wanting.
 
#17
dabbler said:
I used it here: NBD (SX content)

Also see posts 281 and 287 here: Show us your 3 pickup basses!
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Hi Dabbler,

Many thanks for the info. but either I'm super stupid or it's too early here, because I can't understand it! :)

Are you saying that with a pair of push / pull DPDT switches I can have all 4 options from a single humbucker?

i.e. both switches in the down position= series
both switches in the up positions= parallel
one switch down the other up = north single coil
the opposite of above = south single coil

If that is possible I would be very interested but would probably reverse the connections so that the Musicman humbucker is usually in its 'traditional' parallel mode with both pots / switches in their down positions. I'm just having difficulty getting my head around the schematic because the quad coil pickup I am using should only have 5 wires: 2 for each noiseless single coil and an earth.

Peace,

Rob.
 
#18
HalfManHalfBass said:
Hi Dabbler,

Many thanks for the info. but either I'm super stupid or it's too early here, because I can't understand it! :)

Are you saying that with a pair of push / pull DPDT switches I can have all 4 options from a single humbucker?

i.e. both switches in the down position= series
both switches in the up positions= parallel
one switch down the other up = north single coil
the opposite of above = south single coil

If that is possible I would be very interested but would probably reverse the connections so that the Musicman humbucker is usually in its 'traditional' parallel mode with both pots / switches in their down positions. I'm just having difficulty getting my head around the schematic because the quad coil pickup I am using should only have 5 wires: 2 for each noiseless single coil and an earth.

Peace,

Rob.
Click to expand...

1. Yes that's exactly what I'm saying.

2. 5 wires is fine. The ground goes to ground and the diagram shows you what to do with the other 4 (again, in the diagram, each pup is only wired to one side of each switch).

3. Making the parallel mode the both down position should be doable, you'll just basically wire them upside down.
 
#19
dabbler said:
1. Yes that's exactly what I'm saying.

2. 5 wires is fine. The ground goes to ground and the diagram shows you what to do with the other 4 (again, in the diagram, each pup is only wired to one side of each switch).

3. Making the parallel mode the both down position should be doable, you'll just basically wire them upside down.
Click to expand...
Hi Dabbler,

I just wanted to say thank you for providing me with this information! This morning I made a mock-up of the circuit with a pair of switches and think that this is going to rock!

WP_20160611_10_30_27_Pro_zpsc3psfulu.jpg


With just a volume and tone control on my bass -but fitted to push / pull switches I'll have 4 different sounds and without any drilling for extra mini switches! I love your circuit because with the knobs down in their normal positions I'll have a standard, parallel Stingray sound, but then I can pull either up to cut out either coil and when both are up: get series as opposed to my original plan which would have just plunged me into silence!

This is what the internet was designed for: sharing knowledge and helping out your fellow (bass)man! Thanks to Hopkins and everyone else who has contributed -I'm forever grateful and reserve the right to bore you all senseless when I finally get this project finished with photos!

Have a great weekend to all,

Peace,

Rob.
 
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