Wednesday, December 31, 2014

Electric Guitar Output Voltage Levels

I was recently interested in how much output voltage you get from guitar pickups. To find out, I connected a guitar to an oscilloscope and did some measurements. Here are the numbers:


  • The values are peak voltages in millivolts (double the values for peak-to-peak)
  • The 'A' values represent the maximum transient peak voltage I observed (just after the string leaves the pick)
  • The 'B' values are measured after about two seconds into the tone.
  • I picked (strummed) hard. That's obviously a very subjective statement. Your mileage will vary.
  • The values are averages over three to five repetitive measurements.
  • The scope used has an input impedance of 1MOhm and an input capacity of 18pF. Probe attenuation was at 1X.
The guitar I used has a volume control and a tone control. For the measurements, volume was on maximum output and the tone control was on minimum impact.

I used the following pickups:
  • Single coil (neck and middle): GFS Pro-Tube lipstick
  • Humbucker (bridge): Artec Vintage Humbucker LPC210N
The measured DC series resistance of the pickups are as follows:
  • Neck: 4.8K
  • Middle: 6.2K
  • Neck & middle (parallel): 2.7K
  • Neck & middle (series): 10.9K
  • Humbucker: 8.3K
The difference between soft, medium-hard and hard picking was in my case about a factor of 2 to 3. Meaning: picking the open A string softly I got about 10mV, medium-hard 20mV and hard 30mV (which you'll find under 'A' in the table, above).

And here the screenshots referred to in the table:

a.bmp - neck pickup, open A string.

b.bmp - neck pickup, open E chord. This is one of the lower samples. Most other measurements came in higher.

c.bmp - bridge humbucker, open A string.

d.bmp - bridge humbucker, open E chord.

6 comments:

  1. This is very helpful, thank you!

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  2. Excellent work and very useful. Well done.

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  3. Very useful information - thank you.

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  4. Saved me the test with Humbucker pick which I do not own.
    I did not realized that it produces at least 3 times stronger signal.
    Now I know why some preamps have the 10dB attenuator switch. This must be to match the gain to Humbucker pickups.
    Thanks a lot

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