The LMP Z-Series™ Manifesto

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Some changes are coming from Lawing Musical Products, the makers of Zexcoil® pickups.

We started this company about 7 years ago, after a preceding 2 or 3 years of development, to market our unique line of one-coil-per-string, hum-canceling pickups. We founded our company on a few underlying principles:

  1. A commitment to providing great products for the best price we could,

  2. A commitment to domestic supply and manufacturing, and

  3. A commitment to establishing a viable, independent and growing company that would help sustain us, as well as employ others, at a living wage.

We’ve learned a lot in these 10 years or so, both about the musical instrument business and about how to build great pickups. What we’re about to do now is borne out of both of those learnings.

We’ve come to realize that our relatively complicated pickup design is too expensive to produce, to the point that we can’t achieve all of our goals under the current paradigm. We needed to make some significant changes to how we produce these pickups to really become viable. What we’ve done is redesign the Zexcoil pickup to make it as inexpensive as we can. We’ve done this by eliminating redundant parts, commonizing parts where we could and streamlining the process required to build a pickup. As a result of this effort we have a less expensive pickup that retains the Core Zexcoil design, and because it’s inherently more efficient, sounds at least as good and in many ways better than our Legacy models. The only significant practical difference between our new Z-Series™ and Legacy™ Zexcoils is that the Z Series pickups are potted in their covers. This makes the Z-Series covers non-removable, while the Legacy pickups have interchangeable covers.

After much thought, we’ve also decided to continue with our direct internet business model. This allows us to cut out all of the middle men and give our customers the best possible price on these pickups. While we know that our superior performance can and always has commanded a premium, that’s not what this is about. It’s not about making as much money as possible. It’s about making enough money to be viable and sharing the benefits of our efficiencies with the end user as much as we possibly can.

So here’s what’s happening. Our model line and pricing structure will change significantly. We will be introducing the new Z Series pickups with the full range of analogs to our current Legacy models, and at the same time expanding our output range into the lower end of the scale, with new models that are closer to vintage pickup specifications than we have ever been.

Our Z-Core™ 5 family of pickups will be priced at $79.99. That’s 20% lower than any pickup we’ve offered to the general public before. The Z-Core product line represents pickups designed by us and assembled at our US partner factory, the same factory where our coils have always been wound. The initial Z-Core offerings will include our most popular voicings, with analogs to the Legacy SV5 and SV5O, and some new lower wind AlNiCo 5 voiced pickups that are closer to vintage single coil specs than anything we’ve ever made. These new lower wind sets are also designed for the same 250 kΩ controls that most conventional single coil equipped guitars use.

We will have a range of Custom Shop options based on the new Z-Series platform (including new Tele bridge pickups), with voicings analogous to our Legacy models, priced from $89.99 – 105.99. These Custom Shop models will include our 2, Fat 5, Convertible, Juicy and Throaty voicings. Custom Shop models will be built by us, and our handful of local builders, by hand. As demand warrants, we plan to migrate as many Z Series models as we can from the Custom Shop to the lower priced Z-Core line. Design and performance of Z-Series Custom Shop and Z-Core pickups are identical, the only difference being the economies of scale at which they are manufactured.

We will be offering a range of sets featuring 3 Z-Core 5s starting at only $225, and multiple options for mixed Z-Core/Custom Shop sets below $250. We also have Custom Shop Tele bridge/Z Core (Strat) neck sets starting at just $170.

We will continue to offer our Legacy product line through the Custom Shop, although the prices will be adjusted to reflect the realities of the costs involved in producing these pickups. We’ve designed the Z Series product line to cover all of the same bases as our Legacy pickups and there are Z Series analogs of just about every Legacy model. All of the new pickups incorporate the design concepts and philosophy of our Legacy products, in fact we believe that they represent the most advanced evolution of our approach to pickup design. The Z Series pickups are just a more efficient and streamlined version of the same great one-coil-per-string hum cancelling idea we’ve always had.

We will be raising the prices of our Legacy models to $129.00 with the full release of the Z-Core and Custom Shop Z-Series lines. We are targeting August 1, 2017 for the full release, and we will take orders for the Legacy models at the current prices up to that date.

 

Electrical Parameters and Pickup Performance, Part I - Resistance

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In the course of developing the Zexcoil hum canceling format, I was faced with some insurmountable engineering problems with the materials that are conventionally used in Strat-style single coil pickups. As I have been explaining, the pole piece is primarily responsible for defining the timbre of a passive electric guitar pickup, and in the case of single coils it is the electromagnetic properties of AlNiCo alloys (and most specifically AlNiCo 5) that define the classic Strat tone. The problem was, AlNiCo alloys don’t work very well in the Zexcoil format because they can’t effectively close the magnetic dead spot between the D and G strings (where the magnetic polarity flips so we can get hum canceling). So I was forced to develop an understanding of what it was exactly that caused AlNiCo alloys to “sound” like they do and how I could get the same response from different materials, materials capable of closing the magnetic seam.

We think we were successful in solving the problem, but we’ll let you judge that by your impressions of our pickups. What we also got though, was a physical model for the electro-magnetic response of pole piece materials that basically allows us to create a map of tonal characteristics. We use this map in the design of all of our pickups. Since this is a basic model, the general responses are not limited to Zexcoil pickups, and pickup performance in general can be interpreted in the same context.

But we’ve struggled with how to make that information accessible to players to the extent that they can use it to guide their own pickup choices. We’re going to try some new things coupled with the roll out of our Z-Core™ and Z-Series™ models this summer. One of the things we’re going to do is provide a lot of the electrical specs for the various models.

In order for that information to be useful, it’s necessary to place the raw numbers in a tonal context. Resistance, Inductance, Resonant Frequency, Quality Factor, that’s all great: but what does it SOUND like? We’re going to attempt to answer that question, or at least provide some good guidance that might allow players to interpret the electrical specs more easily. We’ll start here by discussing the electrical parameters that we consider critical and describing what they are and what they mean in a terms of pickup performance.

First, the most ubiquitous electrical specification in use today, and by most accounts the most meaningless, Resistance. Electrical resistance is exactly what it sounds like; it’s the tendency of a material to resist electric current. Resistance is measured in Ohms, the symbol for which is “Ω”. Sometimes you’ll see a “k” in front of the“Ω”, and this means multiply by 1,000. So for example, 250 k Ω is the same as 250,000 Ω, it’s just shorthand.  In almost all electric guitar pickups, resistance is a function of only two things; 1) the total length of wire that encompasses the pickup’s coils and 2) the gauge (or more accurately: thickness) of that wire. You can think of resistance like the width and length of a pipe that you are trying to pump water through. The narrower and longer the pipe, the harder it is to push to get the water through. So then, the thicker the wire (or the lower the gauge number), the lower the electrical resistance. The longer the wire, the higher the electrical resistance.

Most Strat style single coil pickups use an identical design and dimensions, the same 42 awg copper wire and similar AlNiCo 5 pole pieces. In this limiting case of “all other things being equal”, resistance actually is a pretty good descriptor of pickup performance. That’s one reason that it has become so widely used. But, change one thing and it starts to get a lot less meaningful. Change the wire gauge, and the resistance for the same length of wire changes. Change the pole piece and the output will change, even at the same resistance (we’ll talk about some of those effects in the next blog post on Inductance). Even change the material used for the wire, say from copper to silver as in the Seymour Duncan Zephyr pickup, and resistance will change at the same length of wire since resistivity (resistance per unit volume) is a property of the material and silver is a better conductor, in that it has inherently lower resistivity than copper.

So, resistance is not a great number as an absolute measure of pickup response. In the Zexcoil format, we pretty much use the fattest wire we can for any given winding level, and we may use 2 or 3 different wire gauges in a single pickup to get them tuned where they need to be given our unconventional magnetics. Resistance also represents a loss of efficiency, and in keeping with our over-arching philosophy of maximizing efficiency, we basically try to keep the resistance as low as possible for any given design.

Pickup Resistance and Pot Values

One place where resistance does become important is in how the pickup interacts with the controls. The simplest way to think about a potentiometer (“pot”) in a guitar is as a gate. A typical guitar control is just a variable resistor in a circular format. The knob turns a wiper that is contacting a semi-circular resistive strip, with one end of the strip connected to ground. When on “10”, the full resistance of the pot blocks the path to ground.  When the pot is set to “0” that block is removed, and pretty much all of the signal goes to ground and we get no volume. When the pot is on “10”, most of the signal is retained, but some of the higher frequencies can manage to sneak through the pot and get lost to ground. The higher the value of the pot, relative to the pickup, the less high end is lost. Go back to the water analogy. Think about the volume pot/pickup system as a garden hose with a pin hole in it. The water coming out of the nozzle at the end of the hose is like the signal going out to the amp. With a small pin hole in the hose, almost all of the water in the hose still comes out the nozzle, but just a little bit of spray will escape through the pin hole. That spray is like the high end being lost through the volume pot. A 250 k pot versus a 500 k pot is like a bigger hole in the hose so more spray is lost. A volume pot on zero is like a hole in the hose big enough so that all of the water comes out the hole and none makes it to the nozzle. Strat style single coils, with resistances on the order of 5,000 Ohms or so, generally use 250 kΩ pots. Hum buckers, which typically have higher resistance than single coils – approaching 10,000 Ω, are usually better balanced with 500 kΩ pots. A good rule of thumb is that the pot value should be 25-50x the value of the pickup.

We refer to this scenario of attaching a resistance along with the pickup as “loading”. Tone pots (at “10” anyway, when you start dialing down the resistance of the tone pot, the tone capacitor comes in to play and things get a lot more complicated) represent a similar “load” on the pickup as a volume pot. In fact, when you have both a 250 kΩ volume and tone pot connected the effective resistance to ground is only 125 kΩ, so more signal (highs go first remember) can bleed over the lower barrier. A “No Load” tone pot is one in which there is a physical break in the resistive strip just below “10” on the dial. When the wiper is in the “10” position then, the pot is disconnected from ground and the load is removed. With a no load tone pot on “10” the only path to ground is through the volume pot. This has the audible effect of maintaining more of the high end “air”, and the tone will darken up noticeably when the tone pot is engaged just below “10”, especially through a clean amp. Go back again to the water analogy. A no load pot is like putting a bandage over the pin hole when the pot is on “10”, so the hole in the hose is plugged up and the spray is not allowed to escape. Just below “10”, as the resistive strip is engaged, it’s like the bandage has been removed and the spray through the pin hole is allowed out. We like to use no load pots on the neck and bridge positions, and we especially like the way they open up the “in between” positions. For most typical control layouts, the bridge pickup can benefit from tone pot loading, so we don’t use them much there. One exception would be the Convertible for Bridge where we like to use the no load tone as a “load toggle” between the two modes; unloaded for the higher resistance series mode to let all of the power come through and loaded down a bit more to attenuate the highs on the lower resistance parallel mode.

The New Z-Series™ Pickups from Zexcoil®

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You may have heard some rumblings about our new Z-Series™ pickups.

Well, the rumblings are true, we have been developing a new Zexcoil® platform for the past year or so. As you can imagine, producing a six coil, hum canceling pickup is expensive. Every part in a Zexcoil pickup is custom made to our specs, and we don’t share any common parts with any other pickup. You can’t go to a guitar parts supply house and set yourself up to make Zexcoils, like most conventional pickup winders can. We came to the realization that, in order to remain viable, we needed to come up with an improved version of our unique design that would retain all the good parts of our current line while being less expensive to produce. We did that, and more.

The new Z-Series pickups share much with our Legacy Series™ (the new name for the original line). Both incorporate our patented, hum canceling Zexcoil one-coil-per-string platform and both use our patented T3 Tone Tuning Technology™, our catchy name for the underlying materials engineering that shapes the tone of our pickups. The Z-Series is basically just a re-engineered version of the original Zexcoil, where we’ve communalized parts, eliminated unnecessary parts and removed multiple laborious production steps. In effect it’s a refined, improved and more efficient imagining of a Zexcoil in many respects.

Figures 1 and 2 illustrate exploded views of the Z- and Legacy Series pickups. These designs share the same bobbin and coil. Similar pole piece materials are used in both designs (with some differences that I will explain below). The Z-Series uses six magnets, a dedicated magnet for each bobbin/coil, while the Legacy Series uses only two, with each magnet serving a group of 3 coils. The Z-Series does not utilize the pole piece caps that most Legacy Series models do. Many of our models incorporate a laminated pole piece, and the pole piece caps on these models serve to provide a nice finished look, while also adding a significant mass of magnetically permeable metal in the flux path, close to the string. Since Z-Series models are potted in the covers, pole piece caps are not required. Potting in the cover also serves to eliminate a large part of the labor involved in producing a Zexcoil.

There are a few other things that make the Z-Series different, and in some sense “better” – at least more efficient from an electrical standpoint. One thing that isn’t obvious from Figures 1 & 2 is that we have rebalanced the coil and pole piece allocations in each slot. As a result, we get more of the output via pole piece mass (more magnetically permeable material in the core of the coil concentrates more of the magnetic flux in the core and results in higher output) so we can reduce the number of windings in the coils. Fewer windings yield lower resistance. So in tech speak, we get more Henries with fewer Ohms. We’ve also folded this improvement back into the Legacy line, because we can!

Elimination of the pole piece caps is effectively the elimination of an “eddy current speed bump” in the middle of the flux path. While the Legacy Series Zexcoils incorporate caps, these designs were also optimized around the caps being in place so they sound great the way they are. But the fact is, the caps aren’t required to generate a signal and when the caps are removed the pickup becomes more efficient. For instance, all other things being equal, a pickup without pole piece caps will generally have a higher Q value (see below) than a pickup with caps.

The incorporation of individual magnets for each coil also results in an efficiency gain. While we originally did it just to simplify the design (the Z-Series magnets are interchangeable in terms of North/South magnetic orientation – so only one part is required – while the Legacy Series magnets are “handed” – requiring two parts), what we didn’t appreciate until we built one, tested and played it, is that decoupling the coils magnetically is a fundamentally more efficient way to do it. The same way that removal of the pole piece caps improves Q, magnetic decoupling of the coils results in a similar “improvement”.

Add all of these benefits up and it enables us to use a less exotic, and also more magnetically permeable, pole piece material in the Z-Series. For instance, the pole piece configuration that sounds like slightly lower Q AlNiCo 3 in the Legacy Series design sounds like higher Q AlNiCo 5 in the Z-Series format. And, in relation to the efficiency gains from increasing pole piece mass discussed earlier, a more magnetically permeable pole piece allows us to get higher output at even lower resistance. So much so that the “vintage” output Z-Series models have similar or even lower resistance than their conventional counterparts. A significant implication of this efficiency gain is that these vintage output models are totally compatible with, in fact optimized for, 250 kΩ potentiometers. You can just drop them into your existing controls!

We will be officially introducing Zexcoil Z-Series pickups very soon.

Appendix – A brief discussion of “Q”

The parameter “Q”, or the quality factor, is used in many branches of physics. In a general sense, Q is a measure of the energy stored in a system compared to the energy lost by the system in a given cycle. For an oscillator, a high Q means the oscillator will ring for a long time. For a mechanical system, like a pendulum, a high Q means the pendulum will swing for a long time. Systems with higher Q can generally be thought of as more efficient since they make better use of the energy that is input to them. For an inductor, like a guitar pickup, Q is a function of frequency. The most convenient definition of Q for a guitar pickup is taken at the resonant frequency. The Figure below shows how Q at resonance is calculated from a plot of impedance versus frequency for a guitar pickup. So for a guitar pickup, a taller, narrower resonant peak is indicative of higher Q.