XR16 pickup wiring

[Alan Murphy]

I have just bought a new XR16 12 string pickup and am about to fit it - which has the following wires

WHITE - Hot
RED - Center
BLACK - Ground

As I understand it,

The pickup has two magnets per string one with N upward and the other S upwards

There is typically a clockwise winding (A) around all the upward Norths and an anticlockwise winding (B) around all the upward Souths

The two windings (A and B) are wired in series giving for me a DC resistance of 22 kOhm and with RED being the middle point then WHITE to RED or RED to BLACK is 11 kOhms (as expected)

The Humbucking idea is that the metal string causes an induced voltage in coil A of the N upwards and an in-phase induced voltage in the coil B of the S upward because of the two inversions (magnetic & winding direction) and as the windings are in series the output is doubled

However EMI external noise does not use the magnetics and induces a voltage in coil A and a 180 degrees out of phase voltage in coil B (due to winding direction) and as the windings A and B are in series the noise is cancelled,

So for Humbucking you would use the Hot (WHITE) and Ground (BLACK) wires with the Center (RED) wire disconnected

Now to the interesting bit .. (Single Coil)

When you use the WHITE and RED wires as the output you are just using coil A and I assume it is a good idea to short out coil B by also connecting the BLACK wire to the RED wire otherwise coil B will behave as an unwanted RF aerial !!

Similarily you could instead choose to use coil B by using the RED and BLACK wires as the output and this time short out coil A by also connecting the WHITE wire to the RED wire otherwise coil A will behave as an unwanted RF aerial !!

These two options would seem identical HOWEVER each of the magnet rows are at a different distance from the changer so i would expect the row closest to the changer would give a sharper sound

It is pretty easy to wire to switches to give the three options - Humbucker - Single coil Bright - Single coil Mellow

Is my theory correct and has anyone tried the three options ?

There may be a fourth single coil option - Use the center RED as a ground and have the WHITE and BLACK as two independant outputs (one sharp and one mellow) and externally switch them or blend them electronically. (or the second independant coil output to a tuner)

I assume a widemount pickup has more spacing between the two lines of magnets so the sharp / mellow effect may be even more apparent

[David Higginbotham]

I've used the XR-16 in two Carter steels years back but I haven't tried any of the options you've explained. They were wired only as humbuckers.

But I'm not certain if there's enough difference in proximity of the rows to the changer to have a discernible tonal difference. If so, then we're hearing two distinct tones from a singular humbucker pickup when both rows/blades are active. I've never read where anyone has made a comparison or chosen to run one closer or further from the changer to achieve a desired tone for the scenario you described. By that I mean they chose the particular row/blade because it was brighter or more mellow.

As for wide vs narrow mount and there being a difference in distance between the two rows of magnets...there isn't. The pickups are the same and only the mounting tabs are different to accommodate narrow mount, such as Shobud or earlier Mullen, and wide mount for MSA or Emmons. Even on the original chrome 705 pickups...the same pickup could be used in either simply by changing the mounting plate.

I'd be interested as well hearing from someone who's taken the time to explore the options you've detailed and if there is enough of a difference to justify the extra work.

Dave

[Alan Murphy]

Hi David,

Thanks for the reply

I have just measured the distance between the two lines of poles as 16mm, nearly 3/4 inch

I will be fitting the pickup tomorrow and will try each coil in single coil mode and see if I can hear any difference between them.

If there is a noticable difference, then in humbucker mode it is a mix of the two tones

I think two lines of magnets in this design of humbucker have to be kept far enough apart so the magnetic fields don't interfere much with each other, maybe that is the reason many think the single coil is a more pure sound!

I will update tomorrow what I find, thanks Alan..

[Fred]

The easiest way to do this is to wire the white as hot and the black as ground and use a switch to short the red to either white or black. This is pretty common in the guitar world. You will hear very little difference between the individual coils. They're just too close together. I suggest listening to both and picking one, then switch between full and one single coil option.

[Bob Carlucci]

alan.. Can't tell you much about your pickup specifically, but can tell you this much about humbucking pickups in general.. since your pickup is 3 wire, I am not sure you can use it full humbucker and then isolate either coil.. Thats usually done with 4 wires, but I am not sure how your pickup is configured. What I can say with 100% certainty is this- IF you can configure your pickup as a full humbucker and can isolate both coils, there is a very noticeable difference in tone,, Works the same way on 6 string humbuckers.. The single coil closer to the bridge will be brighter and less powerful than the humbucker, and the coil further from the bridge, will have a bit glassier, more "out of phase" sound, that will not be quite as bright as the rearmost single coil.. I have been doing this for decades, and when other pedal steel players have heard me play in years past, they often asked about how I got these sounds.. It is a VERY worthwhile setup, that very very few players use these days for some inexplicable reason.. I use a DPDT "on-on on" switch with position 1 being the single coil closest to the bridge- position 3 being single coil furthest, and full humbucker in the middle, which I rarely use. The way my ears perceive my sound is like this.. The rearmost coil sounds like a twangy early 60's steel tone, kid of like the sound of an old Fender 400. Further single coil a bit rounder, sweeter, not as tangy, more like a Sho Bud might sound... Full humbucker is just thicker, louder, more powerful, and not as bright of course... If you can do it, I would. If not, with a 3 wire, I imagine you can isolate 1 coil.. If thats the case, personally, I would put that coil farther from the bridge, as to my ears, its the sweetest most usable tone on the guitar i have now, or on any steel I have had in the past... For years GeorgeL had a pickup called the 10-5 which was brilliant.. Did a lot of the things I wrote about, with a 5 way switch!.. 5 distinctly different sounds.. They discontinued that great pickup many years ago for reasons i will never understand. Let us know how you make out.... bob