Meter readings on pickup install?

[vjm]

I just put in a set of SD Antiq Texas Hot strat PU. The DC resistance readings on the SD website are as follows: neck & middle 6.3....bridge 9.7
Using a three foot patch guitar cable I get the following readings with my multi meter: 6.05 neck, 6.24 middle & 9.4 bridge.
They sound a bit weaker than I expected. Should the pickups always read what the website says or should you expect some variance? thanks!

 

[bagman67]

Short answer:  Who cares what the resistance reading is?


Longer answer:  The DC resistance number is shorthand for rated output, or something, I'm not sure what - but often the number does not bear a one-to-one relationship to actual loudness.  Use your ears, grasshopper.  Have you used these pickups elsewhere, or is this the first guitar you've installed them in?  If you've never heard them before*, maybe you just don't like them. But as a practical matter, try adjusting your pickup height to see if you get better results when they are closer to the strings.




*  If you've only heard them in a Youtube demo, you haven't heard them.  All the lossy compression and digital artifacting that occurs when a video goes to youtube guarantee that whatever you heard, it wasn't a perfect reproduction of your pickup being played into an amp.

 

[Cagey]

Should the pickups always read what the website says or should you expect some variance? thanks!

You should expect some variance. Also, you should ignore it.

Basically, all coil resistance tells you is how many winds are on the bobbins, and that's not as accurate as you might expect. Your meter will have tolerances, the wire will have tolerances, etc. If you'd like to use those numbers anyway, then you have to consider the magnet material and its gauss rating, as well as the gauge of the wire (which will change the resistance). Then, there's the pole pieces, their size, orientation, permeability, etc. There are other details as well, but you'll end up with an inductance value in Henries, which is more indicative of the thing's ability to behave as a transformer, although even that is not predictable because the primaries are your strings, which are unpredictable.

Bagman's advice is good: adjust your pickup height. If that doesn't make you happy, change pickups. Also, don't use price as a guideline. Overall, there really aren't any bad pickups out there any more.

 

[vjm]

Thank you for the replies.

 

[vjm]

After thinking about it and setting aside the meter readings.  I think that the sound that I am not completely satisfied with may be the wiring. I used some silver wiring that I had laying around. I remember a few years back I rewired a guitar with the same silver wiring and ended up re-wiring that guitar with normal threaded wire. With the silver wiring it gave the guitar a nasal, pinging type of tone in the mid-range. After using normal wire the guitar was back to sounding the way I liked it. Does anyone here have any expierience with the silver wire? Just curious....Hopefully by reading these forums we can prevent someone from making the same mistakes. I am going to rewire the guitar this weekend and report back.

 

[TroubledTreble]

All of the above comments are spot on. Resistance is futile..... for equating how a pickup will sound.

Consider this, two pickups can have the same exact resistance reading but because they were wound with different gauge wire they will sound very different. A pickup wound with 42 @ 6k ohms will have an average output while a pickup wound with 44 @ 6k ohms will not have as much output. The smaller wire having more resistance will take less winds to make 6k. So a pickups output can also be tied to how many winds are on the bobbin. In the end the the ohm reading from the manufacture is best used to compare to, insuring you don't have a broken pickup.

One more factor for having a different reading than stated by manufacture is temperature. The temperature of the pickup will change the resistance reading. Higher temp = higher resistance. I think most baseline readings are at ~72-75deg F.

 

[Cagey]

Does anyone here have any expierience with the silver wire?

While silver is a better conductor than copper, the difference is small and only noticeable over long runs. The lengths of the wires involved in the control cavity of a guitar are much too short for you to even be able to measure a difference with a very sensitive meter, let alone hear any difference between solid/stranded or copper/silver wire. So, rewiring to change conductor type will be an exercise in futility.

However, it is possible there's an error in the wiring causing your low output, so at least some review is in order.

 

[drewfx]

Using a three foot patch guitar cable I get the following readings with my multi meter: 6.05 neck, 6.24 middle & 9.4 bridge.

In addition to what everyone else has said, if you have other things (like a volume control) in the circuit along with the PU, it will reduce the measured resistance.

 

[Jumble Jumble]

^ what he said. If you're measuring while wired into the guitar then the pots will be having an effect on the resistance.

I just did some rough back-of-an-envelope calculations and I reckon that with 250K pots wired in you'd be looking at:

Neck & mid: 6.3k becomes 6k
Bridge: 9.7k becomes 9k

Depending on the wiring of the guitar, of course.

Basically your numbers look fine. They wouldn't have sent them out of the factory with the wrong number of turns on the pickup. The reason you check DCR of a pickup is to check the coil isn't broken or shorted, both of which will result in vastly different numbers to the given spec.

 

[Strat Avenger]

DC resistance is not an indication of a pickup's output.

A perfect example is the Dimarzio HS-3 (A.K.A. "YJM"). It has a DCR of around 23k ohms, yet has a weak output.

 

[Cagey]

DC resistance is not an indication of a pickup's output.

Right. If it were, it would be as simple as adding a 25MΩ resistor in series with a pickup to increase it's output a bajillion times. Blow any ol' Marshall to smithereens instantaneously. Maybe even power up the outbuilding where the drummer lives.

 

[line6man]

Like others have said, all sorts of factors contribute to what the DCR of a pickup will be. It just so happens that if you put more wire on a pickup, its resistance will go up. Do not mistake this for any sort of relationship between resistance and output. There are really only three reasons that a pickups DCR should mean ANYTHING to you. If you are building pickups; if you are trying to gauge the similarity of pickup impedances, as they will relate to how well they will play together; or if you are trying to authenticate a claim that a pickup you have bought is what the seller says it is.

 

[Cagey]

This will make some people sick, but...

Back 100 years ago, we used to get old Gibson PAF pickups for next to nothing when aftermarket replacements first became available. Guys were swapping those things out right and left to get "hotter" units that would overdrive their amps because distortion/overdrive pedals and master volume amps were pretty thin on the ground, and they didn't all sound that great.

So, we'd take these pickups, separate the series coil connection and measure the DC resistance of each. Then, we'd unwind one or overwind the other to "balance" them. At the time, we were convinced it was an improvement.

Point is, the only thing we used DC resistance for was to measure (very) roughly how many winds there were on the pickup.

The tragedy was, those things are highly prized these days, and we were essentially "destroying" them. Although, many of them would have just been tossed otherwise. If we only knew...

 

[Laika]

This will make some people sick, but...

Back 100 years ago, we used to get old Gibson PAF pickups for next to nothing when aftermarket replacements first became available. Guys were swapping those things out right and left to get "hotter" units that would overdrive their amps because distortion/overdrive pedals and master volume amps were pretty thin on the ground, and they didn't all sound that great.

So, we'd take these pickups, separate the series coil connection and measure the DC resistance of each. Then, we'd unwind one or overwind the other to "balance" them. At the time, we were convinced it was an improvement.

Point is, the only thing we used DC resistance for was to measure (very) roughly how many winds there were on the pickup.

The tragedy was, those things are highly prized these days, and we were essentially "destroying" them. Although, many of them would have just been tossed otherwise. If we only knew...

+1

Also, lots of people swapped those vintage pickups from their 70's era strats for EMG's when they became the "in" thing.  Not the brightest move in-hindsight.



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