Extech readings

[EFK]

Can someone who knows what they are doing (not me in other words!) answer this for me? If you took a reading w/ an extech lcr meter (series, 120Hz,) and the pickup was 8.12 K and 4.84 H, then you make a simple change (not coil windings) and it reads 8.33K and 5.625 H, how would you *in general* expect the sound to be affected? Or not at all? Im just learning here so maybe it's a silly question!

[defaced]

I'm far from someone who know's what they're doing, but my guess is that the frequency response would change. I don't know enough about pickups to know which way it would change, but that'd be my guess.

[salvarsan]

If you took a reading w/ an extech lcr meter (series, 120Hz,) and the pickup was 8.12 K and 4.84 H, then you make a simple change (not coil windings) and it reads 8.33K and 5.625 H, how would you *in general* expect the sound to be affected?

The new sound will have less treble. More Henries == less treble.

Sounds like you added more steel to the magnetic circuit.

The AC resistance reported by the ExTech may indicate more eddy currents
but no one can say until we know more about the pickup design.

What is the DC resistance reported by an ordinary meter?

-drh

[Magnut]

Typically a higher inductance will create a darker sound with less highs and a lower inductance will sound brighter.

[Possum]

....

Well you're reading at 120Hz you're down in the bass range so it means your bass clarity got more muddy. INductance shouldn't be the only thing you look at, yes generally the higher the inductance the darker the tone is, but also when you put a baseplate on a tele bridge or a P90 or a humbucker the inductance will DROP, but the AC resistance will go up...

[Mike Sulzer]

Well you're reading at 120Hz you're down in the bass range so it means your bass clarity got more muddy.

Increasing the inductance does not affect the bass significantly because the impedance of the inductor at low frequencies is small compared to other impedances in the circuit.

INductance shouldn't be the only thing you look at, yes generally the higher the inductance the darker the tone is, but also when you put a baseplate on a tele bridge or a P90 or a humbucker the inductance will DROP, but the AC resistance will go up...

The losses in the pickup do indeed go up from adding a plate to a tele bridge, but I see no evidence that the inductance changes significantly. That is, the resonant frequency stays the same.
I think the Extech is letting you down.

[EFK]

Well this sure got too complicated to me very quickly! I was just curious what would happen if you put a 1/8" thick piece of steel on the bottom of a bright HB. Sounded like crap! Weak - I'd guess it was pulling too much magnetic field away from the strings. Just playing around.

[EFK]

Maybe I ought to try adding an extra magnet instead...

[Possum]

....

It depends on what kind of pickup we're talking about here. Humbuckers have problems in the bass area, single coils much less. If you change something in a humbucker that loads the pickup down more you will see a significant muddying of the bass end of things, but it may read as an inductance decrease depending on what you did, add metal, or add winds or change magnet type. Single coils have way less problems in the bass frequencies so your readings at 120HZ are much less seperated than what you get from a humbucker.

[belwar]

Typically a higher inductance will create a darker sound with less highs and a lower inductance will sound brighter.

so if you have a lower inductance is there also a coresponding drop in low end? I would imagine that a lower inductance on most pickups is desireable

[David Schwab]

I wouldn't go so far as to say it's a drop in low end as much as an extended high end. Often what sounds "warm" to people is less high end instead of more low end. Low inductance pickups wont have the hump in the mids either.

But higher inductance pickups do have a fuller tone.

[Possum]

........

When making a chance in loading though when inductance goes lower it gets muddier not clearer. Thats the bitch of this stuff, and thats why you need to watch AC resistance. Sometimes you have to look at all 3 readings to make any sense of making a change in a pickup design, the inductance drops, the AC resistance goes up at the same time, what does Q do as well? Its not cut and dried...

[Mike Sulzer]

When making a chance in loading though when inductance goes lower it gets muddier not clearer.

No. The pickup is unloaded at low frequencies because the impedance of the inductance is low. You must be hearing some other effect and misinterpreting what it is the result of. Have you looked carefully at the stated errors of the Extech when the Q is low?

[Possum]

...

its not an error and its easy to do, take a strat pickup for instance and put a steel bar across the pole, sticking it to it, the inductance drops, the AC resistance goes UP....

[bbsailor]

No. The pickup is unloaded at low frequencies because the impedance of the inductance is low. You must be hearing some other effect and misinterpreting what it is the result of. Have you looked carefully at the stated errors of the Extech when the Q is low?

Mike,

Could you summarize the kind of things one can learn about a pickup coil from using the full features of the Extech LCR meter at both the 1K Hz and 120 Hz test frequencies.

The Extech measures AC resistance (AC-R), L, Q and D. I found that when I multiply the AC-R times the Q, I get a value very close to the coil's XL. Do you find this to be useful?

If the Q of a coil is below 1, how would you interpet that?

Joseph Rogowski