DC Resistance and Volume
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Scott Miller
New member
Re: DC Resistance and Volume
DC resistance is a good GENERAL indicator of a pickup's output, but it is certainly not perfect. In general, the higher the DC, the higher the output of the pickup. The one thing that is not measured by DC resistance, though, is magnetism. So, while the Invader measures a DC similar to the JB---the Invader has way more magnetism and so it has much more output than the JB. This would not be measurable by metering for DC resistance.
Another case in which DC is not accurate is when you are dealing with a Stack---meaning a pickup that has two coils on top of each other. The DC readings on stacks tend to be very high compared to their actual outputs.
DC resistance is a good GENERAL indicator of a pickup's output, but it is certainly not perfect. In general, the higher the DC, the higher the output of the pickup. The one thing that is not measured by DC resistance, though, is magnetism. So, while the Invader measures a DC similar to the JB---the Invader has way more magnetism and so it has much more output than the JB. This would not be measurable by metering for DC resistance.
Another case in which DC is not accurate is when you are dealing with a Stack---meaning a pickup that has two coils on top of each other. The DC readings on stacks tend to be very high compared to their actual outputs.
Re: DC Resistance and Volume
Ok, let me show my poor knowledge of electronics with a similar question- Why can't we use genrated voltage as a better indicator of pup loudness since a pup is just a small AC genrator?
I bet the answer has to do with the Q and the amplitude of that band, but then it seems you could compare this info as well-
Kind of obvious now why I use my ear and other's review's but sure would like to understand this better-
Ok, let me show my poor knowledge of electronics with a similar question- Why can't we use genrated voltage as a better indicator of pup loudness since a pup is just a small AC genrator?
I bet the answer has to do with the Q and the amplitude of that band, but then it seems you could compare this info as well-
Kind of obvious now why I use my ear and other's review's but sure would like to understand this better-
Artie
Peaveyologist
Re: DC Resistance and Volume
You definitely could. And the fact that the way they measured it would be different than the way someone else measures it would'nt even be a problem. As long as they did the same thing with every measurement, the relative values would still be useful.
But here's why I prefer the DC resistance technique: As long as I have some experience with pickups and magnets, I can get a pretty good idea of a pups characteristics by looking at its specs. And more importantly, I can get a good idea of the identity, and characteristics of the pup, with a cheap meter. I can't do that with any other measurement type.
Edit: Just to go one step farther - if I I have the voltage output of a Duncan, a DiMarzio, and a Lawrence, I still know nothing about how they compare. Who knows how those measurements were taken. Give me the DC resistance of all three, and the magnet type, and I have a good idea how they compare. I know exactly how those measurements were taken and can duplicate them myself, at home.
zionstrat said:
You definitely could. And the fact that the way they measured it would be different than the way someone else measures it would'nt even be a problem. As long as they did the same thing with every measurement, the relative values would still be useful.
But here's why I prefer the DC resistance technique: As long as I have some experience with pickups and magnets, I can get a pretty good idea of a pups characteristics by looking at its specs. And more importantly, I can get a good idea of the identity, and characteristics of the pup, with a cheap meter. I can't do that with any other measurement type.
Edit: Just to go one step farther - if I I have the voltage output of a Duncan, a DiMarzio, and a Lawrence, I still know nothing about how they compare. Who knows how those measurements were taken. Give me the DC resistance of all three, and the magnet type, and I have a good idea how they compare. I know exactly how those measurements were taken and can duplicate them myself, at home.
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larry_emder
New member
Re: DC Resistance and Volume
What about pickups wired in parallel - They are half the dc resistance, but nowhere near half the volume (in my experience)
And when you split a humbucker, it halves the resistance, but ony gives a slight sound drop (but then again, what IS half the volume?)
Think i'm over my head on this one! lol
What about pickups wired in parallel - They are half the dc resistance, but nowhere near half the volume (in my experience)
And when you split a humbucker, it halves the resistance, but ony gives a slight sound drop (but then again, what IS half the volume?)
Think i'm over my head on this one! lol
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Artie
Peaveyologist
Re: DC Resistance and Volume
Here's how I look at that: When you wire a humbucker in parallel, you could consider it to be a variation on splitting. So, double the parallel reading, or halve the humbucker reading, (same thing), and use that measurement as your output indicator. A pup in parallel generates the same overall voltage as a single coil, but has twice the current capability. Since the extra current doesn't have much impact, the output is only slightly different. (Than if it was split.)
larry_emder said:
Here's how I look at that: When you wire a humbucker in parallel, you could consider it to be a variation on splitting. So, double the parallel reading, or halve the humbucker reading, (same thing), and use that measurement as your output indicator. A pup in parallel generates the same overall voltage as a single coil, but has twice the current capability. Since the extra current doesn't have much impact, the output is only slightly different. (Than if it was split.)
larry_emder
New member
Re: DC Resistance and Volume
Ahh, i getcha.
Ahh, i getcha.
fab.regnaut
New member
Re: DC Resistance and Volume
One thing you should know is with a high dc resistance the signal distort the preamp more , you have more distortion BUT less attack and then less PUNCH so sometime medium dc p-u are LOUDER than high ones .
For example hit a chord with a lot of distortion and hit a chord with a clean signal : the second one is harder on the ears like a BANG ( if the ouput level is the same ).
One thing you should know is with a high dc resistance the signal distort the preamp more , you have more distortion BUT less attack and then less PUNCH so sometime medium dc p-u are LOUDER than high ones .
For example hit a chord with a lot of distortion and hit a chord with a clean signal : the second one is harder on the ears like a BANG ( if the ouput level is the same ).
Scott Miller
New member
Re: DC Resistance and Volume
Artie is correct about measuring the voltage (milli-volts in this case). To get a reading in millivolts, there must be an input signal going into the pickup (someone strumming the guitar). The harder you strum, the higher the millivolt reading will be. So it tends to be a measurement of the player, and not the pickup. What you would have to do is measure all of the pickups in the catalog on the same guitar, with a mechanical strumming arm to ensure that all of the strums were equal. And even if you did THAT, the millivolt readings you ended up with would not be useable in terms of comparing Duncans with Dimarzios unless you measured all of them with the same set-up. DC resistance is what it is no matter who made the pickup.
Artie is correct about measuring the voltage (milli-volts in this case). To get a reading in millivolts, there must be an input signal going into the pickup (someone strumming the guitar). The harder you strum, the higher the millivolt reading will be. So it tends to be a measurement of the player, and not the pickup. What you would have to do is measure all of the pickups in the catalog on the same guitar, with a mechanical strumming arm to ensure that all of the strums were equal. And even if you did THAT, the millivolt readings you ended up with would not be useable in terms of comparing Duncans with Dimarzios unless you measured all of them with the same set-up. DC resistance is what it is no matter who made the pickup.
Re: DC Resistance and Volume
For matched coil humbucker
series = K resistance with V voltage (I current)
parallel = K/4 resistance with ~V/2 voltage (I current?)
split = K/2 resistance with ~V/2 voltage (I/2 current?)
So, parallel and split have the same sort of volume drop (voltage)
but parallel goes to a lower resistance, meaning it will have more
treble than the split pup. With a vintage HB, I find parallel in
bridge position, to be unbearable.
[Vintage Rails are a parallel wiring of something pretty close to Cool Rails]
[Is Humbucker from Hell just a parallel wiring of an otherwise hefty pup?]
larry_emder said:
For matched coil humbucker
series = K resistance with V voltage (I current)
parallel = K/4 resistance with ~V/2 voltage (I current?)
split = K/2 resistance with ~V/2 voltage (I/2 current?)
So, parallel and split have the same sort of volume drop (voltage)
but parallel goes to a lower resistance, meaning it will have more
treble than the split pup. With a vintage HB, I find parallel in
bridge position, to be unbearable.
[Vintage Rails are a parallel wiring of something pretty close to Cool Rails]
[Is Humbucker from Hell just a parallel wiring of an otherwise hefty pup?]
Artie
Peaveyologist
Re: DC Resistance and Volume
Measuring henries, instead of resistance, is just substituting one static measurement for another. And, you're back to needing expensive test equipment to do it. Take a look at this pdf document on inductance measurement. Short quote: (emphasis mine)
I find it funny that a certain pup maker casts aspersions at Duncans listing of DC measurement, (claiming how worthless it is), then lists henries instead.
Note that they don't list the frequency or equipment used to make the test. And once again, you can't pull an unidentified pup out of a drawer, throw a $3 meter on it, and have a fair idea of what it is.
Artie
ErikH said:
Measuring henries, instead of resistance, is just substituting one static measurement for another. And, you're back to needing expensive test equipment to do it. Take a look at this pdf document on inductance measurement. Short quote: (emphasis mine)
I find it funny that a certain pup maker casts aspersions at Duncans listing of DC measurement, (claiming how worthless it is), then lists henries instead.
Note that they don't list the frequency or equipment used to make the test. And once again, you can't pull an unidentified pup out of a drawer, throw a $3 meter on it, and have a fair idea of what it is.
Artie
Re: DC Resistance and Volume
Ok, I'm trying to learn so is the is possible?
Suspend a sustainer a certan distance from the strings- Maybe 2 different distances from bridge?
Pump X voltage through the sustainer
Measure pup's microvolts
I doubt you could do it as a % of the input, but wouldn't this be rather repeatable?
Ok, I'm trying to learn so is the is possible?
Suspend a sustainer a certan distance from the strings- Maybe 2 different distances from bridge?
Pump X voltage through the sustainer
Measure pup's microvolts
I doubt you could do it as a % of the input, but wouldn't this be rather repeatable?
Zhangliqun
Questionologist
Re: DC Resistance and Volume
Evan explained in another thread that voltage as a measure is worthless because it would depend so much on the individual player and how hard or soft he/she hits the strings, what kind of pick, where on the string they hit, etc.
The best way to look at it is:
All other things being equal (same magnet, same size coil, same pickup type, e.g., humbucker/P90/single coil, same polepiece type, etc.), DC resistance is a pretty accurate guide on output.
From there you can learn to factor in magnet type, polepiece type (standard vs. allen screws vs. Invader screws), etc. And from there, you just put an asterisk next to stacked/noiseless "single" coils to remind you that stacks are just very different animals and the DC resistance rule of thumb just doesn't apply as has already been pointed out.
There is also a far lesser known factor, the PHYSICAL WIDTH of the coil. A wider coil will see the longer wavelengths on the string and give you much fuller/clearer bass response. The most extreme example of this is a humbucker vs. a single coil. Two coils will see the long bass wavelengths very clearly, whereas just one will see only a portions of them. Any 8k/vintage-style humbucker will have much better bass response than even a 10-11k single coil because it sees about twice as long a segment of the string as the single coil does. The P90 is something of an exception but again, this is because a P90 coil is much wider than a Strat-style single.
This physical width thing is one of the reasons I am seriously considering modifying my Strat to take a Tele bridge pu. The Tele bridge bobbin is a good deal wider than a Strat bobbin so you can get a wider coil on it. (I made a Tele bridge for kjrocks last week that I almost cried when I finally forced myslef to let go with my hand and let it drop in the mailbox to him. GOTTA have that sound in my Strat now...)
Evan explained in another thread that voltage as a measure is worthless because it would depend so much on the individual player and how hard or soft he/she hits the strings, what kind of pick, where on the string they hit, etc.
The best way to look at it is:
All other things being equal (same magnet, same size coil, same pickup type, e.g., humbucker/P90/single coil, same polepiece type, etc.), DC resistance is a pretty accurate guide on output.
From there you can learn to factor in magnet type, polepiece type (standard vs. allen screws vs. Invader screws), etc. And from there, you just put an asterisk next to stacked/noiseless "single" coils to remind you that stacks are just very different animals and the DC resistance rule of thumb just doesn't apply as has already been pointed out.
There is also a far lesser known factor, the PHYSICAL WIDTH of the coil. A wider coil will see the longer wavelengths on the string and give you much fuller/clearer bass response. The most extreme example of this is a humbucker vs. a single coil. Two coils will see the long bass wavelengths very clearly, whereas just one will see only a portions of them. Any 8k/vintage-style humbucker will have much better bass response than even a 10-11k single coil because it sees about twice as long a segment of the string as the single coil does. The P90 is something of an exception but again, this is because a P90 coil is much wider than a Strat-style single.
This physical width thing is one of the reasons I am seriously considering modifying my Strat to take a Tele bridge pu. The Tele bridge bobbin is a good deal wider than a Strat bobbin so you can get a wider coil on it. (I made a Tele bridge for kjrocks last week that I almost cried when I finally forced myslef to let go with my hand and let it drop in the mailbox to him. GOTTA have that sound in my Strat now...)
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Artie
Peaveyologist
Re: DC Resistance and Volume
Interesting comments Zhang. Just to add to that - some of the experiments I've done at the cal lab with plugging a guitar into an o'scope seem to indicate that a string generates it's greatest voltage as it moves to and from the pickup rather than across its surface. If you look at a string closely as it vibrates, you can see that the plane of vibration rotates in a circle. If you look at the output on a scope, you can see that every other cycle appears to be missing. Thats because of the string cycling between fore & aft motion and side-to-side motion.
I think.
Interesting comments Zhang. Just to add to that - some of the experiments I've done at the cal lab with plugging a guitar into an o'scope seem to indicate that a string generates it's greatest voltage as it moves to and from the pickup rather than across its surface. If you look at a string closely as it vibrates, you can see that the plane of vibration rotates in a circle. If you look at the output on a scope, you can see that every other cycle appears to be missing. Thats because of the string cycling between fore & aft motion and side-to-side motion.
I think.
Zhangliqun
Questionologist
Re: DC Resistance and Volume
Makes sense, on the side-to-side motion it's moving the magnetic field in a motion parallel to the coil, whereas up and down moves the magnetic field perpendicular to the coil. Maybe it's a with-the-grain vs. against-the-grain thing with the against causing a greater "shock" and therefore current in the coil?
ArtieToo said:Interesting comments Zhang. Just to add to that - some of the experiments I've done at the cal lab with plugging a guitar into an o'scope seem to indicate that a string generates it's greatest voltage as it moves to and from the pickup rather than across its surface. If you look at a string closely as it vibrates, you can see that the plane of vibration rotates in a circle. If you look at the output on a scope, you can see that every other cycle appears to be missing. Thats because of the string cycling between fore & aft motion and side-to-side motion.
I think.
Makes sense, on the side-to-side motion it's moving the magnetic field in a motion parallel to the coil, whereas up and down moves the magnetic field perpendicular to the coil. Maybe it's a with-the-grain vs. against-the-grain thing with the against causing a greater "shock" and therefore current in the coil?
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