Why do manufacturers give DCR & what specs should replace it?

[CRU JONES]

No spec gives MEANINGFUL info.

Every customer asking for specs usually like to be BS'ed. They're the ones that THINK they know, and usually a PITA.

So no, no specs for you! (Adapted Seinfeld citation)

the "Spec Nazi" episode! haha

customers actually "liking to be BS'ed"... This is like a revelation!

[km6xz]

The bandwidth for most transducers is about 20khz but some are 500khz. There are new types that have the first amplifier built into the chip that switch synchronized transducers at a high rate to self calibrate and cancel noise so they are easier to design conditioning amps for. Hall Effect transducers are sensitive to current or magnetic fields so are used for measuring both in many diverse applications. For a pickup that I experimented with, I used a bar magnet to create a field cut by the strings and used the transducer to measure the disturbance of the field. The advantage in using a fixed magnet is the string damping is essentially the same as people are used to now with magnetic pickups.

[Lyrebird Steve]

It does tell the customer a little about the Q of the tuned circuit, the slope so it does effect the tone. A gentler slope means lower overtones will he higher in amplitude than if the Q of the resonant circuit was high, where the slope is sharp and the peak higher with lower resistance component of the total inductive reactance of the coil. The DCR also tells the customer what component values in the tone control are needed to have the best energy transfer.
If all else is the same, which is never the case, the DCR would give an indication of harmonic amplitude since it is a major element in the Q of the resonant circuit. No resistance, pure inductive reactance(but real coils also have capacitive reactance ) would result in no harmonics except those falling on the resonant frequency would be present at that output. Very high resistance as a component of reactance would have little frequency discrimination, permitting the string fundamental dominate without much harmonic content. The slope of the resonant filter of the coil's inductive reactance, plus stray and lump capacitance determine the center frequency and the bandwidth of the tuned circuit. The higher the ratio of resistance to reactance, the broader and flatter the filter resonance will be. So lowering resistance enhances higher frequency harmonics, and diminishes lower harmonics and the fundamental. Lowering that ratio lessens the peaking effect of high order harmonics and allows the natural dominance of fundamental and low harmonics. You can see this if you use a spectrum analyzer and magnetic transducer to induce a steady signal into the pickup. Adding resistance will increase the amplitude of lower order harmonics. So if a user really knows about how resonant circuits work, they will be interested in DCR, along with other factors such as inductance. If someone likes your pickup but wants more meat in the mid and lower harmonics, you do not have to rewind the coil, just add a little resistance to the resonant circuit that will increase the fundamental and first couple harmonics. It will lose some of the bite and sting of a highly peaked steep slope resonant circuit. Others want more of it so minimizing DCR without changing the inductive reactive component will provide that.

Some experimental data - I wound two pickups on my CNC winder with almost identical patterns.

Standard A5 Bobbins, 11.3mm tall

S62 - 8,250 turns of 42 Heavy Formvar
T82 - 8,250 turns of 43 Heavy Formvar (yes, HFV)

DCRs were S62 = 6220 , T82 = 8190

Almost Identical shapes to the Frequency response graphs ... but they sound different.

Looking at the Harmonic distribution there are some substantial differences (I'm not sure if this is what's expected or not from the above explanation)

How they sounded to me (given that I installed them into a Fender Bullet Squire Strat from China)
- Both sounded Bright (because of the Guitar)
- The T86 sounded "cleaner" with less of the Strat Quack than the S62
- Both sounded remarkably better than the fridge magnet pickups that came with the china Fender

[Steve Conner]

Seymour Duncan tell you the DCR, inductance and self-resonant frequency of their pickups. I think those three numbers tell you a lot.

Lyrebird Steve, what input signal did you use to get the harmonic distribution?

[rhgwynn]

the "Spec Nazi" episode! haha

customers actually "liking to be BS'ed"... This is like a revelation!

More like a REVOLUTION

-Rob

[Mike Sulzer]

Almost Identical shapes to the Frequency response graphs ... but they sound different.

What is a harmonic analysis? Why is there response at half the fundamental? Why is the fundamental at a frequency above the frequency of a guitar note? Why are the harmonics that you highlighted with a box above the useful frequency response of a guitar speaker?

[Mike Sulzer]

There is NO spec or group of specs that will tell you what a pickup actually sounds like, just like there are no charts or graphs that will tell you what a particular restaurant's steak will taste like. In both cases, there is one way and one way only to find out.

That is not a meaningful comparison. The resonant frequency and damping factor tell you a lot about how it sounds. There is much more to it of course, but why not at least understand how those parameters influence the sound so that you can concentrate on listening for finer details?

[salvarsan]

Think of pickup specs as an FDA-mandated nutrition label. It doesn't tell you how the yogurt tastes but you get information about fat, sugar, and flavorings.

Ditto for pickup specs. This is how you tell an Air Norton from a Super Distortion, and you get a bit more confidence that the pickup builder has notions of quality control.

[Peter Naglitsch]

Answer to OP question "why does manufacturer give out DCR?" Because that is the only measurement that the customer can do relatively easily themselves. You do not revile any "special sauce" ingredients when giving out DCR. It is out there and simple to measure.

Why should we not bother with DCR? Simply because it is irrelevant. I can wind a HB with say AWG 50 and only 2500 turns per coil (just goofing around with numbers here, no real world relevance...) that might end up in the 10K range. Compare it to a traditional AWG 42 HB with 5000 turns per coil (roughly 8-8.5K DCR). Is the 10K HB hotter? No way! Does the DCR say anyting about the pickup and how it is going to sound. Nope! The 10K HBwould have about the half output in mV compared to the 8K traditional version. So much for DCR giving any information at all without also stating the type of wire used.

A bit of trivia: Duncan has diagrams of the "tone" of all their pickups, giving out the bass, mid and treble response of each pickup. I wrote them to ask what frequencies were used for those graphs. The answer was “we do not have any specific frequency for those graphs. It is only a representation of our perception of that pickups tone”. So even when a maker actually tries to use a more specific representation of the tone it might fail utterly.

[kayakerca]

I wound two pickups on my CNC winder with almost identical patterns.

Sounds like you are up and running with your new Haydon dual motion based CNC winder. Still committed to sharing the app with the community?

[Mark Hammer]

We've seen threads here recently where the role of the accompanying wood was discussed as a contributing factor to the resulting spectral content, using the very same pickup. And of course, we all know that the resulting tone will depend on where one situates the pickup along the string length, and how one adjusts the height. No measurements, no matter how detailed or complex, will tell you what you may want to know about how pickup X will sound when butted up against the end of the fingerboard on a 23-fret short scale neck, vs butted up against a long-scale 20-fret neck, even when adjusted to the same height.

In that regard, Bill Lawrence's quote about shoe-size and intelligence is wise and apropos. I can measure DCR at 3k, or at 13k, and be fairly certain about some qualities of the pickup, the way I can note that someone has a child's-size foot (4-5) or an adult-sized foot (10-1/2+), and make some reasonably reliable assumptions about what they can and can't likely reason about. But those indicators will not be particularly precise. And, much like knowing a pickup comes out at a DCR of between 6k and 8k, or that a person's shoe size if 8 or 9-1/2, I can't tell if it's a big kid or a grownup with smaller feet, a poorly-wound coil with thinner wire, or snugly-overwound with thicker wire. So, much like the correspondance between shoe size and intelligence, the correspondance between DCR and pickup properties is non-linear; meaningful at the extremes, but vague and uninformative in the middle (and its a pretty big middle).

The big irony/conundrum/enigma here is that so much CAN be measured and quantitatively conveyed about a coil, except for what it is going to sound like in that position in your guitar, given how you play.

And with that, I'm off to the library to get a book on measurement my kid asked me to get for his high-school philosophy assignment on the paradox of "measurement".

[John_H]

I try to avoid technical discussions, but invite anyone to play my demo guitars.

[ScottA]

Electrical specs (and probably more importantly, parameters extracted from electrical specs) can tell you an enormous amount.

DCR is one of them, but DCR on its own tells you little except in the very limiting case of "all other things being equal".

The all other things being equal approximation may be OK when you're comparing say, a bunch of AlNiCo5 Strat pickups. This is why DCR gets so much mileage, I think, because in some cases that are relevant to the maker and the consumer it can provide some meaningful information.

[ScottA]

Some experimental data - I wound two pickups on my CNC winder with almost identical patterns.

Standard A5 Bobbins, 11.3mm tall

S62 - 8,250 turns of 42 Heavy Formvar
T82 - 8,250 turns of 43 Heavy Formvar (yes, HFV)

DCRs were S62 = 6220 , T82 = 8190

Almost Identical shapes to the Frequency response graphs ... but they sound different.

Looking at the Harmonic distribution there are some substantial differences (I'm not sure if this is what's expected or not from the above explanation)

How they sounded to me (given that I installed them into a Fender Bullet Squire Strat from China)
- Both sounded Bright (because of the Guitar)
- The T86 sounded "cleaner" with less of the Strat Quack than the S62
- Both sounded remarkably better than the fridge magnet pickups that came with the china Fender

You also have to consider how the resistance of the pickup is interacting with the component values in your control harness, that's probably a lot of what you're hearing.

[nickc35]

It takes smarts to wind pickups? And who is this Henry guy everyone talks about?

Speaking of this Henry guy, how does one measure the inductance of a pickup?