Pickup Ratings

[Twitch]

Ok, Ive never understood why companies like Seymour Duncan and GFS, etc. rate their pickups by the resistance of the coil to portray the output a particular pickup has. EMG and DiMarzio on some of their pickups do the proper thing IMO and rate their pickups by the voltage output, which to me makes more sense. When I read that a pickup has an average or peak output voltage of 500mv, I know without a doubt what that equates to in output. Coil resistance means squat to me other than Ive figured out that the higher the resistance, the hotter the output. Its lost on me how the average player can make sense of that, to me coil resistance says nothing about how hard that pickup will hit the input of your amp, output voltage on the other hand, says it all.

So, someone, please explain to me the in betweens of how coil resistance relates to output of the pickup.

[Newc]

Actually, mv tells me nothing about how hard it's going to hit the input of the amp.

I guess since everything else guitar-related is measured in DC resistance and signal impedance (pots, speakers) that it just made sense to them to also rate pickups according to that scale.

IIRC, this question was asked a while back on the SD forum and I think one of the guys from Duncan said that you can make 2 pickups that have the same mv reading but different DC resistance, and that resistance was more accurate than mv.

[Nightbat]

How do you rate a pickup's output when it's dependent on how hard/at what angle/at which length you hit the strings?

Nice that EMG puts a static 'power' value on their pickups, but it isn't static

[Twitch]

Actually, mv tells me nothing about how hard it's going to hit the input of the amp.

...Duncan said that you can make 2 pickups that have the same mv reading but different DC resistance, and that resistance was more accurate than mv.

A tube amp is a voltage amplifying device, it takes the voltage produced by the strings oscillating in a magnetic field, and duplicates at a higher voltage. Lets say you have a amplification factor of 10. You supply the input of the gain stage with 1 volt from the guitar, it gets amplified to 10 volts for output. If the guitar outputs 500 mv, then the same gain stage would yield 5 volts. So if you give me a voltage rating, not static I understand, but an average and I can get an idea of how much gain Im going to have compared to another pickup with a different average voltage output.

As you state, two pickups can have the same average output but different coil resistances, as I figured was possible, then how does the coil impedance give me an idea of how much output the pickup has? If one pickup is wound to 16K and has an average voltage output of 500mv but one wound to 10K has the same output, how does the coil impedance relate to the output of the pickup? I understand it must, or they would not rate them that way, but it seems like it could be misleading as to how much output youll get if two impedance result in the same output, where as with the average output voltage, there is no question which one will result in more preamp gain in the amplifier. Not trying to cause a big debate, if it helps, forget I mentioned output voltage and just explain to me how the coil impedance determines output. Im not claiming its bullshit, Im just not getting the connection.

[Twitch]

Fugg it, just called the old man about it. Says coil impedance is relevant provided you have info about the strength of the magnet as well, so if you have two pickups with same coil impedance and different strength magnets, youll have two pickups with the same coil impedance and different average output voltages. Makes sense now, but that confirms that I need voltage specs to get a definitive idea of how hard the pickup will hit the input stage of my amp, or two sets of specs both stating strong magnets and high impedance for comparison. Off to the web.

[Twitch]

How bout that, the Seymour Duncan page gives me magnet types as well as impedance.

[MakeAJazzNoiseHere]

So does DiMarzio.

The thing is, the coil resistance and magnet strength are really static. But the mv reading depends on how fat the string is, how close it is, etc. as I understand it.

So it seems to make more sense to compare pickups across manufacturers because, well, an Ohm is an Ohm, right? :think:

[Twitch]

So does DiMarzio.

The thing is, the coil resistance and magnet strength are really static. But the mv reading depends on how fat the string is, how close it is, etc. as I understand it.

So it seems to make more sense to compare pickups across manufacturers because, well, an Ohm is an Ohm, right? :think:

I understand the string height, picking dynamics thing etc, like I said, the output voltage would have to be an average, but the impedance of the coil doesnt fit the equation for calculating gain if modding or building an amp. For getting a GENERAL idea of how hot the pickup is, yes ohms and magnet composition can be used, but I cant say 16k ohms X 10= x volts. I guess Ill have to start doing some hands on with my multimeter.

[Twitch]

I forget sometimes, that I am NOT the average musician. Im a musician and a re-engineer and kind of forget that not all guitarists are thinking about the technical stuff or even aware of it. I could see where the ohms and magnet type is the least common denominator, but, honestly, I doubt the average guitarist would take into consideration the magnet type either as being part of the equation. It not a perfect world.

[Hellbat]

The reason EMG doesn't give you the magnet type and the inductance is because the active circuitry prevents the inductance from being read at the output wires. You are likely to get a 1M Ohm reading off an EMG or Duncan Blackout, because what you are reading is the inductance of the (likely unpowered) onboard pre-amplifier and not the coil itself. Thats why the Duncan tone comparison chart has N.A. for all the AHB series pickups. Rating the voltage output is most likely marketing because you have to factor in soooo many variables that it's a useless measure. How high was the string? what gauge? Wrapped or plain? What was it's composition? Did they actually use a tuning fork instead of a string? What frequency is the tuning fork?

It basically just gives EMG the ability to say "This one is for rock and this one is for Norweigan Death Metal" and when the customer says "whats the difference", EMG can say "this one has higher mv so it's better for metal".

[Twitch]

Yes, yes, the general public cant do anything with a voltage rating, and you bring up a good point about the readings youd get from a pickup with a built in preamp. Hadnt considered you cant get a reading from the coil its self, thats why they go with voltage because they have to give you something. I guess Ive got a good excuse to hit the music store with a multimeter to get some readings from various guitars, luckily, theres a couple of stores around here who dont mind me showing up with a multimeter because theres usually a broken amp to tend to as well.

[Hellbat]

Yeah, can you imagine the support nightmare it would be for EMG if they did give the actual coil readings. People would be all "my pickup is defective, it doesn't read 8K ohms, even though it sounds fine."

[MakeAJazzNoiseHere]

I forget sometimes, that I am NOT the average musician. Im a musician and a re-engineer and kind of forget that not all guitarists are thinking about the technical stuff or even aware of it. I could see where the ohms and magnet type is the least common denominator, but, honestly, I doubt the average guitarist would take into consideration the magnet type either as being part of the equation. It not a perfect world.

The problem isn't that you're an engineer and other guitarists aren't, the problem with "the output voltage would have to be an average" is, what is it an average of? Without consistency, the mv reading is completely useless for comparison purposes. You can *maybe* trust a particular company to compare their own pickups using a consistent test method, but to compare two different company's pickups based on "whatever" test method they have independently adopted is TOTALLY useless, however, as I said before, an Ohm is an Ohm.

[javert]

Interesting discussion. I got a bit curious and searched for a model of how pickups function (i.e., an equivalent curcuit) and I found this site, which does a good job of explaining the basics:

http://buildyourguitar.com/resources/lemme/

It's only an accurate model of passive pickups. Strictly speaking, one would need to know the inductance of the coils, the resistance and the capacitance to have a complete characterization of a passive pickup. In relation to the present discussion, it states that the most important quantity is the inductance rather than the resistance, which makes sense to me as the 0 Hz response is of little interest to us.

[Twitch]

Javert, thats an interesting link, MAJNH, youre still missing my point, Im not looking to compare pickups across brands for the purposes of playing, I NEED output voltages to determine an average output voltage to design the front end of an amp. I CANNOT use ohms for this, it doesnt fit the equation. Anyhow, Ive come up with the solution, just need to get on it. Javert, the SD site also shows inductance on their tone chart as well.