Testing pickups with multimeter?

[Steve_Karl]

I just bought some pickups from eBay and need to test them but don't have a guitar to mount them in.

Can some one tell me how to test them with a multimeter?

Please note: I'm pretty clueless when it comes to meters. I just got my first one a few months ago and have
only used it to test cables.

Thank you!

 

[Dan025]

set it to measure resistance, it may need you to select the range and have ranges that start with the number 2 for whatever reason, it just seems to be a popular setup. if so select the range that goes to 20,000 or 20k ohm. measure. the ideal number depends on the pickup but is typical not less than 5k ohm and not greater than maybe 16k ohm but some lace sensors go higher than 20k i think.
if it is a humbucker or other wise has more than 2 conductors you can see which pairs of wires go to each coil. and see if every thing is grounded. if it is a strat syle p/up you can check for a short against the pole pieces which can happen if they ever got hot or if the poles are rusting.

 

[Steve_Karl]

Very good instructions. Copied to my notes.
Thank you!

Steve

 

[Steve_Karl]

Dan - Hello Again !

Please verify my interpretation here?    ( I have no experience with meters. )
The meter is set to X1K OHM.

This is an Alembic (meant for an active system) Strat pickup and I should call this approx. 3.75K ohms?

and one other ... a Gibson BurstBucker Pro that I should read as about 4.2K ohms?

And will a higher value (generally) mean more output?

Thanks !

 

[line6man]

And will a higher value (generally) mean more output?

DC resistance means absolutely nothing.
It's simply the measure of the coil's resistance to direct current.
Thicker gauges of wire will have a lower resistance, thinner gauges will have a higher resistance.
If you wire two coils in series, their DC resistances will add together. Parallel will descrease by (R1*R2)/(R1+R2).

 

[Steve_Karl]

So you're saying the measured value has no effect what so ever on the potential output of the pickup,
or is this a thread hijack for the sake of a physics lesson?  :help:

 

[line6man]

So you're saying the measured value has no effect what so ever on the potential output of the pickup,
or is this a thread hijack for the sake of a physics lesson?  :help:

The output of the pickup is determined more by the number of winds around the coil.
More wire equals more output, and at the same time, more wire also equals a higher DC resistance, so if you compare two otherwise equal pickups, the one with more turns of wire will have more output and a higher DC resistance.

OTOH, if you compare pickups with different wires gauges, coil configurations, etc.., the DC resistance will mean nothing in terms of output level.

 

[drewfx]

If everything about the construction of 2 PU's is more or less identical (type of magnet, wire gauge/type, etc.), comparing the measured resistance can be meaningful. But if the PU's are significantly different, you can't really draw any solid conclusions from those kinds of measurements, as the other factors in the PU's construction can have a greater influence on the PU's sound/output/etc.

 

[Steve_Karl]

If everything about the construction of 2 PU's is more or less identical (type of magnet, wire gauge/type, etc.), comparing the measured resistance can be meaningful. But if the PU's are significantly different, you can't really draw any solid conclusions from those kinds of measurements, as the other factors in the PU's construction can have a greater influence on the PU's sound/output/etc.

Yes! That is logical.
That answers it for me, because what I am comparing are 4 Alembic strat pickups. 3 from a matched set and 1 extra that an Alembic tech sent me about 10 yrs ago that is "slightly hotter" ( his words ) than the normal set.
My mission being to discover which one will be most effective in which position.
Measurements are ( approx.) 4.35k ... 4.4K and 4.5K and the hotter one is about 4.75K.

So now I at leaset have a place to start when installing.

Thanks!

 

[Dan025]

i'm not familiar with those, one thing to watch out for is how you hold the leads, depending on if your hands are wet and how hydrated you are your body can influence the readings.

i would guess you got a set of good readings, there is some variation but not all over the map, i'd guess the higher reading pup's are meant for the bridge position. but i'm sure you already knew that.

you say that it is meant for an active system, will it be used with a preamp? will they just be wired up as single coils? just curious.

 

[Steve_Karl]

Hey Dan,

Good thought about watching ones skin condition when doing this. My hand's were clean and dry and finger tips are calloused.
I need 2 more alligator clips to eliminate the potential for human contamination  

Yes. 3 of them will be used in my korina padouk/bloodwood strat project that is almost finished and will be used with the original intended Alembic pre amp.
It's an old STR/AE-3 system with 1 volume active treble and active bass.
I have the same system in my old stand by warmoth hard tail mahogany maple/ebony strat.
I don't use amps anymore and haven't for about 20 yrs. so that's why I initially went for this system. It's very sensitive and responsive to playing with fingers only, and going direct into the console or just a mic pre.
Fingers: www.sightsea.com/music/singles/always_solo.mp3
Pick: www.sightsea.com/music/singles/could_intro.mp3

Higher in the bridge ... yes ... and that is why I was originally talking with the Alembic tech and why he sent me a stronger pup back in the late 80's.
I remember swapping out the bridge pup on my mahogany but I think I might have went back to what was originally in there for some reason ...
possibly the way the weaker one worked when having middle and bridge on together was nicer to my ears.

 

[line6man]

one thing to watch out for is how you hold the leads, depending on if your hands are wet and how hydrated you are your body can influence the readings.

Yep.

Also, the resistance can change based on the temperature as well.

 

[BigBeard]

Honestly I don't use a multi meter to test to see if a pickup works.  I use my amp and a guitar cable.  I hold one lead to the tip and one to the sleeve and tap the pole pieces with something like a little screwdriver.  I will also hold a pickup up to another guitar and strum the strings to see if I am getting any output.  I know this isn't the most intelligent way to test a pickup, but it definately will let you know if the PU works!!  I just test to see if it works or not.  I can't tell anything else by my test, like output or anything like that.....  Just if the PU functions....

I have been testing PU's this way for years.  I used this technique way before I ever bought a multimeter!!

:cool01:

 

[Alfang]

I'm going to disagree with a few people here,  DC resistance of a pickup is a very good indicator of pickup output.

Why? because MOST pups are wound with 42 Ga. wire or 43 Ga. most pups magnets are pretty close in their gauss strenght.

The bottom line, most of us do not own an inductance meter, ( i do) having measured lots of pickups DC readings and inductance (henries)

and compared the two, they are on very similar predictive curves. And despite the many diferrent pup makers out there, with just a very few exceptions, all pups are made the same way.

So like I said, with a few exceptions, you can make a good guess as to the pickups performance based on DC readings.

TT's roadhouse pups do not follow the typical DC rules because he has a few tricks that he does, but seymour duncan, frahlin, lollar, and all the famous pups are all built the same.

 

[Dan025]

95% of the time as alfang said dc resistance is a good indicator of inductance which is an indicator of output, some people are sticklers for correctness, and this time it wasn't me.

resistance may not be a measure of performance but if it is the only information you have it can be useful.

it is good when comparing a strat p/up to a strat p/up, a tele to a tele and a humbucker to a humbucker. it is the best reading we have with conventional equipment as long as there are not too many other variables.

fact is though if you have radically different designs even knowing all the measurements, inductance, resistance, Q, gauss, you still cannot measure the performance without plugging it in.

even with the normal vintage construction there is variation in pole piece length possibly material, magnet dimensions and location and in the case of a humbucker, the number of magnets.

with bar magnets the permeability(sp?) of the pole piece material is a factor in inductance which is a factor in the resonant peak and output. changing the pole piece screws on a p-90 or humbucker can make a huge difference in tone.

if you have a method to accurately view the shape of the magnetic field and had much experience experimenting with pole length and magnet placement and coil shape then you may be able to make an educated guess. remember that we are not all bill lawrence and cant contemplate all these things all the time. and that a vast majority of p/ups are based on gibson and fender designs, variations are limited to a few things that are easily noted and measured.

 

[-CB-]

i'm not familiar with those, one thing to watch out for is how you hold the leads, depending on if your hands are wet and how hydrated you are your body can influence the readings.

Yah, and not yah.  Generally, it is bad practice to allow your fingers to touch the exposed leads or probe tips ANY time you take ANY reading.  Generally, it will throw off resistance readings if both hands touch the leads or tips. 

Practically, on a resistance reading under 100k ohms, its of no great matter... insignificant.

Practically, if you had your fingers in an amp, you're butt would be, as Foghorn Leghorn would say, "fricasseed".

 

[-CB-]

I'm going to disagree with a few people here,  DC resistance of a pickup is a very good indicator of pickup output.

Only an indicator... you still cant compare apples and oranges via the RESISTANCE of the wire, except when all else is equal.

Magnet strength, pole length (and in general the magnetic circuit), coil footprint, where the pickup will sound good in relation to the strings, all that jazz etc etc

Yes, pickups have a magnetic circuit, and how the strings and coil interact with it is very important.  Yes coil dimensions count.  Yes, some pickups sound like crap when too close or far from strings, and others are totally opposite. 

In practical terms, one might conclude that the higher DC resistance used more wire, or smaller wire, both tending to give higher output and tending to give less high end, but as a basis for comparison on different pickups of dis-similar manufacture.... its about like looking out your window and sayin' its gonna rain, just because you see a cloud.