# Technical question: Humbucker Pickup Output in mV's



## greco (Jul 15, 2007)

*I 'd like to understand more about the spec of "Output in mVs" as I don't remember seeing this in the past.

I read this spec in another thread and am curious to know why and how the output in mV's is measured and why it is a significant measure to provide?

Reference thread: http://www.guitarscanada.com/showthread.php?56585-DiMarzio-PAF-36th-with-PAF-PRO

Quote from internet: 

PAF DP103 Humbucker 36th Anniversary Guitar Pickup Specifications:*

Wiring: 4-conductor

Magnet: Alnico 5

*Output: 250mV*

DC resistance: 7.31

Year of introduction: 2008


​Cheers


Dave


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## Wild Bill (May 3, 2006)

greco said:


> *I 'd like to understand more about the spec of "Output in mVs" as I don't remember seeing this in the past.
> 
> I read this spec in another thread and am curious to know why and how the output in mV's is measured and why it is a significant measure to provide?
> 
> ...


Any amplifier has an input designed to accept a signal in a certain range of voltage amplitude, Dave. A line out to feed a power amp is nominally 1 volt of peak to peak AC. A magnetic phono cartidge for old LPS might deliver 10 mv and so the input on the back of a hifi receiver would be designed to accept that.

Obviously, if the input signal is going to be very small then you will need more stages of preamp tubes to amplify it up enough. That's why a tube power amp has fewer preamp tubes than a guitar amp, which as you have learned is expecting signals up to a few hundred mv.

The signal from the pickup is measured on a scope, since the input impedance is so high that a meter would likely load the signal down and make it appear lower. Besides, a meter can't react fast enough to show peak voltage from an audio signal.

Does this help?

Wild Bill/Busen Amps


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## Lincoln (Jun 2, 2008)

would it be correct to assume that a "dirty" or distortion humbucker would have a higher mV rating than a "clean" pickup?


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## LydianGuitars (Apr 18, 2013)

Yes, a higher output pickup drives the amp's front end harder, which in turn, might lead to more distortion, depending on the guitar and amp.


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## greco (Jul 15, 2007)

Wild Bill said:


> *The signal from the pickup is measured on a scope,* since the input impedance is so high that a meter would likely load the signal down and make it appear lower. Besides, a meter can't react fast enough to show peak voltage from an audio signal.
> 
> Does this help?
> 
> Wild Bill/Busen Amps


Thanks Wild Bill. 

I assumed that measurement would likely be done using a scope, but I wasn't sure.

I searched for more information on this topic and found several threads. It seems that the concerns regarding the use of this measurement revolve around consistently duplicating the test/measurement conditions (specifically among suppliers), the practical/applied benefit(s) of knowing this measurement for purposes of comparing pickups and/or providing any form of valuable information about the pickup (i.e., "loudness") and the inability to directly correlate the mV measurement to DC resistance and inductance. 

As expected, the threads go on and on with opinions and the well known fact that there are too many variables for this mV measurement to have any "real" benefit to the consumer. The only real test is that of the human ear....back to the land of total subjectivity...LOL.
(Note: This is my "conclusion" after reading several threads)

https://www.google.ca/search?q=mV+m...=chrome.0.57.16077j0&sourceid=chrome&ie=UTF-8

Cheers

Dave


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## jb welder (Sep 14, 2010)

greco said:


> am curious to know _*why and how the output in mV's is measured*_ and why it is a significant measure to provide?


I'm sure you've heard the term "hot" in regard to pickups. The mV measurement is about the only way to determine what is a "hotter" pickup.
Unfortunately, there doesn't seem to be any real standard for testing, so the numbers are fairly general. Hitting the strings harder when measuring will exaggerate a pickups output level. But the numbers will give you an idea of how hot a pickup is.
http://www.seymourduncan.com/support/find-your-tone/understanding_output/ (I think looser is typo for lesser)
http://www.blueguitar.org/new/misc/pickup_mv_chart.pdf


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## greco (Jul 15, 2007)

jb welder said:


> I'm sure you've heard the term "hot" in regard to pickups. *The mV measurement is about* *the only way to determine what is a "hotter" pickup*.


What is the best indication of how "hot" a pickup is?
DC resistance? Inductance in Henries? or mV output? 
These specs do not always correlate!

What is the definition of "hot" ? .... Is it simply "loudness" ?

Cheers

Dave


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## dcole (Oct 8, 2008)

Here's my two cents. 

I think the mV output of the pickup is useless. Having scoped my own guitars in the past, I have seen a large voltage on the string attack and a much lower voltage while the string is sustaining. I have a guitar that puts out up to 5V peak on the initial transient. Before even measuring this I always though the guitar had hot pickups because it easily distorts pushed tube amps and usually distorts anything digital when played hard.

I can say with confidence that the wall plug puts out ~ 120 Vrms as its basically a simple sine wave that can be measured easily and accurately. I can not say that a pickup has a specific mV output as it is a complex signal.


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