Hi there, I'm trying to figure out how to make a more versitile, yet still great sounding strat pickup for John Mayer tones. I really like the sound of underwound JM Big Dipper pickups (are those the same ones on Black1?), but I also love the sound of his '63/'64 sunburst strat (and the prs silver sky which is mostly based on the '63/'64).
Big Dippers (to the best of my knowledge):
- Alnico 5?
- Neck = 5.75k Ohm (7300-7600 turns?)
- Middle = 5.88k Ohm (7450-7700 turns?)
- Bridge = 6.23k Ohm (7900-8300 turns?)
Silver Sky:
- Alnico 5?
- All positions 6.4k (8300 turns?)
'63/'64 (from radioshop and klein):
- Alnico 5
- Neck = 6-6.1k Ohm (7300-7600 turns?)
- Middle = 6-6.2k Ohm (7800-8200 turns?)
- Bridge = 6-6.2k Ohm (7800-8200 turns?)
Suppose you wound pickups with 3 taps (for example a 6.4k pup with taps at 6.23k and at 6.1k), and wired all 3 pickups up to a 3p3t switch. This would essentially allow you to switch between the 3 pickups sets, meaning 3 guitars in one basically. How would this sound, would the unused coil segments (that have no current flowing through them) affect the sound of the pickup? if so how much, would the difference between this set and the 3 normal sets realistically be noticable or not?
Also: I googled dc resistance per turn for a strat and that is what my turn calculations are based off. Am I right or I am off?
Thanks for reading
Big Dippers (to the best of my knowledge):
- Alnico 5?
- Neck = 5.75k Ohm (7300-7600 turns?)
- Middle = 5.88k Ohm (7450-7700 turns?)
- Bridge = 6.23k Ohm (7900-8300 turns?)
Silver Sky:
- Alnico 5?
- All positions 6.4k (8300 turns?)
'63/'64 (from radioshop and klein):
- Alnico 5
- Neck = 6-6.1k Ohm (7300-7600 turns?)
- Middle = 6-6.2k Ohm (7800-8200 turns?)
- Bridge = 6-6.2k Ohm (7800-8200 turns?)
Suppose you wound pickups with 3 taps (for example a 6.4k pup with taps at 6.23k and at 6.1k), and wired all 3 pickups up to a 3p3t switch. This would essentially allow you to switch between the 3 pickups sets, meaning 3 guitars in one basically. How would this sound, would the unused coil segments (that have no current flowing through them) affect the sound of the pickup? if so how much, would the difference between this set and the 3 normal sets realistically be noticable or not?
Also: I googled dc resistance per turn for a strat and that is what my turn calculations are based off. Am I right or I am off?
Thanks for reading
Hi russc, no they are specifically chosen for a specific tone he had in mind (except the vintage one). bucks bunny, I agree with the "tone is in the hands part" but the different pickups still interact differently with pedals and amps, just like how an overwound pickup is going to push drive and fuzz pedals and amps more than an underwound one, and will have more mids.
My logic tells me that if you tap a coil, the unused part of the coil has no current flowing through it since it's no longer grounded (loop is open), so it shouldn't have any effect on the part of the coil that you use, right? what about stray currents in the unused part generated by the strings and magnets, that should no be possible, right (since it's not grounded)? And what about the presence of the unused part of the coil, meaning metal in close proximity to the pickup, would that affect the capacitance or inductance of the pickup?
When using all of the pickup windings, there should be no difference because there is no extra wire/coils. My main concern is when you tap it.
My logic tells me that if you tap a coil, the unused part of the coil has no current flowing through it since it's no longer grounded (loop is open), so it shouldn't have any effect on the part of the coil that you use, right? what about stray currents in the unused part generated by the strings and magnets, that should no be possible, right (since it's not grounded)? And what about the presence of the unused part of the coil, meaning metal in close proximity to the pickup, would that affect the capacitance or inductance of the pickup?
When using all of the pickup windings, there should be no difference because there is no extra wire/coils. My main concern is when you tap it.
Pickups have a resonance (basically a boost at that frequency range) that's based on the inductance and the self-capacitance distributed throughout the winding. It's around 5kHz but the more winding, the more inductance and self-capacitance and the lower the resonant frequency.
So a pickup with taps is likely to sound like a pickup with the whole winding, with the taps just giving a slightly smaller signal level. It's basically an autotransformer. So yes, the unused coil segments do affect the sound, and it'll sound like the higher impedance pickup regardless.
Perhaps if the windings were separate, each one coming out to two wires, the smaller disconnected windings wouldn't have much effect. You'd connect them in series to make the higher impedance pickup (taking several poles of switching), observing proper polarity, of course. Then again, "improper" polarity will have a different effect in the sound, not the one you're looking for, but still perhaps desirable.
There's also the loading of the volume and tone controls (250k on a Strat), and the cable capacitance can also lower the resonance with the volume control at full on. I've heard of wiring the pickup switch straight to the output jack, bypassing volume and tone. There's also the idea of having an active buffer for each pickup, eliminating the loading effects of volume, tone and cable capacitance.
This thread belongs under "Instruments and Amps." If you ask a Mod, they can move it for you.
The self-resonance is certainly audible, and measurable as well. I did these measurements with totally unloaded single coil PUs an found peaks ranging upto 10kHz (Tesla PUs). But these peaks shift considerably with the wiring: The pots dampen the peak of the amplitude. The cable with typically 100pF/m shifts it towards lower frequencies. You easily perceive the sound difference between 1m and 5m guitar cable. So, if you want to reproduce exactly the guitar sound of JM, you have to reproduce the hole wiring including the same cable and input impedance of the amp.
Plus the sound of the passive wiring varies with volume pot position.
All these uncertancies convinced me to insert a buffer amp into my strat, achieving my sound independent of pot position and cable length.
just my 2c
Plus the sound of the passive wiring varies with volume pot position.
All these uncertancies convinced me to insert a buffer amp into my strat, achieving my sound independent of pot position and cable length.
just my 2c
This will short the entire PU. The windings on the same core is just like a transformer. The shorted part will reflect the load into the other windings.
The resonance from the self-capacitance tends to produce a dip in the frequency response, and 5 kHz is above the frequency range reproduced by a typical guitar speaker...
Meantime, the resonance caused by the pickup inductance and the capacitance of the (guitar cable + amplifier input) - which is much, much bigger than the distributed capacitance in the pickup winding - falls within the guitar frequency range, and seems to be the thing we notice as a change in sound.
A bit silly, as people pay hundreds of bucks for new pickups, often without realizing that the length of guitar cable you use has a considerable effect on the guitar sound, and is a lot cheaper to fiddle with...or they buy super-expensive cables that claim to have all sorts of magic mojo, when an ordinary - but shorter - guitar cable would most likely have the same result.
I don't think this is correct. With part of the coil open-circuit and unloaded, no current flows in that part of the winding, it creates no magnetic field, and cannot influence the electrical signal from the pickup.
There are lots of humbucker pickups on the market with "split coils", i.e. all four winding ends are brought out of the pickup, allowing people to wire the two coils in series, in parallel, or to use just one coil (with the other coil still electrically attached, but the far end of the second winding open-circuit). Each of those options produces a different sound.
Since it seems the distributed self-capacitance of the pickup isn't actually audibly significant, I don't see how, with no current flow in the unused segments, and the far end open-circuit, so it contributes no voltage.
I've heard of guitarists who prefer this, but it produces a rather inflexible result - the guitarist cannot easily adjust his sound while playing a song.
Really good electric guitarists use their volume and tone controls while playing a piece, not only to produce changes in dynamics and tone, but also to vary the amount of overdrive produced by the guitar amplifier, varying the timbre in the process.
So a more musical solution is to set the amplifier to be brighter than you want with the guitar tone knob all the way up; now the guitarist can turn down the guitar's tone knob as needed during a piece to vary the guitar tone.
In the same way, set the amplifier to be louder than you want with the guitar's volume knob all the way up, then start playing with the knob turned down a bit; this lets you turn up or down during a piece, to vary dynamics and timbre.
Here's Joe Bonamassa demonstrating the almost incredible range of sounds he can get out of one guitar, one amp, and no pedals, simply by using his guitar's onboard tone and volume knobs: YouTube
And here is Zakk Wylde playing his beautiful instrumental piece "Farewell Ballad". Watch how many times he drops his right hand to the guitar's volume knob, repeatedly making almost imperceptible changes, steadily increasing the amount of distortion from his amplifier in the process, and using this (along with increased playing intensity and more and more faster, shorter notes) to ramp up the emotional intensity of the piece as it progresses: YouTube
Like most people coming from a Hi-Fi audio electronics background, this idea occurred to me when I first began to play electric guitar, and I built a JFET preamp of my own design into the home-made electric guitar I was playing at the time. It did indeed make it possible to use a long guitar cable without a change in tone.
But what I eventually realized, years later, was that I could in fact get the range of sounds I wanted out of an unbuffered guitar pickup and perfectly ordinary guitar cable. Meantime, the buffer introduced extra problems - it needed a battery or special power supply and guitar cable (phantom power), it reduced compatibility with the vast majority of existing guitar amplifiers (which were designed to work best with passive pickups and normal-length guitar cables), and so on. And so I found myself going back to the primitive but effective original plan that created most of the guitar sounds we grew up to love: a passive guitar pickup, a length of guitar cable, and a tube amp.
There's no doubt that there is a lot of conservatism among guitar players, but some of that conservatism has good reason for existing: there are some things it's hard to improve on, particularly mature products that have evolved over a considerable period of time.
The electric guitar has been around for nearly 90 years now. George Beauchamp created the first true electromagnetic guitar pickup, and then the first successful production guitars to use it, the Ro-Pat-In "Frying-Pan" Hawaiian guitar, and the more conventional Ro-Pat-In Electro Spanish guitar, in 1931 or 1932.
Ninety years is a long time, long enough for the technology to mature more or less to perfection; like most mature technologies, there tend to be fewer and fewer worthwhile improvements left to discover. People have tried everything from carbon-fibre necks to computerized "robot" tuning machines, but in the end, most of those have proven to be evolutionary dead-ends.
Now if only somebody could make single-coil pickup hum go away, without losing any of the brightness of a good traditional single-coil pickup! Sadly, an electronic signal buffer in the guitar won't do that!
-Gnobuddy
I don't think this is necessary, or will have any audible effect, since stray capacitance inside the pickup winding is not actually audible in the guitar's sound.
Look at the switching schemes used with the millions of coil-tapped humbucker pickups already out there - how often do you see DPDT switching used to go from two coils in series to just one single coil?
-Gnobuddy
It may be worth mentioning that I have two humbucking pickups, both of which have very nearly the same DC winding resistance, but which sound extremely different in the same guitar. One is dull and lifeless compared to the other.
The dull-sounding one has a metal cover over the coil, and the manufacturer made the tragic mistake of using metal that's too thick, and too conductive. The dull sound is probably because of excessive eddy-current losses in this cover.
For completeness, I should add that I can't tell what wire gauge is used internally in either pickup. There is always the possibility that they use different wire gauges and different numbers of winds that just happened to work out to nearly the same DC resistance.
But my bet is that this is not the case - the dull-sounding one came with a guitar made in South Korea, and I think the manufacturer made the attempt to replicate the original Gibson humbucker specs, but didn't understand that this also applied to the material (resistivity) and thickness of the metal housing around the pickup.
-Gnobuddy
The dull-sounding one has a metal cover over the coil, and the manufacturer made the tragic mistake of using metal that's too thick, and too conductive. The dull sound is probably because of excessive eddy-current losses in this cover.
For completeness, I should add that I can't tell what wire gauge is used internally in either pickup. There is always the possibility that they use different wire gauges and different numbers of winds that just happened to work out to nearly the same DC resistance.
But my bet is that this is not the case - the dull-sounding one came with a guitar made in South Korea, and I think the manufacturer made the attempt to replicate the original Gibson humbucker specs, but didn't understand that this also applied to the material (resistivity) and thickness of the metal housing around the pickup.
-Gnobuddy
The resonance from the self-capacitance tends to produce a dip in the frequency response, and 5 kHz is above the frequency range reproduced by a typical guitar speaker...
Meantime, the resonance caused by the pickup inductance and the capacitance of the (guitar cable + amplifier input) - which is much, much bigger than the distributed capacitance in the pickup winding - falls within the guitar frequency range, and seems to be the thing we notice as a change in sound.
A bit silly, as people pay hundreds of bucks for new pickups, often without realizing that the length of guitar cable you use has a considerable effect on the guitar sound, and is a lot cheaper to fiddle with...or they buy super-expensive cables that claim to have all sorts of magic mojo, when an ordinary - but shorter - guitar cable would most likely have the same result.
I don't think this is correct. With part of the coil open-circuit and unloaded, no current flows in that part of the winding, it creates no magnetic field, and cannot influence the electrical signal from the pickup.
There are lots of humbucker pickups on the market with "split coils", i.e. all four winding ends are brought out of the pickup, allowing people to wire the two coils in series, in parallel, or to use just one coil (with the other coil still electrically attached, but the far end of the second winding open-circuit). Each of those options produces a different sound.
Since it seems the distributed self-capacitance of the pickup isn't actually audibly significant, I don't see how, with no current flow in the unused segments, and the far end open-circuit, so it contributes no voltage.
I've heard of guitarists who prefer this, but it produces a rather inflexible result - the guitarist cannot easily adjust his sound while playing a song.
Really good electric guitarists use their volume and tone controls while playing a piece, not only to produce changes in dynamics and tone, but also to vary the amount of overdrive produced by the guitar amplifier, varying the timbre in the process.
So a more musical solution is to set the amplifier to be brighter than you want with the guitar tone knob all the way up; now the guitarist can turn down the guitar's tone knob as needed during a piece to vary the guitar tone.
In the same way, set the amplifier to be louder than you want with the guitar's volume knob all the way up, then start playing with the knob turned down a bit; this lets you turn up or down during a piece, to vary dynamics and timbre.
Here's Joe Bonamassa demonstrating the almost incredible range of sounds he can get out of one guitar, one amp, and no pedals, simply by using his guitar's onboard tone and volume knobs: YouTube
And here is Zakk Wylde playing his beautiful instrumental piece "Farewell Ballad". Watch how many times he drops his right hand to the guitar's volume knob, repeatedly making almost imperceptible changes, steadily increasing the amount of distortion from his amplifier in the process, and using this (along with increased playing intensity and more and more faster, shorter notes) to ramp up the emotional intensity of the piece as it progresses: YouTube
Like most people coming from a Hi-Fi audio electronics background, this idea occurred to me when I first began to play electric guitar, and I built a JFET preamp of my own design into the home-made electric guitar I was playing at the time. It did indeed make it possible to use a long guitar cable without a change in tone.
But what I eventually realized, years later, was that I could in fact get the range of sounds I wanted out of an unbuffered guitar pickup and perfectly ordinary guitar cable. Meantime, the buffer introduced extra problems - it needed a battery or special power supply and guitar cable (phantom power), it reduced compatibility with the vast majority of existing guitar amplifiers (which were designed to work best with passive pickups and normal-length guitar cables), and so on. And so I found myself going back to the primitive but effective original plan that created most of the guitar sounds we grew up to love: a passive guitar pickup, a length of guitar cable, and a tube amp.
There's no doubt that there is a lot of conservatism among guitar players, but some of that conservatism has good reason for existing: there are some things it's hard to improve on, particularly mature products that have evolved over a considerable period of time.
The electric guitar has been around for nearly 90 years now. George Beauchamp created the first true electromagnetic guitar pickup, and then the first successful production guitars to use it, the Ro-Pat-In "Frying-Pan" Hawaiian guitar, and the more conventional Ro-Pat-In Electro Spanish guitar, in 1931 or 1932.
Ninety years is a long time, long enough for the technology to mature more or less to perfection; like most mature technologies, there tend to be fewer and fewer worthwhile improvements left to discover. People have tried everything from carbon-fibre necks to computerized "robot" tuning machines, but in the end, most of those have proven to be evolutionary dead-ends.
Now if only somebody could make single-coil pickup hum go away, without losing any of the brightness of a good traditional single-coil pickup! Sadly, an electronic signal buffer in the guitar won't do that!
-Gnobuddy
Wow thanks, this is the mother of all respones
Gnobuddy I appreciate that you broke things down to an actually quatifyable level. This has pretty much cleared up all of the questions I had.
Thanks all.
Here's a recent thread on the capacitance when you are making tapped coils.
Different gauge wire on same pickup
Different gauge wire on same pickup
Glad to help.
I was the only schoolkid I know who got in trouble in English Composition class for writing too many words.
-Gnobuddy
is it possible to learn this power?
An unused coil in a magnetic circuit can and does influence the operation of ALL other coils in the same magnetic circuit. This is the required mechanism for proper action of things like RF duplexers in a cell tower. There is one driven coil, and one output coil with several parasitic coils in between to define the overall frequency response of the entire "cavity."
It is also the principle that Tesla exploited so well with his famous coils. The wire in the secondary and its parasitic capacitance form a resonant circuit, acting much like the wire loop antenna in an old AM radio, where the "primary coil" can be miles away. It will absorb energy at its resonant frequency, some of which will be dissipated in its winding resistance, magnetic, and other INTERNAL losses. There will be a voltage at the "loose end" but no path for EXTERNAL current flow. As with Mr. Tesla's coils and an unconnected secondary on an overdriven OPT, drive it hard enough and there WILL be some current flow, often destructive in nature.
These effects may not be audible in a guitar pickup, especially when loaded with pots and a cable. They are probably measurable on a bare unloaded pickup.
They are often audible and measurable when attempting to drive part of a vacuum tube OPT's primary while leaving an unterminated end floating. There is always a notch in the response of most OPT's from the leakage inductance resonating with the winding capacitance. Driving some OPT's like the big 5K ohm Hammond 1628SEA that I an currently using from the UL tap while leaving the plate tap open produces a double notch. I get better results driving the entire winding and hanging the 8 ohm load on the 16 ohm tap to get an impedance in the 2000 to 2500 ohm range.
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