B How does output voltage of an electric guitar work?

[Xenon02]

Hello !

I've got a problem understanding the pickup ? or the sound ? I don't know I got very confused. I wanted to learn how to make guitar effects although I don't know much about music but I wanted to make. On this website : https://sound-au.com/articles/guitar-voltage.htm Here the Peak voltages of E1 is 100mV and E2 is 300mV, the thing is when there is a chord, I guess it is a E1 and E2 played at the same time so E1 + E2 is 300mV it is the same as single E2 which is also 300mV. That doesn't make any sense to me ... So single string makes E1 sound, and another single string makes E2 sound but playing both strings E1 and E2 makes the same sound as E2 ??????

Second thing is my experimentation. I know about interference and phase shift of the signals. But interference means that the sinewaves must add up to each other right ? Here are the images and the link : https://www.geogebra.org/graphing/merap3ws, so the orange function is the sum of 3 sinewaves (f(x),g(x),h(x)). So f(x) is let's say E1, g(x) is E2 and h(x) is E3 so we have 3 strings (guitar has 6 strings the classic one).
We play all 3 string at the same time so we have 3 sinewaves adding to each other sometimes the sum exceeds value "1" which here it is "3". How does the pickup makes these sound into voltages ? for peak sound "1" it is 0.7V or for peak sound of "3" it is 0.7V ? The maks that pickup can make is 1V but I said 0.7V because it is easier. How does it work ??? What if we have sound that has "20" as a value how does the pickup changes the sound sinewaves into voltage sinewaves ?

Hence I couldn't understand why the output of the guitar is maks 1Vpp or 1V I guess ?

I got so lost because these sums are exceeding this value of "1" and how the pickup "knows" what is the pick of the sound or when he uses maks voltage, when the sound peak is "300","3000" etc ? The sums of the sinus can be alot.

PS. If it's possible to make is simple for goofball like me.

 

[gmax137]

I think @pinball1970 is a guitar player, maybe he can help here.

 

[Xenon02]

I think @pinball1970 is a guitar player, maybe he can help here.

Yea would be helpfull because I just don't get it how the pickup works, because I have some interference knowladge and I shown the pictures of how the sinus can add up and have peak value like "3", "10", etc. but how the pick up works and "knows" what is the maks amplitude and changes it into maks amplitude in voltage instead of maks sound wave amplitude. If what I said makes any sense at all.

;>>>>

 

[berkeman]

Here is a good article on how electric guitar pickups work: https://www.yamaha.com/en/musical_instrument_guide/electric_guitar/mechanism/mechanism002.html

Also, when you are adding multiple sine waves of different frequencies, it is usually the RMS values that you add, not the peak values. You would only add peak values if they were coherent sine waves of the same frequency and phase.

More background on mixing sounds of different phases and frequencies: https://nsinstruments.com/principles/linear.html

 

[pinball1970]

I think @pinball1970 is a guitar player, maybe he can help here.

Drummer but I do hang around with those guys. I'll pass it on.

 

[Drakkith]

Yea would be helpfull because I just don't get it how the pickup works, because I have some interference knowladge and I shown the pictures of how the sinus can add up and have peak value like "3", "10", etc. but how the pick up works and "knows" what is the maks amplitude and changes it into maks amplitude in voltage instead of maks sound wave amplitude. If what I said makes any sense at all.

;>>>>

A simple explanation: The pickup is just a transducer. For a guitar, the pickup magnetizes the guitar strings and the motion of the strings then induces a voltage in the coil inside the pickup. This voltage is then passed through a circuit where it is ultimately amplified and sent to a speaker or some other device for playback and/or recording.

The pickup itself 'knows' nothing. It merely responds to the changing magnetic field produced by the vibrating strings. It does no adding of frequencies or anything else. The maximum amplitude is determined by the strength of the magnetic field of the strings and how quickly it is changing, which is proportional to the how fast the strings move. To be honest, the peak amplitude of the voltage signal is mostly irrelevant. As long as the signal is strong enough to be amplified effectively without undo noise then the peak amplitude doesn't matter. If it's a little too low then you just turn up the volume knob and vice versa.

Also note that there is no sound wave mentioned here. This is because the pickup does NOT detect sound waves in air. It directly detects the motion of the strings. You could, of course, use a microphone to detect sound waves in the air, such as what you would do to record someone playing an acoustic guitar without any pickups, but that's not how an electric guitar works.

 

[gmax137]

Drummer

arghh sorry, I do know that. I remember your posts about playing gigs and the ones about "original or cover"

 

[Xenon02]

Also, when you are adding multiple sine waves of different frequencies, it is usually the RMS values that you add, not the peak values. You would only add peak values if they were coherent sine waves of the same frequency and phase.

They do not add up ? Is it not like interference ? Why ?
Sounds a bit weird because usually learning about amplitude of waves meeting at some point interfere with each other.

Same goes to RMS, why RMS ? The waves meet at some point and that point is being interfered so peaks or some part of that signal is being interfered. In the article I sent showed some signals and their RMS and peaks.

A simple explanation: The pickup is just a transducer. For a guitar, the pickup magnetizes the guitar strings and the motion of the strings then induces a voltage in the coil inside the pickup. This voltage is then passed through a circuit where it is ultimately amplified and sent to a speaker or some other device for playback and/or recording.

The pickup itself 'knows' nothing. It merely responds to the changing magnetic field produced by the vibrating strings. It does no adding of frequencies or anything else. The maximum amplitude is determined by the strength of the magnetic field of the strings and how quickly it is changing, which is proportional to the how fast the strings move. To be honest, the peak amplitude of the voltage signal is mostly irrelevant. As long as the signal is strong enough to be amplified effectively without undo noise then the peak amplitude doesn't matter. If it's a little too low then you just turn up the volume knob and vice versa.

So how each note are distinguished ?
Can I add up individual 2 signal and will give me the same result as 2 signals played at the same time.

Let's say I play E1 and this is one signal, then I play E2 and this is second signal and at the end play E1 and E2 at the same time. Adding the results of individual E1 and E2 gives me the same signal of E1 and E2 played at the same time ?

Because if I want to amplify some sound like E1 I have to somehow exclude him from the sound signal that contains all the sounds/signals. Od does superposition work here ?

Also note that there is no sound wave mentioned here. This is because the pickup does NOT detect sound waves in air. It directly detects the motion of the strings. You could, of course, use a microphone to detect sound waves in the air, such as what you would do to record someone playing an acoustic guitar without any pickups, but that's not how an electric guitar works.

Aha so my thinking of the sound waves is pretty useless here, because if it was sound wave then the peaks of Sound are a bit questionable because they can exceed some value like I showed in geogebra. Or maybe that is also a bad thinking even for microphone because the signals should interfere like in my pictures resulting in high amplitude peaks !!!

But yea so if the pickup works a bit different and the amplitude is determined by the vibration but what about distinguishing the sounds ? Does the superposition work ? Or rather how pickup creates complex signal when many Strings wibrates. If superposition works then maybe pickups gives the final results only, but still consist of all sound and can be distinguished using superposition. Separate sounds equal to the sum of these sums.

Maybe I am right or not ;>

PS.

Isn't the vibration some sort of Sound wave ? It must be also a sinus so it shows the same problem maybe when it comes to adding sinuses up.

Or like why the sound from pick up that add up doesn't exceed the 0.7V maks when individuals can have 0.3V in my geogebra I've shown that adding 3 signals can exceed huge value let's say single sound from string makes 1V so 2 sound with different frequencies makes sound that there is a peak exceeding 1 V. Weird.

 

[Xenon02]

https://www.informit.com/articles/article.aspx?p=2355856&seqNum=5

Here I have found something interesting.
The author says that sound that add up using superposition and scales it to +1 and -1 so even if we have a sound that exceeds the value 1 after superposition it is scaled back to +1 and -1 as if adding more sound at the same time makes all individual sound smaller than originally.

Let's say I play E1 and the E2 they have amplitude of 0.3V but if I play E1 and E2 at the same time the final result is the same but E1 and E2 have smaller amplitude than the individual sounds.
Weird that adding sounds reduced their individual amplitude.

PS.
Although here the two so waves added exceeds value "1" and aren't scaled to +1 and -1. So I am lost here when it comes to exceeding some value of amplitude. Or how superposition works in pickups or how Vibration that is similar to the sine wave sound because it creates the sinus signal must add up but never exceeds value 1V wierd

 

[Drakkith]

So how each note are distinguished ?
Can I add up individual 2 signal and will give me the same result as 2 signals played at the same time.

What I'm getting at is that the pickups simply turns the motion of the strings into a voltage signal. The string itself is what is moving. Distinguishing different frequencies takes place in your ear or when you pass the signal through the appropriate circuit.

Let's say I play E1 and this is one signal, then I play E2 and this is second signal and at the end play E1 and E2 at the same time. Adding the results of individual E1 and E2 gives me the same signal of E1 and E2 played at the same time ?

Yes.

But yea so if the pickup works a bit different and the amplitude is determined by the vibration but what about distinguishing the sounds ? Does the superposition work ? Or rather how pickup creates complex signal when many Strings wibrates. If superposition works then maybe pickups gives the final results only, but still consist of all sound and can be distinguished using superposition. Separate sounds equal to the sum of these sums.

Ideally the pickups should only pick up the motion of one string each. But even a single string will not vibrate at a single frequency thanks to overtones, so you will never have a pure sine wave signal. And again, the pickup is not doing any frequency summing or anything else. It simply responds to the movement of the string with an output voltage. The physics of the string itself determines how it vibrates and gives it all of the different frequencies when plucked.

Edit: Apparently I was incorrect about each pickup only detecting the motion of one string. My point about the pickup detecting the motion of the string is true, and I suppose you could call this frequency summing. But I'm not an expert in this topic.

The author says that sound that add up using superposition and scales it to +1 and -1 so even if we have a sound that exceeds the value 1 after superposition it is scaled back to +1 and -1 as if adding more sound at the same time makes all individual sound smaller than originally.

That's a choice by the programmer. Physical waves (as in waves in the real world, not in a computer simulation or formula) do not automatically scale in this manner. In fact, you can see this in Berkeman's link in post #4.

Let's say I play E1 and the E2 they have amplitude of 0.3V but if I play E1 and E2 at the same time the final result is the same but E1 and E2 have smaller amplitude than the individual sounds.
Weird that adding sounds reduced their individual amplitude.

Unless you are artificially scaling the sum of the two tones in some manner then they will not have reduced amplitude. Indeed conservation of energy forbids it. Imagine 100 violinists playing slightly different notes. It's going to be LOUD despite the fact that the notes are all different.

 

[Baluncore]

Ideally the pickups should only pick up the motion of one string each.

The metal imaginary "pickups" are magnets that magnetise the string. There is one coil wound about all the magnets that detects the movement of any magnetised strings. All the string signals are summed in the one coil.

That system is linear, so the fundamentals and harmonics present, are all added together. If you consider every frequency present in the signal, and measure the RMS amplitude of each, with an FFT for example, you can estimate the power of each frequency.

The sum of those is the power in the combined signal. Although it will have rare extreme peaks, the RMS voltage of the combined signal, will represent the same power as the sum of all the individual frequencies. The mistake is to focus on a single momentary spike, when you should be squaring and averaging.

A guitar amplifier will distort and cross modulate everything to some extent. The amplifier front-end is designed to be non-linear. Why else would they use a 12AX7 when they could generate less harmonics with a 12AU7.

 

[Drakkith]

The metal imaginary "pickups" are magnets that magnetise the string. There is one coil wound about all the magnets that detects the movement of any magnetised strings. All the string signals are summed in the one coil.

Ah, my mistake. I was under the impression that there was a separate coil for each string. I should have checked before I said something.

 

[Xenon02]

Ideally the pickups should only pick up the motion of one string each. But even a single string will not vibrate at a single frequency thanks to overtones, so you will never have a pure sine wave signal. And again, the pickup is not doing any frequency summing or anything else. It simply responds to the movement of the string with an output voltage. The physics of the string itself determines how it vibrates and gives it all of the different frequencies when plucked.

But the motion of a string is a sin wave with a frequency. Bounces up and down at specific speed like sine wave.

That's a choice by the programmer. Physical waves (as in waves in the real world, not in a computer simulation or formula) do not automatically scale in this manner. In fact, you can see this in Berkeman's link in post #4.

I saw the Berkeman's link and it shows that the two sound signals surpassed the value peak of "1". So how the pickup reduces it so it sounds the same.

What if the whole sound made of many sounds like 20 frequencies added to each other made that peak value is not "1" but "10" and the smallest value is "2" so the pickup sees that maks value is "10" and smallest is "2" so the output will be just a constant 0.7V output xD.

There must be some correlation to the sound value because adding each frequency must make some difference when the amplitude exceeds the values. Adding more frequencies will exceed the peak and the lowest value even more.

The metal imaginary "pickups" are magnets that magnetise the string. There is one coil wound about all the magnets that detects the movement of any magnetised strings. All the string signals are summed in the one coil.

That system is linear, so the fundamentals and harmonics present, are all added together. If you consider every frequency present in the signal, and measure the RMS amplitude of each, with an FFT for example, you can estimate the power of each frequency.

The sum of those is the power in the combined signal. Although it will have rare extreme peaks, the RMS voltage of the combined signal, will represent the same power as the sum of all the individual frequencies. The mistake is to focus on a single momentary spike, when you should be squaring and averaging.

A guitar amplifier will distort and cross modulate everything to some extent. The amplifier front-end is designed to be non-linear. Why else would they use a 12AX7 when they could generate less harmonics with a 12AU7.

As I thought the sounds are summed in the coil.
But creating a circuit for the guitar like op amp I must know the exact input values but if there is a peak exceeds 1V but usually it is said maks is 1V then I dunno how the vibrations sinus that are similar to sound sinus exceeded the value "1" like in Berkeman's last link in post #4 then I don't get it as well as why using RMS and not care about peaks ? If peak is like "10" and minimum value of the signal is "2" which is larger than "1" and can happen because there are many frequencies added up.

And can result in Output constant voltage of 0.7V because pickup can maks do 0.7V or 1V. And watching the individual sound like E1 and E2 like in my link from post#1 still makes no sense why it is still under 0.7V but the sound can easily exceed "1" as same goes to vibration which vibrates up and down like sinus wave with fixed frequency.

I dunno I still don't get this part or problem when I can see that the values of 2 strings exceeds the value of "1" and what if I had more sinus waves. Same goes with the first link of post #1 where separate E1 and E2 aren't exceeding "1" weird or chord which is pulling 6 strings so 6 sounds it must exceed "1" but still maks is 0.5V or lower ??? Weird.

 

[Drakkith]

But the motion of a string is a sin wave with a frequency. Bounces up and down at specific speed like sine wave.

Real strings do not vibrate at a single frequency. They have many different frequencies called the normal modes, where the lowest frequency of the normal modes is called the fundamental frequency and all the others are the overtones.

I saw the Berkeman's link and it shows that the two sound signals surpassed the value peak of "1". So how the pickup reduces it so it sounds the same.

The pickup doesn't reduce anything. It simply outputs a voltage based on the motion of the strings. Different notes can produce a large range of voltage outputs. For example, in the reference in your first post, the measured RMS voltage output in the first table of results varies between 12 mV and 128 mV depending on the note/chord and the pickup position. And this was in a controlled experiment. A real guitar would probably be subject to a much larger difference in min-max voltages depending on playstyle and such.

I've got a problem understanding the pickup ? or the sound ? I don't know I got very confused. I wanted to learn how to make guitar effects although I don't know much about music but I wanted to make. On this website : https://sound-au.com/articles/guitar-voltage.htm Here the Peak voltages of E1 is 100mV and E2 is 300mV, the thing is when there is a chord, I guess it is a E1 and E2 played at the same time so E1 + E2 is 300mV it is the same as single E2 which is also 300mV. That doesn't make any sense to me ... So single string makes E1 sound, and another single string makes E2 sound but playing both strings E1 and E2 makes the same sound as E2 ??????

I wouldn't take these results as being 100% accurate. Without some machine to physically pluck the strings such that they vibrate the same for each test the results must be taken with a grain of salt. To quote the article:

"I tried to be as consistent as possible, but it's not easy. Every time you strike (or pluck) a string it will be a wee bit different. While it might sound very similar, the oscilloscope is totally unforgiving, and will show every tiny difference in the harmonic structure and the overall wave-shape. It's not really feasible to take many waveforms from each string and try to generate an average, as one ends up with a vast number of files that must be relevant to each test. This gets very messy, very quickly."
And:

"The oscilloscope shows the RMS level averaged across the full four second sweep, and while it's not particularly accurate, it is a useful indicator of what you can expect."

 

[Xenon02]

The pickup doesn't reduce anything. It simply outputs a voltage based on the motion of the strings. Different notes can produce a large range of voltage outputs. For example, in the reference in your first post, the measured RMS voltage output in the first table of results varies between 12 mV and 128 mV depending on the note/chord and the pickup position. And this was in a controlled experiment. A real guitar would probably be subject to a much larger difference in min-max voltages depending on playstyle and such.

Okey but the pickup interprets high amplitude of the vibration ?
Like I've said before and looking at some pictures the amplitude of a sound/vibration exceeds the value "1" when there are multiple sounds/vibrations. How the pickup will interpret the vibration of a amplitude which pik is "100" in value and how it will interpret the different sound of a amplitude of value "10" ???

The amplitude value is inconsistent to what max pickup value can give. And the pickup is recreating the sound the strings vibrate. So the sound from vibration is the same at the voltage we get atleast the shape is similar/same. So what about the amplitude of vibration which is similar to sound because they add up so they exceed value "1" like "100" or lower but still how pickup interprets them ?

 

[sophiecentaur]

They do not add up ? Is it not like interference ? Why ?

The term "interference" is normally used to describe a spatial effect as two or more signals (the same or very very near same frequency) contribute to the effective signal at different points. (Look up Young's Slits) What you get from one or more strings is just a number of signals at different frequencies coming down the same wire. Our ears interpret this as beats or just pleasant / unpleasant total sounds. Non-linearities (fuzz boxes / valve amplifiers etc ) generate new frequencies and (like the toothpaste out of the tube) will not go back into the original form.
But it's just a word and is often used in alternative ways outide of wave theory

 

[Xenon02]

The term "interference" is normally used to describe a spatial effect as two or more signals (the same or very very near same frequency) contribute to the effective signal at different points. (Look up Young's Slits) What you get from one or more strings is just a number of signals at different frequencies coming down the same wire. Our ears interpret this as beats or just pleasant / unpleasant total sounds. Non-linearities (fuzz boxes / valve amplifiers etc ) generate new frequencies and (like the toothpaste out of the tube) will not go back into the original form.
But it's just a word and is often used in alternative ways outide of wave theory

Doesn't the sound add up ? I read something about superposition of Sound so I assumed it is something like Interference. That these sound add parts where they meet at like in my geogebra example.

But I still wonder how pickup works when the sum of all amplitudes from sound or vibration exceeds this value "1". Like the sum of all signals is "100" and what pickup will do with this peak. Or with many peaks because I said about one peak but what if I have many peaks or the single peak is very long.

This huge value from the vibration when the signals are summed is something that I can't imagine how pickup interprets it.

 

[Baluncore]

The amplitude value is inconsistent to what max pickup value can give. And the pickup is recreating the sound the strings vibrate. So the sound from vibration is the same at the voltage we get at least the shape is similar/same. So what about the amplitude of vibration which is similar to sound because they add up so they exceed value "1" like "100" or lower but still how pickup interprets them ?

You really are confusing yourself.

The signal from the pickup, is the voltage between two wires, that appears across the resistance at the input to the amplifier. That voltage is the linear sum of all the movement, of all the strings, many different frequencies and each of those with a different amplitude varying with time.

Power is proportional to the square of the voltage. So we square the voltage, then take the mean, which will be positive. That mean is proportional to the power. We can find the equivalent positive voltage by taking the square root. That is why the voltage amplitude of an AC signal is called the RMS voltage, the Root of the Mean Square of the voltage.

If you take the combined signal, and measure the power of each frequency separately, they do sum to the total power of the combined signal.

Because energy is conserved, it is the square of voltage that is important.
When; a² + b² = c² ; it does not follow that; a + b = c .
The peak voltage amplitude of the combined signal is misleading, because you are summing in the voltage domain, not the power domain.

 

[Xenon02]

Because energy is conserved, it is the square of voltage that is important.
When; a² + b² = c² ; it does not follow that; a + b = c .
The peak voltage amplitude of the combined signal is misleading, because you are summing in the voltage domain, not the power domain.

I still don't get it.
Why power now ? I mean I wanted to use this voltage from pickup for some guitar effect so to create electronic circuit so I have to know what is the input voltage rather than power I guess ?

But mainly let's use an example, because it might get easier.

This is the vibration of 4 sounds. The peak is "4" (I don't know the unit of the sound/vibration so I just say "4"), it consist of 4 sounds so adding them will result in this orange signal. It is correct to the superposition linked in post #9.

- So is this orange signal a power ?
- Will the pickup voltage signal will be similar to this orange signal ?
- What will pickup do to this "4" peak ? What will be the value in voltage of that peak ?
- Will a different peak like "10" have similar voltage value like "4" peak ?
- What has power domain to the voltage domain ? If orange signal is in power domain so square root of that top value will result in "2" (I might be wrong here).

- here I saw something about RMS but still peak is "4" RMS = +/- 2.8. It's a mean value in AC because normally mean value of the sine is 0, but yea RMS is a mean value for AC signals.

So I wanted to understand it using an example. Example that some sources provided like superposition of 2 signal and more or the link of the voltage value from the 1st post. I just wanted to know what pickup does to very high peak values.
Or maybe you are telling me this, but I just don't find it connected to my question or something. Because I asked about what happens to the peak and I read about power ;D Don't get me wrong here I just don't get the explanation because for sure I can't properly ask a question or my examples aren't clear so yea ;D

 

[Baluncore]

So is this orange signal a power ?

No, it is a sinusoid that goes negative, so it is not power.

- What will pickup do to this "4" peak ? What will be the value in voltage of that peak ?

The instantaneous voltage is 4.

- Will a different peak like "10" have similar voltage value like "4" peak ?

I have no idea what that sentence means. "10" what, "4" what?
A number without units is meaningless.

 

[Baluncore]

I just wanted to know what pickup does to very high peak values.

If it is linear, it does nothing to them.

The peaks are nothing special, they are just coincidences in time of positive voltages. But they have fascinated your mind, and are now a distraction from everything that is important.

Plot a sinusoidal signal voltage.
Plot the square of that signal voltage. You will get a sinusoid, above the x-axis, with double the original frequency, that represents energy flow.
Now integrate that squared signal, divide by time, and you have the power of that original signal.

 

[Xenon02]

I have no idea what that sentence means. "10" what, "4" what?
A number without units is meaningless.

I mentioned I didn't know the unit :

This is the vibration of 4 sounds. The peak is "4" (I don't know the unit of the sound/vibration so I just say "4"), it consist of 4 sounds so adding them will result in this orange signal. It is correct to the superposition linked in post #9.

I just saw on the videos the peak value of the sound which in my geogebra example is "4", without units, because I didn't see any in video/website etc. I only saw the final result which is my orange signal.

But I see that the part of voltage you've understood what did I mean by "4" or I guess you've understood. I just used the value from the example of that orange signal. And what did I mean by "10" ? Is what if peak value of that orange signal was not "4" but "10". So sound/vibration signal peak is equal to voltage peak value ? So vibration peak is "4" so voltage signal peak is also 4V ? Doesn't make that much sense though. So if the vibration peak value is "100" then the pickup will change that "100" peak into 100V peak voltage value.

The instantaneous voltage is 4.

The max voltage value from pickup can be 1V or 0.7V so how is it that instantaneous voltage is 4 ?

So indeed the sound/vibration signal will look the same as voltage signal from pickup, so pickup getting the orange signal will make the same looking signal but in voltage. I guess.

 

[Averagesupernova]

@Xenon02 i suspect you are getting confused for several reasons. The first is that doubling voltage does not equate doubling power. You need to realize that a vibrating string is being represented as a voltage. Doubling voltage quadruples power. Striking two strings instead of one is not quadrupling power. Math doesn't lie.

 

[Xenon02]

@Xenon02 i suspect you are getting confused for several reasons. The first is that doubling voltage does not equate doubling power. You need to realize that a vibrating string is being represented as a voltage. Doubling voltage quadruples power. Striking two strings instead of one is not quadrupling power. Math doesn't lie.

That's why I used example to see it.
What power ? What doubling ? Where did I confused/said that doubling the voltage equals doubling power ? I just showed what vibrating string gives which is the orange signal. How the pickup interprets the orange signal received from vibrating strings into voltage signal ? I sit the same ? How it interprets the peak of that vibration when it's value is "4" (I don't know the units).

The pickup receives the whole orange signal with this peak value of "4" and must transfer it into equivelant of the voltage signal. Pickup maks output voltage can be 1V. And pickup receives the input signal from vibration so the magnetic field movement and transfers this movement into voltage.

I still don't get it, so that's why I used the example so it would be clearer for me if it was used or rather say what is wrong or confusing in my text because I often refer to peak values of the input signal from vibration/sound wave received by the pickup, and how pickup interprets that input and makes it into output what happens to the peak value of "4" from then input when the max output signal can be 1V or 0.7V.

I don't know what do you mean by power here when I see only orange signal that is not the power nor the voltage signal it is just the input for the pickup that is made from the vibration, the sum of these vibrations is the orange signal so the pickup must change this input into voltage output. But the input has some high peak values which is "4" or can be "10", "1000" etc. But the pickup can have maks 1V output.


It is not logical that the peak values received by pickup doesn't match up with the output voltage. I don't see it. Neither I don't know where the power here shows up in the signals I just use the whole signal and not the mean value so I don't understand why power came up here, when I was talking about input and output signals. In which output is voltage signal and the input is the vibration signal both have the same shape but different amplitude.

 

[Averagesupernova]

How it interprets the peak of that vibration when it's value is "4" (I don't know the units).

So if you don't know the units how can you expect it to make sense if you don't know whether the units is watts (power) or volts? That is assuming you accept that what I said is true about doubling voltage is quadrupling power.

 

[Xenon02]

So if you don't know the units how can you expect it to make sense if you don't know whether the units a watts (power) or volts? That is assuming you accept that what I said is true about doubling voltage is quadrupling power.

I don't know if it's true about power and voltage.
I just said how the sinewaves looks like based on these links https://nsinstruments.com/principles/linear.html , , https://physics.stackexchange.com/questions/495511/vibration-in-a-guitar-when-playing-two-strings (here it shows how it looks like the sinuses of the vibration).

So I don't know the units I just accepted the peak value of those vibrations so I wondered how the pickup resolves this problem, the peak is high but there is no unit. So I don't know how to understand it differently when I see many websites mentioning about superpositions and these examples of sound in which it exceeds this mystical value "1" without unit in Y-axis of the function. So I just took it as an input value which peak is of value "4".

Whether the double the voltage gives the quadruple power. Maybe you tried to say that me accepting that this value does something is the same as accepting your statement ?

If so then how should I interpret the input signal values ? And how the pickup uses these values of that input signal like in my example, how to interpret this peak value of "4" of that orange signal ? How the pickup will interpret it ? As I said I just did what in other websites/videos did. So I am trying to use the example to understand it because without it I am lost.

 

[Averagesupernova]

Trust me. If you have a voltage driving a constant resistance you will dissipate X watts in the resistor. If you double the voltage you will dissipate 4X watts in the resistor. So whether you are displaying watts or volts makes a difference.
-
The power it took to make the string vibrate is X watts. Do that with two strings at the same time requires 2X watts. Now the string and transducer are not 100% efficient but there will be a fraction of that power that is transmitted from the transducer. If you measure the voltage it will NOT BE twice the RMS voltage with two strings compared to one. I have told you why several times.

 

[Xenon02]

Trust me. If you have a voltage driving a constant resistance you will dissipate X watts in the resistor. If you double the voltage you will dissipate 4X watts in the resistor. So whether you are displaying watts or volts makes a difference.
-
The power it took to make the string vibrate is X watts. Do that with two strings at the same time requires 2X watts. Now the string and transducer are not 100% efficient but there will be a fraction of that power that is transmitted from the transducer. If you measure the voltage it will NOT BE twice the RMS voltage with two strings compared to one. I have told you why several times.

Could you tell me then what my orange signal represents ? Because I guess this is an input from vibration yes ?

Because for now I understand that 1 string is X watts and 2 strings is 2X watts. So 1 string = X watt = voltage, 2 strings = 2X watts = not 2*voltage, not 4*voltage it is <2*voltage.

So why in websites it showed the sum of those sinuses and the peak values etc where that high, if I can know.
I also understand that 4x watts = 2*voltage (RMS and PEAK) ?

Again then what my signal represents ? And is it correct ? What will pickup do to this signal ?

 

[Xenon02]

https://nsinstruments.com/principles/linear.html this links shows signal that his maks value is 1.5

So It doesn't have units so I don't know what it is then. Or rather how to interpret it when you've said that 2xPower = 2 strings, here are 2 strings let's say stroke.

Similar with my example from post # 19. So yea how to interpret those ?

 

[Averagesupernova]

I don't know what your orange line represents and I'm not going to bother trying to find out. This is your project and if you are unable to conclude what you are looking at then you have no chance of designing circuits to create guitar effects. I assume based on your first post that this is what you want to do.
-
Ohms law should tell you what you need to know assuming you know how to apply it concerning volts vs watts in your plot.
E=IR
P=IE
The other formulas that are commonly known and used can be derived from the above two.

 

[Averagesupernova]

Incidentally power would never swing positive and negative driving a resistive load. What you are looking at and where you got the images you posted I have no idea.
-
They may be ok for showing the basics of how things cancel and add. I wouldn't trust them for absolute accuracy.

 

[sophiecentaur]

Doesn't the sound add up ? I read something about superposition of Sound

Absolutely But what "adds up" is the instantaneous volts (amplitudes) of each waveform. It's a linear system. At times, the voltages add in phase, which can give you a resultant value of up to 2v which corresponds to four times the instantaneous Power. But the mean power is just twice the Power.

Addition of Powers and Voltages is a constant source of confusion if we don't go back to basics.

 

[Xenon02]

I don't know what your orange line represents and I'm not going to bother trying to find out. This is your project and if you are unable to conclude what you are looking at then you have no chance of designing circuits to create guitar effects. I assume based on your first post that this is what you want to do.

What I tried to represent with my orange signal/line is that the signals add up like in the links I've provided :
https://nsinstruments.com/principles/linear.html , and from stackoverflow : https://physics.stackexchange.com/questions/495511/vibration-in-a-guitar-when-playing-two-strings in which you can see that the final signal looks like :

It is not voltage it is the vibration/sound wave. So This is what pickup receives and it doesn't calculate with the math you've said. Or as far I know. I'm not trying to the one who annoys everyone. I just see some conflicts in the logic of voltages and the input the pickup receives like the blue signal I sent now or my orange signal. The peak values where the thing that worried me because how a peak value from the sound is now received by pickup which maks voltage he can make is 1V ...

No one in the links says a word about what it is other than that is a sound/vibration wave/signal.

Dunno how these equations will help me or how to use it in practice.
I saw some guitar effects like : Distort and they just assumed that input is max 0.7V peak. So yea. I wanted to understand more because logically it didn't have any sense why 0.7V is max (from tutorials I took this value or from this website : https://sound-au.com/articles/guitar-voltage.htm), because the sound/vibration signal can exceed huge values so I didn't know how these two correlate.

Incidentally power would never swing positive and negative driving a resistive load. What you are looking at and where you got the images you posted I have no idea.

That's why I've sent links from where I've read it to make sure if I am right or not or to understand what is going on. Because my main knowledge comes from these websites and other websites says/shows the same graphs. So I tried to understand though.

So all the links are in the post # 26 check it up if it's possible.

Absolutely But what "adds up" is the instantaneous volts (amplitudes) of each waveform. It's a linear system. At times, the voltages add in phase, which can give you a resultant value of up to 2v which corresponds to four times the instantaneous Power. But the mean power is just twice the Power.

Addition of Powers and Voltages is a constant source of confusion if we don't go back to basics.

Yea instantaneous adds up so the final result is like here :

Well I guess something like that. The mean can be indeed the 2x and not 4x the power. But I don't know if this is the answer though. I don't know if this information resolves my questions about the what pickup will do with this orange final signal (orange signal is the sum of all 4 signals here).

 

[Averagesupernova]

I don't know if this information resolves my questions about the what pickup will do with this orange final signal (orange signal is the sum of all 4 signals here).

The pickup is what actually is summing the other signals to get the orange one.

 

[sophiecentaur]

How the pickup will interpret it ? As I said I just did what in other websites/videos did. So I am trying to use the example to understand it because without it I am lost.

If the pickup ( and the amplifier plus scope) has a fast response (wide bandwidth) then it will produce a single varying voltage (only one trace on a scope) which will correspond to the vibrations on the strings added together at each instant. If the pickup cannot respond fast, then (as when you hear the beats between two notes) you will see a wavy trace that changes in amplitude. The fast waves will be the pickup's attempt to chase both waveforms.

 

[Xenon02]

The pickup is what actually is summing the other signals to get the orange one.

But the input must be also a sine wave / waves am I wrong ? The pickup pick the vibration and the vibration itself must be sinus wave/waves. So I though from the link and they said that the sound/vibrations are these sinuses and they add up resulting in the single wiggly signal, which the orange signal was supposed to represent.
Hence the orange signal was supposed to be the vibration signal received by the pickup. So the output that is processed by the pickup with the sinus waves signals he produces the voltage equivalent. But still the input must be sinus waves or am I wrong ? If so is there any info about it somewhere ?

You get it what I try to say here ? Like vibrations are also sinus waves if so I just made one with orange signal that has it's peaks without units because no one mentioned in the website about it.

But still interesting intel to get. But still want to confront what I read/understand/drawn with how other says, from websites as well. Because I guess my understanding isn't that incorrect but still doesn't make sense with the output max voltage value to the input values represented by my actual understanding which is the orange signal/function representing the sum of couple of the string vibrations.

 

[Xenon02]

PS.

The pickup is what actually is summing the other signals to get the orange one.

From what I understood from this is that my orange signal is not the input signal to the pickup but the output. Although what the input looks like as I mentioned in my post above.
Because in the website I understood that the sound/vibration are represented by the sum of all signals and that is what pickup receives. which made me confused, but it makes sense that vibration adds up, but it doesn't make sense when it comes to the peak values. Because it cannot exceed 1V peak.

 

[Xenon02]

@Averagesupernova

What do you think about what I've mentioned ?
I mean what I mentioned isn't wrong that much but still I wonder even if the sounds are like 300mV in peak voltage how is it that adding many voltage sinus waves with 10-300mV peaks doesn't exceed the 1V peak.

Well that and the thing I've mentioned in my posts. But still thanks for some info.

 

[Averagesupernova]

It is more of a question about magnetics. The experience I've had with this type of sensor is in tachometer pickup coils that never see anything except gear or sprocket teeth going past. Obviously slightly different than a guitar pickup. But it is the same principle. However, I did donate a speedometer sensor to a kid who made his own guitar for a science project. Didn't have all six strings but the speedo sensor was able to pickup both strings and demonstrate the principle. I never measured anything concerning the addition of several strings.
-
My guess is that the magnetic field has to change faster to get more voltage. That can translate to several different things. Not just a string that is stretched tighter. The string will have to cover the same distance faster. This takes more energy. Split a string up into several strings and the net modification of the field has to reflect any increase or decrease in mechanical power applied to the strings. Keep in mind that a poor sensor will not necessarily reflect a change like this accurately.

 

[Xenon02]

It is more of a question about magnetics. The experience I've had with this type of sensor is in tachometer pickup coils that never see anything except gear or sprocket teeth going past. Obviously slightly different than a guitar pickup. But it is the same principle. However, I did donate a speedometer sensor to a kid who made his own guitar for a science project. Didn't have all six strings but the speedo sensor was able to pickup both strings and demonstrate the principle. I never measured anything concerning the addition of several strings.
-
My guess is that the magnetic field has to change faster to get more voltage. That can translate to several different things. Not just a string that is stretched tighter. The string will have to cover the same distance faster. This takes more energy. Split a string up into several strings and the net modification of the field has to reflect any increase or decrease in mechanical power applied to the strings. Keep in mind that a poor sensor will not necessarily reflect a change like this accurately.

The faster the magnetic field changes the more voltage hmm
According to this : https://sound-au.com/articles/guitar-voltage.htm

E1 and E2 at bridge were very similar. Sometimes even E2 is smaller than E1.
At bridge the E2 has the same amplitude as chord which I guess consist of all 6 E sounds.

But I don't know if what you've said answered it. The vibration itself is also a sin wave as I understand. Many websites shows some sinuses adding up, and even in stackoverflow they've added 2 sinewaves with different frequences in result they've achieved value of "1.5" of something. I understood that this result is the input, and the output of the voltage is unknown.

How do the sounds mixs up so the amplitude doesn't skyrocket is wierd, because in examples I see they do exceed that limit, still pickup somehow works IRL, dunno why.

I accepted what you've said about power and voltage but it somehow doesn't link with the information I've found so far or have missed somewhere that part in the websites/youtube videos.

So far what I understand is the following :

- Power =/= voltage
- Maybe the signals I see are the pickup ? Although the pickup maks amplitude is 1V or 0.7V.
- Signals/sounds do sum up, and can use superpositions.

What I still don't understand is :

- What is this unit in diagrams of summed sinewaves, is it an input or and output, if an output why it exceeds 1V, if input why it exceeds value "1", hence how will the pickup respond to high pick from multiple sinuses.


For example :

So for the sake I am not taking this out of nowhere :

Looks to me like input, because the output cannot be more than 1V, so pickup somehow must work on it ? How ? I don't know, but somehow the input signal is the same as output in volts so it is magic. It somehow scales it or something, dunno.

 

[Averagesupernova]

The faster the magnetic field changes the more voltage hmm

So are you disputing my claim that a faster field change generates a higher voltage based on the difference between E1 and E2 in what you linked to? I know very little about the musical notes and scales, etc.
-
I never said a higher note will generate a higher voltage compared to a lower note. I said the vibrating string has to cover the same distance for this to be true when they are compared.

 

[Xenon02]

So are you disputing my claim that a faster field change generates a higher voltage based on the difference between E1 and E2 in what you linked to? I know very little about the musical notes and scales, etc.
-
I never said a higher note will generate a higher voltage compared to a lower note. I said the vibrating string has to cover the same distance for this to be true when they are compared.

Just trying to put on some ideas.
I just deduced that higher frequency means different sound. I also don't know much about musical notes etc. I am simply just comparing what was written here.

also trying to understand the graphs I also linked that has some Y-axis without units. Sinuses have max "1" which is of course true, but how does the input to the pickup looks like and how does the output looks like.

In my example I've shown my "theory". In which the input was the orange one (what pick up receives) and the output (voltage from pick up). The orange one has a peak of "3", and the output has the similar shape but the peak is now 0.6V and not 3V because it is somehow scaled ? Dunno, just some random guesses so far. What is input peaks where higher etc.
There is a power you've mentioned but I don't know how to link that info to the graphs.

Like I said random guesses. Maybe somebody know maybe not. But I wondered a lot because people creates these guitar effects but the voltage each sound makes and making all sounds at the same time without loosing it while the amplitude didn't change much was weird for me.
Weirder it goes when I saw this one : https://physics.stackexchange.com/questions/495511/vibration-in-a-guitar-when-playing-two-strings here they've added two sounds waves and the result was a peak pretty big, hence what will the pickup do ? "Reduce the peak" ? What rule is behind of it ?

Maybe my question is stupid and I should look at it like that but I don't know sounds like a good way to understand what pickup is receiving, and how to prepare op amp for the output voltage.

But also when reading I only see images with graphs of added signals but having high peaks, so there was only a question how pickup works with this then. or any other electric Device. If that makes sense.

 

[Baluncore]

Because it cannot exceed 1V peak.

You appear to be wrongly assuming, that all sine waves have an amplitude of ±1 volt, and that when several waves are added, they must exceed the dynamic limit of ±1 volt.

If one guitar string could produce a signal with a maximum amplitude of ±100 mV, then it would need 10 strings, played to the maximum, all at the same time, to make the maximum ±1 volt signal.

 

[Drakkith]

How do the sounds mixs up so the amplitude doesn't skyrocket is wierd, because in examples I see they do exceed that limit, still pickup somehow works IRL, dunno why.

What limit? I keep seeing you talk about some 1 volt limit. Where did you get such a number?

 

[Drakkith]

Weirder it goes when I saw this one : https://physics.stackexchange.com/questions/495511/vibration-in-a-guitar-when-playing-two-strings here they've added two sounds waves and the result was a peak pretty big, hence what will the pickup do ? "Reduce the peak" ? What rule is behind of it ?

The pickup will detect the motion of one section of the strings and output a voltage profile that is the sum of both strings. It might be similar to the 3rd graph if the pickup is located at the same place along the string that the 3rd graph is, but it doesn't have to be. If, for example, the pickup was located in the direct middle of both of the example strings, it would output a simple sine wave since there is a node at that location on the first string.

 

[Baluncore]

What limit? I keep seeing you talk about some 1 volt limit.

There was a standard for telemetry signals that were to be recorded on multichannel tape recorders, and plotted on polygraphs, that set a maximum voltage of 1 Vrms. That range would be limited to ±1.4142 volts peak.

 

[Xenon02]

You appear to be wrongly assuming, that all sine waves have an amplitude of ±1 volt, and that when several waves are added, they must exceed the dynamic limit of ±1 volt.

If one guitar string could produce a signal with a maximum amplitude of ±100 mV, then it would need 10 strings, played to the maximum, all at the same time, to make the maximum ±1 volt signal.

Perhaps, but looking at this site again :

So if 2 strings can generate 300mV like in the Bridge part, then 6 strings can exceed 1V for sure. If course they are phase shifter and have different frequency but at some point all peaks must meet somewhere and then all peaks add up which will result in high peak.

The pickup will detect the motion of one section of the strings and output a voltage profile that is the sum of both strings. It might be similar to the 3rd graph if the pickup is located at the same place along the string that the 3rd graph is, but it doesn't have to be. If, for example, the pickup was located in the direct middle of both of the example strings, it would output a simple sine wave since there is a node at that location on the first string.

simple sine wave in the middle of both strings, node at the location of first string even though the pickup is right in the middle of 2 strings ?

 

[Averagesupernova]

Well it may be stupid to someone but I wouldn't say from my perspective or yours it's a stupid question. Do you have a guitar? If so, do some experiments.

 

[Averagesupernova]

So if 2 strings can generate 300mV like in the Bridge part, then 6 strings can exceed 1V for sure.

Where is your math for this and are you assuming peak amplitude or RMS?

 

[Baluncore]

So if 2 strings can generate 300mV like in the Bridge part, then 6 strings can exceed 1V for sure.

That is irrational. If two produce 300 mV peak, then one produces 150 mV peak and six produce 900 mV peak. That is less than one volt peak, not more.

If course they are phase shifter and have different frequency but at some point all peaks must meet somewhere and then all peaks add up which will result in high peak.

This is an electric guitar. If you hit every string at once, you would complain if it did not clip and distort.