Picking out the control configuration

So I've ordered an EX-4 bass kit with some customization and I have no idea what I’m doing when it comes to picking out my own control configuration. I’ll give some specifics about the project and my own thoughts, but I would love to hear input from people with more technical know-how and first hand experience with this!

The body will have the standard 3 pre-drilled holes for the pots in a straight line and a relatively narrow cavity. I definitely do not want to drill a 4th hole, but I am open to making the cavity larger, if needed.

I am having them route the body for a single musicman pickup and I’ll be dropping in a Nordstrand mm4.4 quad coil and rocking it passive. This pickup can get neck, bridge, parallel and series functionality. I’m pretty sure that is all the potential combos (someone please correct me if there are more!), so that takes up one hole for a 4 position rotary switch right off the bat.

For the other two holes these are the options I’ve come up with so far:

1) Tone and Volume

2) Stacked v/v and stacked tone/master volume

3) Stacked v/t and stacked v/t

4) Stacked t/t and volume

I would greatly appreciate any and all advice on configurations and even specific pots, capacitors, values and so on!

My experience comes mostly from re-wiring a G&L bass. I have mine wired so that I can select series, parallel, single-coil-bridge and single-coil-neck. Series and parallel are good settings, although I don't use the parallel much. It's similar to the single coil but loses a little of the sparkle. The difference between the two single-coils is so subtle that I can't really tell them apart. If it were me, I'd just do one of them. You could do that with a three way rotary.

Alternatively you could add a tone cap to the fourth position on your switch. Lots of ways to do this, but since you are setting up for SC modes... On older G&L basses there is a .1u cap between the coils in the series setting. This gives the pickup a boomy sound and is referred to by folks who have them as the OMG cap. I have a switch on mine to take the cap in and out, which you might wire to the 4th position on the rotary. This would give you two series positions. If you like a boomy sound it's cool to have, but I mostly run without it. It's a tad too boomy, and unbalances the coils so it's not quite humbucking with the cap in. That said, it would give you four really distinct sounds.

I don't see much reason for two tones or two volumes on a single pickup bass...unless you want to do something like the PTB wiring...also something on G&Ls...

You might take a look at the wiring diagrams done by Ken Baker at "Basses by Leo"

https://www.bassesbyleo.com/

https://www.bassesbyleo.com/passive_l_series.html

Of course for that classic MM sound, the pickups are wired in parallel.

I was a bit stumped at first to work out how they had four coils but two rows of pole-pieces, then realised that each row was a 2+2 pole split coil, like a Precision Bass pickup. So even the single coil selections are hum-cancelling.

I'd agree with Fender3x that the sound between the two single coil positions is going to be very similar. I had an OLP MM style copy with each coil having its own volume control, so you cold have one or the other coil or both together in varying amounts. The two pure single coil sounds were pretty indistinguishable.

If it were me, I'd probably just chose the neck coil as the single coil (assuming the pickup is going in the midway single-pickup MM position), and have that along with series and parallel as your options. Just that bit easier to track which setting you've got, especially with a rotary switch and makes for a nice easy wiring arangement.

I'd go for the rotary switch, volume and tone. If you had a tone per coil, they'd both be selected in series and parallel mode, which would double the capacitance value.

My preference would be for a 500k audio taper volume pot and a 250k tone pot. Cap value depends on how dull you want the bass to be able to sound with the tone turned right down. I'd suggest either a 0.033uF or 0.022uF cap, probably a 0.022uF (slightly brighter) cap, as you need to keep some note definition. With audio taper and a 250k pot, the tone control starts to operate far sooner and is more controllable over the pot's travel. Both a linear taper and 500k (compared to 250k) selections cause the majority of the tone roll off to occur much closer to the bottom end of the tone pot operation, and having 500k and a liner taper pushes that active section down even further. But there are no right or wrongs here, it is down to how you like your tone controls to behave.

Whilst you can add loads of switching and various capacitor options, you'll probably find that most of them give sounds you'd only use very occasionally unless maybe you are playing the bass as a lead instrument or are into more experimental music. For standard group use, it's very easy to make the sound too thin to carry a bass line, or too muddy to cut through the mix.

Simon raises an interesting point. Where will the pup be?

FWIW, my G&L ASAT has two pups. Neck coils would line up more or less with where a modern J-bass's pups are located. I have the same switching options for both pups. I really can't tell the difference between the two single coil settings on the bridge pickup either.

I had forgotten that you have four coils. On a normal humbucker the only real use I have had for parallel is for when what I really want is single coil, but I need humbucking. Since you have four, you could consider doing...

XX Series XX Parallel X "single coil" and X P-bass
XX XX X X

BTW I would also recommend that you put the "single coil" and the "P-bass" coils in series. Judging by p-bass pups and by my old Dimarzio J side-by-side humbuckers, they both sound really thin in parallel.

Though split, each half of the pickup is internally wired as one coil, so you can't do a staggered P-bass arrangement. It's got 4-conductor wiring, and you'd need 8-conductor (or 2 x 4 conductor wiring as some Kent Armstrong pickups have) to do the staggered configuration.

Not a bass but a production 6 stringer, Shergold Masquarader Custom.

A pair of split coil humbuckers.

Split coil options on both pups are, S/C, HB out of phase, HB

Combination options are N, Parallel, B

So effectively a massive range of options at the flick of a switch.

I just knew you needed more configs to stress over :D

This is just one dual coil pickup, though both coils are hum cancelling. Best treated as a 4-wire humbucker.

Thanks for the great suggestions!

The pickup should be more or less in the traditional sweet spot; it's a custom job with a medium scale neck... we'll see what I get from the factory! If it's close enough, I'll just leave it, if it's way off I may need to do some routing and filling.

I had wondered about the single coils being too close to really be distinctive. It would certainly simplify things considerably to leave one of the coils out.

Simon is correct, this pickup just has the 4 wires to work with, so I don't think doing the P-bass split is an option, unfortunately.

I need to do some investigation into adding a cap between the pickups in series, that sounds very interesting. I have a feeling this is gonna send me down a rabbit hole of all sorts of weird mods haha. Gotta fill the time waiting for the bass to ship somehow!

Quote:

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Originally Posted by starsloth

I need to do some investigation into adding a cap between the pickups in series, that sounds very interesting. I have a feeling this is gonna send me down a rabbit hole of all sorts of weird mods haha. Gotta fill the time waiting for the bass to ship somehow!

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Bummer that I won't do the p-bass configuration. There are a lot of mods involving caps down that rabbit hole if you have an extra stop on your rotary switch. Another simple one would be adding another cap to the tone control so that you can channel Robbie Shakespeare ;-)

I thought long and hard about different configurations for my EX-4. I ultimately decided to just go with V/V/T because I'm more used to this setup from mostly playing a thunderbird for the last 10 years, also have 2 jazz basses with same configuration.

I'm quite interested to see what you settle on.

best of luck with your build

Quote:

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Originally Posted by fender3x

My experience comes mostly from re-wiring a G&L bass. I have mine wired so that I can select series, parallel, single-coil-bridge and single-coil-neck. Series and parallel are good settings, although I don't use the parallel much. It's similar to the single coil but loses a little of the sparkle. The difference between the two single-coils is so subtle that I can't really tell them apart. If it were me, I'd just do one of them. You could do that with a three way rotary.

Alternatively you could add a tone cap to the fourth position on your switch. Lots of ways to do this, but since you are setting up for SC modes... On older G&L basses there is a .1u cap between the coils in the series setting. This gives the pickup a boomy sound and is referred to by folks who have them as the OMG cap. I have a switch on mine to take the cap in and out, which you might wire to the 4th position on the rotary. This would give you two series positions. If you like a boomy sound it's cool to have, but I mostly run without it. It's a tad too boomy, and unbalances the coils so it's not quite humbucking with the cap in. That said, it would give you four really distinct sounds.

I don't see much reason for two tones or two volumes on a single pickup bass...unless you want to do something like the PTB wiring...also something on G&Ls...

You might take a look at the wiring diagrams done by Ken Baker at "Basses by Leo"

https://www.bassesbyleo.com/

https://www.bassesbyleo.com/passive_l_series.html

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I did a PTB on my LTD "les paul jr" shaped guitar, 2 pickups on it but the PTB is a nice subtle way to clean up the mud (or leave it there) when using distortion.