Is my Seth Lover mis-wired or the coil upside down?

[JEH]

I have a Seth Lover SH55n 4-wire pickup - had it from new. If I wire it as instructed - connect and isolate the RED+WHITE wires, connect GREEN to the shield and earth, and take the signal from the BLACK wire, the sound is incredibly thin and lacking any bass - clearly the two side of the pickup out are of phase.

I am testing this without any other wiring - just hooking the jack socket up to the pickup.

The pole pieces seem to be correct, one is north the other south. So as far as I can work out, either the wiring colour coding is wrong, or one coil is upside down. If the colours are wrong I could just hook it up with colours swapped around but a continuity check shows the coils are BLACK~WHITE and RED~GREEN with the the neck side and screws on the RED+GREEN side which seems to be correct.

Testing the guitar with different connections, I get the creamiest sound with BLACK+GREEN joined to earth and RED+WHITE joined as hot output.

I've been Googling all day and found a few reports of apparently mis-wired SD pickups. In production, can I presume the two coils are normally wound exactly the same way but one of them is turned over to reverse its phase - so the opposite N~S poles bring them back into phase? If one coil was mounted the wrong way, reversing the red and green wires would fix the phase problem but will the result be exactly the same as turning over the coil?

...yes, I'd then have two in-phase signals but now one of the coils would be grounded at the start and the other grounded at the finish (I think) - I can't get my head around it TBH! Would that make an audible difference because maybe the hot end of the coil is closer to the bobbin (2k ohms closer as well as physically closer) - with a change of capacitance?

Listening to the guitar with one coil wired up, I could hear a difference if the coil start was ground or hot.

Thanks for any advice ~ John​

 

[ehdwuld]

Digital multimeter

Red and green wire

Hold a screw driver of large steel something on top of the screw coil
Pull it straight up and away from the PU quickly

Does the value on the screen jump up or dip down

Your coil reading should either get larger or smaller

Now thw white and black pair

Same thing

One should get larger
One should get lower

Post and let us know

 

[jeremy]

the physical orientation of the coil doesnt matter, what matters is how they are wired. each coil should be around 4k dc resistance. it should be black/white and red/green for the two coils, but i would check all the possibilities to see if there is something is mis-wired.

 

[freefrog]

Testing the guitar with different connections, I get the creamiest sound with BLACK+GREEN joined to earth and RED+WHITE joined as hot output.

That's parallel wiring. if you want the coils in series like in a normal humbucker and if effectively the coils are initially out of phase, the correct wiring should be white + green connected to each other and the other colors going respectively to hot and ground.

Yes, such things happen, BTW. I had once to rewire an old SH1 with the same problem, albeit the PU had a 2 conductors cable. I don't know if it was a mistake from factory or if the first owner was the culprit but the coils were certainly OOP.

 

[JEH]

Thanks for everyone's answers!
ehdwuld yes my meter goes plus or minus but of course it depends which way round the leads are connected. So pulling a spanner away from the pickup I get a +ve voltage with White or Red connected to the common on my meter. (Red+Green seems to be on the South Coil with the screws)

jeremy - I actually converted my bridge single wire pickup today. Looking at its insides, it would be fairly impossible to accidentally have the coils upside down or the wrong way round, (maybe if the North coil pole pieces were pushed in from the wrong side?) so I think it must have a pair of wires switched - maybe my reply to @EDWULD is enough to work out which pair?

freefrog TBH I'm not sure I like the sound of series coils - I need to play around a bit more but it seems too thick and muddy for me. Rob Mods on YouTube thinks says it makes a difference which end of the coil is used as the hot signal, suggesting the start of the coil is near the pole pieces, creating a capacitance that can dull the tone. I suppose if the hot end is outside it will be a couple of thousand ohms away. ¯\_(ツ)_/¯

 

[freefrog]

freefrog TBH I'm not sure I like the sound of series coils - I need to play around a bit more but it seems too thick and muddy for me. Rob Mods on YouTube thinks says it makes a difference which end of the coil is used as the hot signal, suggesting the start of the coil is near the pole pieces, creating a capacitance that can dull the tone. I suppose if the hot end is outside it will be a couple of thousand ohms away. ¯\_(ツ)_/¯

Man, you're free to prefer parallel wiring and I'm glad to know that I'm not the only one to care about parasitic capacitance...

That said, the slight difference of brightness due to swapped start/finish wires wouldn't compete with the clarity of parallel wiring, which is due to lowered inductance (divided by four in parallel comparatively to series).

 

[ehdwuld]

Red green should be one coil

Black white should be the other

with that said

Think of it black + white - red - green +

Now do the readings go in opposite directions when either connected positive + to the hot lead of the DMM
and the negative - connected to the common lead of the DMM

as long as the two readings are opposite
meaning one ascending
And one descending
they have opposite polarity

if you have any other wire colors as pairs for the coils
if you have a yellow or blue wire

if the red and black are one coil

any other combination at all

something has been doctored on or that's not an SD pickup

 

[freefrog]

BTW and to put things in perspective: I've worked several times on wiring mistakes with 4 or 5 -cond. cables coming necessarily from the factories since the guitars had been bought brand new... Happened for instance with an Expensive Telecaster American Deluxe and with a cheaper Nashville style Tele hosting TWO miswired pickups - a mid stack whose noise cancelling coil had been shorted and... a bridge Duncan stack that its factory wiring was making noisier than a real single coil albeit it respected the Duncan color code.

 

[freefrog]

Also and to put in perspective what Rob Mod said on YT...

Below is the electrically induced response of a Duncan P.A.F. clone, wired in series, with standard vs reverse wiring (IOW: with start and finish wires swapped for both coils).

Yes, the lower capacitance due to reverse wiring gives an extended high range.

But it happens beyond 12khz while in this case, reversing the wiring gives LESS brightness to the South coil from 6 to 14khz...

What does it show? That parasitic capacitance definitively matters, especially with 4-cond. wiring. But also that generalizing about that is impossible: what makes a pickup or coil brighter in one case might make the next one darker. A few picoFarad's of difference suffice for that.

FWIW.

 

[JEH]

@EHDWLD There's absolutely no doubt my pickup is mis-wired since with red+white joined and isolated, green grounded and black as hot there's such a weak thin bright signal. It was bought from a reputable guitar shop - not off Amazon so I'm sure it's a genuine Seth Lover SH55b. But it was bought July 2020 at the height of COVID so maybe PPE got in the way during manufacture?

freefrog Wow, not sure what 'induced response' is but it clearly shows a difference in making the start or finish of the coil hot. But since I can barely hear 8kHz perhaps 'induced response' is not quite the same as output frequencies? No doubt there are a thousand other factors that affect the sound - like input impedance etc - so I'm convinced now that the way to get the best out of any pickup is to try various wiring combinations and ignore the colours!

 

[freefrog]

Wow, not sure what 'induced response' is but it clearly shows a difference in making the start or finish of the coil hot. But since I can barely hear 8kHz perhaps 'induced response' is not quite the same as output frequencies?

Below is a primer to read. Fig. 11 shows how the response of any magnetic PU can be electrically induced.

http://buildyourguitar.com/resources/lemme/

 

[Mincer]

It isn't very common that a pickup leaves the factory mis-wired, but this forum proves that it does happen once in awhile. I actually had my Seth Lover neck pickup rw/rp from the factory so I could do some particular switching with it.

 

[ehdwuld]

For the third time

Please do the tests and post the results

Oh its purchased new
it sounds weird

None of which answers the questions
could have a short some where
it could be any number of things

Please do the tests
Post the results
And we may be able to help correct it
Or at least find the best option

But without test results
We haven't a fkn clue
what's in your fkn hands


Data please post data not your emotions

Edit

Ok I give up

I'm out

 

[JEH]

For the third time

Please do the tests and post the results

Oh its purchased new
it sounds weird

None of which answers the questions
could have a short some where
it could be any number of things

Please do the tests
Post the results
And we may be able to help correct it
Or at least find the best option

But without test results
We haven't a fkn clue
what's in your fkn hands


Data please post data not your emotions

Edit

Ok I give up

I'm out

Sorry ehdwuld I thought I gave you all the info you asked for in message #5 not sure what else I can add. Maybe coil resistances - individually they are about 3.5k Ohms and isolated from each other, so not likely to be a short anywhere. I've been spending hours trying different combinations of wiring and have settled on one that works fine for me. For the bridge pickup I'll have a toggle switch for parallel coils OR single coil out of phase - that seems to sound best. For anyone who'd like to know what's going on inside the Seth Lover pick I've uploaded an image - it shows the USB cable ready to connect.

 

[xxxplorer]

Not to hijack, but I thought I was crazy until I read Treefrog talk about parasitic capacitance. I always noticed my 2 conductor/shielded pickups just felt better. So I always order them that way.