Ibanez HFS pickups - I'm curious

[Mark Hammer]

I was flipping through the current Ibanez catalog and came across their JTK line of guitars. The JTK guitars use a rather unique pickup called the "HFS". From the side view, it appears to be a sort of P-90/Lace-like pickup, but with a cancelling dummy coil wound around the sensing coil. Judging from the catalog, the entire dual-concentric-coil package comes in around the P-90 footprint size.

It's an intriguing idea. Does anyone here have any experience with concentric cancelling coils?

[Mike Sulzer]

That is an interesting idea. The first thing to notice is that it shares one of the disadvantages of the old type of stacked humbucker: the canceling coil picks up some of the signal and cancels it as well. The reason that it does not cancel it all is:
1. the flux from the vibrating string that passes through the main coil has to return to the string. Some of it passes through or inside the canceling coil, reducing the signal in that coil;

2. The canceling coil has larger area than the main coil, and so it needs fewer turns in order to pickup the hum with equal strength, and so it also picks up less signal.

So the inductance of the canceling coil is less than that of the main coil, but I think it is still significant, and so one should expect some loss of highs.

I suppose you could think of this as a dummy coil that is smaller than one would like, and mounted in a non-optimum location.

[frankfalbo]

I suppose you could think of this as a dummy coil that is smaller than one would like, and mounted in a non-optimum location.

Bingo

[David Schwab]

There was at least one patent for a coaxial humbucker similar to this from 1983. I think their might be more.

4372186 (see attached screen grab). Looks just like the Ibanez design.

I had this idea many years ago, but never tried it. I suppose you can try using large diameter wire for the dummy coil, like the Ilitch system, but you still run into the phase cancelation problem Mike mentioned.

Bill Lawrence had two; 3711619, and 5376754, but in those the outer coils was for tonal adjustment, and not for hum cancelation.

[Mark Hammer]

I think it is fair to note that the ad copy for the guitar in question conveys the impression that it aims for a 60's oddball guitar vibe. In other words, it is not trying to sound like SRV or Billy Gibbons, so all conventional wisdom about the tonal impact of such coils is tossed out. I'm not suggesting that is somehow "less". Rather, the normal thinking of "If I do this, I'm gonna screw up X" is not hemming in design, and whatever the tonal outcome is is treated as musically valid and idiosyncratic rather than "wrong".

That patent diagram David shows sure enough looks like it, though.

[David Schwab]

You hit the nail on the head Mark.

I've had a few guitars with stacked pickups, like the old Duncan stacks. They have to over wind them to make up for the reduced low end, but they sound just like single coils. I have some lawrence L-250s and a dual rail Tele pickup in another guitar. They sound great too. Maybe not exactly like a particular Strat pickup, but, really, who cares?

I think too much emphasis is placed on getting exactly the same tone as SRV or Billy Gibbons or whom ever, and they sure weren't thinking about using a particular pickup to sound like someone else! I love their playing and tone, but I don't want to sound like them.

I miss the 70's where people were happy to try new things. Too many people lack originality these days! Music has become a uniform that you rent.

If you can't get an interesting tone from any guitar with any pickup, there's a problem! And it ain't the guitar.

[the great waldo]

You hit the nail on the head Mark.

I've had a few guitars with stacked pickups, like the old Duncan stacks. They have to over wind them to make up for the reduced low end, but they sound just like single coils. I have some lawrence L-250s and a dual rail Tele pickup in another guitar. They sound great too. Maybe not exactly like a particular Strat pickup, but, really, who cares?

I think too much emphasis is placed on getting exactly the same tone as SRV or Billy Gibbons or whom ever, and they sure weren't thinking about using a particular pickup to sound like someone else! I love their playing and tone, but I don't want to sound like them.

I miss the 70's where people were happy to try new things. Too many people lack originality these days! Music has become a uniform that you rent.

If you can't get an interesting tone from any guitar with any pickup, there's a problem! And it ain't the guitar.

HOW TRUE

Cheers

ANDREW

[automan]

Music has become a uniform that you rent.

Forgive me, but I am going to steal that and use it in real life

[Mark Hammer]

Music has become a uniform that you rent.

If you can't get an interesting tone from any guitar with any pickup, there's a problem! And it ain't the guitar.

I will overlook the "nail" pun and say that the boldfaced line is quotable. That's a good'un. Copyright it.

[David Schwab]

I can't take full credit!

I stole it from this XTC song:

Travels in Nihilon

You've learnt no lessons
all that time so cheaply spent
there's no youth culture
only masks they let you rent

Travels, travels in Nihilon
we've seen, no Jesus come and gone

Fashion, their vampire
drapes itself across your back
as you fall from style
it waits rebirth on its rack

Building your whimsy
hypnotising you to need
dance goes full circle
one step ahead of your greed

You've learnt no lessons
all those years to get it right
flashes of promise
burn out faster than strobe light

Sums up the idea that if you only follow fashion trends, you will be left with nothing but wasted time when the new trend replaces the old.

I get bored real fast with music and other things. I'm always looking for something I have never heard before.

[Possum]

....

Its an old idea and that patent has been posted here going back five years or more. Yes I tried it a long time ago but the results were very muddy. I suspect they are using some kind of shielding material in between the two coils. Also note that the pickup in the patent probably never saw the production line, I've never seen a pickup like that and note that it says it produces a hi-fi type tone. I imagine it may have been larger than a regular humbucker as well. Just goes to show there really aren't any new ideas, just different iterations of stuff thats been done before....

I would think they are probably using two different guages of wire too, my attempt was with just 42 and the dummy coil part wasn't enough turns to kill the hum.....would be interesting to get hold of one of those pickups and take it apart.....

[Possum]

...

I wonder if the "metallic frame for magnetic field" is actually magnetic and acting as two outside poles, now THAT would be unique. Its probably something like Mu metal though, I bet. Cool idea....

[David Schwab]

I wonder if the "metallic frame for magnetic field" is actually magnetic and acting as two outside poles, now THAT would be unique. Its probably something like Mu metal though, I bet. Cool idea....

Yeah, it is. A lot of the stacked pickups are like that.

Here's a Dimarzio. The shield is touching the bottom of the magnets and leading the field back up to the strings.

The bottom coil only has metal slugs and is would with less turns of heavier wire.

[Mike Sulzer]

I wonder if the "metallic frame for magnetic field" is actually magnetic and acting as two outside poles, now THAT would be unique. Its probably something like Mu metal though, I bet. Cool idea....

If it is something like Mu metal, it does tend to act as a partial return path for the the changing flux from strings passing through the core of the inner coil and back to the string, thus reducing the cancellation in the outer coil. It is an incomplete shield, and I would not expect much more than a 6 db effect based on a few experiments I have done.

[Possum]

...

I'm not quite understanding why heavier guage wire with fewer turns on the dummy coil would be total cancelling, maybe its not? Personally I'm not a fan of fake single coils and don't really even like matched winds on anything, it sounds sterile and too many good frequencies are cancelled. Good for high distortion though, eh?