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Koss and PG outputs

EpiLP1985

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Aug 11, 2017
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Not static at all. Temperature changes the value to a noticeable degree.

True, but unless we assume major swings in temperature from reference (20 C/68 F), it won't be as drastic as you think.

Relatively speaking, it's the most static of all the other variables!

Generally speaking you'll see a 0.35 k ohm increase per 10 C. That kind of resistance increase isn't going to drastically change the voltage output for a specific current. With that said, even as an electrical engineer (I am not an electronics guy but rather utility distribution and protection), I am not well versed enough to know what a 30-100 mV increase in signal will do to the input of an amplifier, although you'll get some attenuation going through the passive control circuit.
 
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Tarcisioo

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Oct 5, 2014
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385
So, if I just don't want to geek out and I just need to know it a pickup is hot, what shall be done?

We don't really need lab tests, nor the exact experimentally controlled value for output, just to know if a pickup is a strong or a weak one

DC output is something anyone can do, and is pretty consistent in a lot of cases. As a matter of fact, it never failed me in telling a strong pickup from a weak one
 

EpiLP1985

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So, if I just don't want to geek out and I just need to know it a pickup is hot, what shall be done?

We don't really need lab tests, nor the exact experimentally controlled value for output, just to know if a pickup is a strong or a weak one

DC output is something anyone can do, and is pretty consistent in a lot of cases. As a matter of fact, it never failed me in telling a strong pickup from a weak one

Depending on the magnet type and strength, you can safely assume that for a range of pick hand inputs of soft to hard you will get comparatively higher output from a higher DCR.

There are many variables but like any hard science or math, you can make assumptions that simplify things.
 

Tom Wittrock

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Measuring RMS voltage is no more complicated than measuring resistance, you just connect up the meter in the same way, pluck the strings and read the output but as discussed the reading will depend on how hard the strings are plucked plus a bunch of other variables so it is pretty meaningless.

So, does this mean output can not be measured without a guitar string vibrating?

I would think there is a system to create a uniform [same every time] impetus for the pickup to respond.
 
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EpiLP1985

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So, does this mean output can not be measured with a guitar string vibrating?
I would think there is a system to create a uniform [same every time] impetus for the pickup to respond.

It can be measured it will just vary because the induced current changes with the vibration. You could measure output voltage from a soft and hard attack and then say your output range is between X and Y. You could also feed the pickup a mA range signal and plot the output. I did something similar in college when I wrote a technical report on the Rangemaster circuit. I setup a voltage source to mimic output from a guitar pickup circuit.

A simple model could be done in Excel that takes the basic specifications of the pickup and plots output voltage against a range of current values and a fixed resistance.

In general you can say that if we assume a fixed magnetic strength, that a fixed DCR that is higher will have greater output across a ranges of currents that one that is lower.

Obviously there are more complex answers than that but it gets you in the ballpark.
 

Wilko

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So, does this mean output can not be measured with a guitar string vibrating?
I would think there is a system to create a uniform [same every time] impetus for the pickup to respond.

That would not be impossible.

The standard for measuring speakers is real simple.

normally stated as the SPL, it's measured 1 metre in front of the speaker with 1 watt of power driving the speaker.
 

duaneflowers

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Even if it were possible to simply measure the output, what would that give us? A measure of loudness? A graphical representation of swell and decay? I don't think it would tell us much about the shape of the tone, which is largely derived from the shape of the coil, from which the tone we seek ultimately follows. A picture of the coils (like those shown below) only gives us part of the picture (like where the tape is buried), and physical differences in the wind... it doesn't equate directly to the shape of the tone. I think what we are ultimately looking for is a graphical representation of the pickup's tone which must first be defined before terms like bloom, weep, and awesomeness in all their subjective multi-dimensionality can be measured.

Definitely no easy task...

23551072_10213870913703581_3845166814664252920_o.jpg
 

EpiLP1985

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Even if it were possible to simply measure the output, what would that give us? A measure of loudness? A graphical representation of swell and decay? I don't think it would tell us much about the shape of the tone, which is largely derived from the shape of the coil, from which the tone we seek ultimately follows. A picture of the coils (like those shown below) only gives us part of the picture (like where the tape is buried), and physical differences in the wind... it doesn't equate directly to the shape of the tone. I think what we are ultimately looking for is a graphical representation of the pickup's tone which must first be defined before terms like bloom, weep, and awesomeness in all their subjective multi-dimensionality can be measured.

Definitely no easy task...

23551072_10213870913703581_3845166814664252920_o.jpg

I think you nailed it.

As far as DCR being a relatively effective landmark for potential output (voltage) I think that it serves that purpose pretty well so long as you put it into the proper context. If we can make the general assumption that, physically older or purposely de-gaussed magnets aside, most magnets of the same type will be magnetized similarly and that way we can assume the for a pickup with a higher DCR has the potential for higher output voltage.

As far as frequency response and tone are concerned, that could be analyzed and plotted over a range to give a general idea of how the pickups responds.

To me, output and tone quality require separate and equally interesting analysis.

What a great thread!
 

Tom Wittrock

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So, does this mean output can not be measured without a guitar string vibrating?

I would think there is a system to create a uniform [same every time] impetus for the pickup to respond.

should have read without, instead of with

It helps to proofread my post in the first few moments. :##
 

duaneflowers

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So, does this mean output can not be measured without a guitar string vibrating?

I would think there is a system to create a uniform [same every time] impetus for the pickup to respond.

You may be on to something... since pickups are essentially microphones I think any static sound can be passed through them (even outside of a guitar) and then the results examined for differences in that pickups unique 'flavor'... eliminating several 'pollutants' (picking strength, distance from strings, differences in individual guitar's acoustics, etc.).
 

Big Al

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I had a pair of untouched 59 paf's that barely measured above 7k. The original Shaw era paf's from 80-82 that I own are similar with resistance around 7.3k but a strong loud tone. ???? Everyone thought they sounded hot. I'd imagine output would be measured in millivolts under use, how I don't know.
 

springhead

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^^^ Exactly, the coil resistance isn't the only factor in determining how loud a pickup, or guitar sounds. Same way that a car with a 3L engine isn't necessarily faster than one with a 2L engine.

Question for pickup makers - say you wind a pickup with a set number of turns and pattern. You should be able to repeat that with a heavier gauge of wire but more turns to get a higher output yet lower resistance. Does that bear out in practice or do you end up filling the bobbin due to the larger diameter of the wire?

Use of coil resistance as an indicator of output has probably become too ingrained to change. But can we please not call resistance 'output'? And worse still 'DC output'. That really is nonsensical!
 

PaulD

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So, does this mean output can not be measured without a guitar string vibrating?

I would think there is a system to create a uniform [same every time] impetus for the pickup to respond.

As far as I know there is nothing available that will do this, I'm sure that it would be technically possible and relatively simple to produce some sort of device that could be placed on top of the pickup which would excite the magnetic field to a pre-set standard level but whether there would be sufficient demand to justify designing and producing such a device is another question.
 

springhead

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eBow! (joking, but that's the principle. And like all test equipment it would regular calibrating and authenticating to permit meaningful comparison with other peoples measurements).
 

EpiLP1985

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^^^ Exactly, the coil resistance isn't the only factor in determining how loud a pickup, or guitar sounds. Same way that a car with a 3L engine isn't necessarily faster than one with a 2L engine.

This is true but the issue is that, for the most part, once a current is induced in the coils the DCR is a big factor in the amount of output voltage produced and sent to the next stage in the circuit (Ohm’s Law). You are right, however, when you say that there are other factors in how much current is induced.

Question for pickup makers - say you wind a pickup with a set number of turns and pattern. You should be able to repeat that with a heavier gauge of wire but more turns to get a higher output yet lower resistance. Does that bear out in practice or do you end up filling the bobbin due to the larger diameter of the wire?

I think you meant smaller diameter wire = more turns = more resistance?

Use of coil resistance as an indicator of output has probably become too ingrained to change. But can we please not call resistance 'output'? And worse still 'DC output'. That really is nonsensical!

Well the output is essentially DC voltage in the mV range.
 

EpiLP1985

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I had a pair of untouched 59 paf's that barely measured above 7k. The original Shaw era paf's from 80-82 that I own are similar with resistance around 7.3k but a strong loud tone. ???? Everyone thought they sounded hot. I'd imagine output would be measured in millivolts under use, how I don't know.

Different magnets? Change in magnet strength maybe, over time?
 

springhead

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This is true but the issue is that, for the most part, once a current is induced in the coils the DCR is a big factor in the amount of output voltage produced and sent to the next stage in the circuit (Ohm’s Law). You are right, however, when you say that there are other factors in how much current is induced.



I think you meant smaller diameter wire = more turns = more resistance?



Well the output is essentially DC voltage in the mV range.


I mean that possibly a larger diameter wire could, with more turns applied, produce a higher output at lower resistance than a smaller diameter wire. Unless it becomes too big for the bobbin. Theoretically, hence pickup winders can confirm or not if that's practically possible.

And no, it will be an AC voltage in the 10's to 100' mV range. It's a wobbling string intersecting flux lines and inducing an alternating current in the coil. Not DC.
 

EpiLP1985

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And no, it will be an AC voltage in the 10's to 100' mV range. It's a wobbling string intersecting flux lines and inducing an alternating current in the coil. Not DC.

Right. Thank you for that clarification. Output voltage is an RMS measurement.

In fact, since the resistance in the coil has frequency components it's actually an impedance, so i'll wipe the egg off my face and regroup from some of my previous comments! Can't even trust an electrical engineer anymore...(maybe i'll stick to my day job and "big" wires)
 

PaulD

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Right. Thank you for that clarification. Output voltage is an RMS measurement.

In fact, since the resistance in the coil has frequency components it's actually an impedance, so i'll wipe the egg off my face and regroup from some of my previous comments! Can't even trust an electrical engineer anymore...(maybe i'll stick to my day job and "big" wires)

As you correctly say what the pickup actually presents to the amplifier is an impedance but what people typically measure and quote is the DC resistance of the coil.
 

EpiLP1985

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As you correctly say what the pickup actually presents to the amplifier is an impedance but what people typically measure and quote is the DC resistance of the coil.

You are absolutely right. I have been mis-speaking all over the thread about current and voltage though because I failed to make the resistance/impedance distinction. This led me to make uninformed claims about the nature of the induced current/DCR relationship.

Hence the yolk face!
 
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