Post by antigua on Apr 16, 2022 21:26:14 GMT -5
One reason I like to do this testing is to figure out which pickups give best value for the money, and name brands like Seymour Duncan have both a name brand markup, as well as costing more because they're domestically produced. My favorite brand had been BYO, a brand that supplies various guitar parts, but I ordered some pickups from them, they said they were on back order after the fact, and they haven't responded to any of my emails for about six weeks since having placed the order. This is a change from the past, when they had communicated with me. So I went with best value #2, Tonerider, and bought a set of Alnico II Classics and the Birmingham sets. The main difference is that the former has AlNiCo 2, and the latter use AlNiCo 5, but strangely enough the Guass read about the same, around 275 over the two center screws for both sets, which is what I often measure with just AlNiCo 5 magnets.
Five point five years ago I tested the Alnico IV Classics guitarnuts2.proboards.com/thread/7805/tonerider-alnico-classics-analysis-review , also with gold covers, and the only problem I had with that set is that the covers were not Gibson-correct, they had a harder edge along the tops, which you can see in this picture i.imgur.com/enzgxa2.jpg , but I'm happy to find that these newest pickups have the more correct looking rounded edges.
The overall inductance values for both sets are what you'd expect for "vintage" PAF sets, a bridge around 5H and a neck around 4H inductance. People out there on the Internet will say all these pickups have a unique sound to them, regardless, they're all very similar in electrical terms.
I actually bought one Alnico II Classic bridge pickup and two neck pickups because this is going into a Les Paul with three pickups, and discovered something interesting. Even though all three use nickel silver as the cover material, and all are gold plated, one of the neck pickups showed greater eddy currents than the other, with a loaded resonant peak that is of a slightly lower frequency, and about 1dB less in amplitude. It's impossible to tell, but I'd guess that either the cover of the pickup with the greater eddy currents is thicker overall, or the gold plating (or the copper substrate) is a little thicker, resulting in slightly higher eddy currents. It's a certainty that the material is nickel silver, because in the case of a brass cover, the amplitude at loaded resonance would be well below -1dB, and in all cases here it is above 0dB. I put a bode plot of a gold plated brass cover below, for comparison, to see what quality looks like in graph form. The Q at 1kHz shows that the outlier neck pickup is lower than that of the bridge or second pickup by about 0.1.
I measured a low loaded resonant peak of 2.7kHz for the first neck pickup with the higher eddy currents, I'm going to call this one an outlier, because the second neck pickup conforms to the expected peak frequency given the measures inductance and capacitance. The capacitance measures around 60 to 70pF for all these humbuckers. The cable shielding of the four conductor cable is not connected in testing, but since it's four conductor, the start and finish leads are side by side for about a foot of length. A PAF usually measures about 50pF capacitance, so the other 10 to 20pF can probably be attributed to the four conductor leads being side by side. With the shielding hooked up, the capacitance increases to about 110pF, or another 40 to 50pF capacitance on account of that one foot length of shielding.
Tonerider AlNiCo II Classic AC2B Bridge
- DC Resistance: 8.200K ohms
- Q @1khz: 2.19
- Measured L: 5.082H
- Calculated C: 64pF
- Gauss: ~275G (AlNiCo 2)
Tonerider AlNiCo II Classic AC2N Neck
- DC Resistance: 7.473K ohms
- Q @1khz: 2.00
- Measured L: 4.382H
- Calculated C: 70pF
- Gauss: ~275G (AlNiCo 2)
Tonerider AlNiCo II Classic AC2N Neck #2
- DC Resistance: 7.457K ohms
- Q @1khz: 2.12
- Measured L: 4.378H
- Calculated C: 66pF
- Gauss: ~275G (AlNiCo 2)
Bridge unloaded: dV: 2.0dB f: 8.75kHz (black)
Bridge loaded (200k & 470pF): dV: 1.1dB f: 2.67kHz (blue)
Neck unloaded: dV:-0.8dB f: 9.59kHz (red)
Neck loaded (200k & 470pF): dV: 0.3dB f: 2.70kHz (green)
Neck #2 unloaded: dV:1.8dB f: 9.81kHz (red)
Neck #2 loaded (200k & 470pF): dV: 1.1dB f: 2.99kHz (green)
Bode plot of an Epiphone Pro Classic with a brass cover with gold plating for comparison:
This shows that the brass cover only reduces the treble by about 2dB in the case of a PAF style humbucker, the difference is greater as the resonant peak increases, such is the case with a Telecaster neck humbucker, or a humbucker operating in "split mode". 2dB is not a huge difference, so to a large extent, worrying about whether a PAF cover is brass or nickel silver is academic, but these pickups tend to lack treble in the first place, making it just that much harder to get brightness and clarity out of the guitar, in some situations.
This Birmingham set has a slightly higher inductance bridge and lower inductance neck than the AlNiCo II Classic set, the resonant peaks of the bridge pickups are about the same around 2.6kHz, but the Birmingham neck has about 100Hz more treble reach than the AlNiCo II Classic neck. AlNiCo 5 is generally stronger than AlNiCo 2 or AlNiCo 4, but my WT10A magnetometer shows about the same magnetic strength for all of the AlNiCo Tonerider humbuckers I've bought, around 275 gauss, where as for the AlNiCo 2 I've more often measured a gauss closer to 230 at the screw tops.
The other interesting thing, and I think I'm seeing a trend, is that gold plating seems to increase the conductivity of a cover, enough to result in higher eddy current attenuation, lowering the resonant amplitude value by 1 to 2 dBV, as seems to be the case here, between these two otherwise very similar pickups. It makes sense that the gold plating and the copper substrate underneath would increase the conductivity, but it's likely a very thin layer. Thinner plates of metal will attenuate higher frequencies than thicker ones, so it's to be expected that the a thick brass cover will have a broader attenuation, while a thin copper / gold plating will attenuate more as frequency rises.
This Birmingham set here, with the polished nickel silver cover, shows a higher Q factor than the gold plated AlNiCo II Classics.
Tonerider Birmingham AC5B Bridge
- DC Resistance: 8.335K ohms
- Q @1khz: 2.33
- Measured L: 5.342H
- Calculated C: 66pF
- Gauss: ~275G (AlNiCo 5)
Tonerider Birmingham AC5N Neck
- DC Resistance: 7.173K ohms
- Q @1khz: 2.16
- Measured L: 4.105H
- Calculated C: 61pF
- Gauss: ~275G (AlNiCo 5)
Bridge unloaded: dV: 3.8dB f: 8.27kHz (black)
Bridge loaded (200k & 470pF): dV: 1.5dB f: 2.64kHz (blue)
Neck unloaded: dV: 3.0dB f: 10.2kHz (red)
Neck loaded (200k & 470pF): dV: 1.6dB f: 3.13kHz (green)
Five point five years ago I tested the Alnico IV Classics guitarnuts2.proboards.com/thread/7805/tonerider-alnico-classics-analysis-review , also with gold covers, and the only problem I had with that set is that the covers were not Gibson-correct, they had a harder edge along the tops, which you can see in this picture i.imgur.com/enzgxa2.jpg , but I'm happy to find that these newest pickups have the more correct looking rounded edges.
The overall inductance values for both sets are what you'd expect for "vintage" PAF sets, a bridge around 5H and a neck around 4H inductance. People out there on the Internet will say all these pickups have a unique sound to them, regardless, they're all very similar in electrical terms.
I actually bought one Alnico II Classic bridge pickup and two neck pickups because this is going into a Les Paul with three pickups, and discovered something interesting. Even though all three use nickel silver as the cover material, and all are gold plated, one of the neck pickups showed greater eddy currents than the other, with a loaded resonant peak that is of a slightly lower frequency, and about 1dB less in amplitude. It's impossible to tell, but I'd guess that either the cover of the pickup with the greater eddy currents is thicker overall, or the gold plating (or the copper substrate) is a little thicker, resulting in slightly higher eddy currents. It's a certainty that the material is nickel silver, because in the case of a brass cover, the amplitude at loaded resonance would be well below -1dB, and in all cases here it is above 0dB. I put a bode plot of a gold plated brass cover below, for comparison, to see what quality looks like in graph form. The Q at 1kHz shows that the outlier neck pickup is lower than that of the bridge or second pickup by about 0.1.
I measured a low loaded resonant peak of 2.7kHz for the first neck pickup with the higher eddy currents, I'm going to call this one an outlier, because the second neck pickup conforms to the expected peak frequency given the measures inductance and capacitance. The capacitance measures around 60 to 70pF for all these humbuckers. The cable shielding of the four conductor cable is not connected in testing, but since it's four conductor, the start and finish leads are side by side for about a foot of length. A PAF usually measures about 50pF capacitance, so the other 10 to 20pF can probably be attributed to the four conductor leads being side by side. With the shielding hooked up, the capacitance increases to about 110pF, or another 40 to 50pF capacitance on account of that one foot length of shielding.
Tonerider AlNiCo II Classic AC2B Bridge
- DC Resistance: 8.200K ohms
- Q @1khz: 2.19
- Measured L: 5.082H
- Calculated C: 64pF
- Gauss: ~275G (AlNiCo 2)
Tonerider AlNiCo II Classic AC2N Neck
- DC Resistance: 7.473K ohms
- Q @1khz: 2.00
- Measured L: 4.382H
- Calculated C: 70pF
- Gauss: ~275G (AlNiCo 2)
Tonerider AlNiCo II Classic AC2N Neck #2
- DC Resistance: 7.457K ohms
- Q @1khz: 2.12
- Measured L: 4.378H
- Calculated C: 66pF
- Gauss: ~275G (AlNiCo 2)
Bridge unloaded: dV: 2.0dB f: 8.75kHz (black)
Bridge loaded (200k & 470pF): dV: 1.1dB f: 2.67kHz (blue)
Neck unloaded: dV:-0.8dB f: 9.59kHz (red)
Neck loaded (200k & 470pF): dV: 0.3dB f: 2.70kHz (green)
Neck #2 unloaded: dV:1.8dB f: 9.81kHz (red)
Neck #2 loaded (200k & 470pF): dV: 1.1dB f: 2.99kHz (green)
Bode plot of an Epiphone Pro Classic with a brass cover with gold plating for comparison:
This shows that the brass cover only reduces the treble by about 2dB in the case of a PAF style humbucker, the difference is greater as the resonant peak increases, such is the case with a Telecaster neck humbucker, or a humbucker operating in "split mode". 2dB is not a huge difference, so to a large extent, worrying about whether a PAF cover is brass or nickel silver is academic, but these pickups tend to lack treble in the first place, making it just that much harder to get brightness and clarity out of the guitar, in some situations.
This Birmingham set has a slightly higher inductance bridge and lower inductance neck than the AlNiCo II Classic set, the resonant peaks of the bridge pickups are about the same around 2.6kHz, but the Birmingham neck has about 100Hz more treble reach than the AlNiCo II Classic neck. AlNiCo 5 is generally stronger than AlNiCo 2 or AlNiCo 4, but my WT10A magnetometer shows about the same magnetic strength for all of the AlNiCo Tonerider humbuckers I've bought, around 275 gauss, where as for the AlNiCo 2 I've more often measured a gauss closer to 230 at the screw tops.
The other interesting thing, and I think I'm seeing a trend, is that gold plating seems to increase the conductivity of a cover, enough to result in higher eddy current attenuation, lowering the resonant amplitude value by 1 to 2 dBV, as seems to be the case here, between these two otherwise very similar pickups. It makes sense that the gold plating and the copper substrate underneath would increase the conductivity, but it's likely a very thin layer. Thinner plates of metal will attenuate higher frequencies than thicker ones, so it's to be expected that the a thick brass cover will have a broader attenuation, while a thin copper / gold plating will attenuate more as frequency rises.
This Birmingham set here, with the polished nickel silver cover, shows a higher Q factor than the gold plated AlNiCo II Classics.
Tonerider Birmingham AC5B Bridge
- DC Resistance: 8.335K ohms
- Q @1khz: 2.33
- Measured L: 5.342H
- Calculated C: 66pF
- Gauss: ~275G (AlNiCo 5)
Tonerider Birmingham AC5N Neck
- DC Resistance: 7.173K ohms
- Q @1khz: 2.16
- Measured L: 4.105H
- Calculated C: 61pF
- Gauss: ~275G (AlNiCo 5)
Bridge unloaded: dV: 3.8dB f: 8.27kHz (black)
Bridge loaded (200k & 470pF): dV: 1.5dB f: 2.64kHz (blue)
Neck unloaded: dV: 3.0dB f: 10.2kHz (red)
Neck loaded (200k & 470pF): dV: 1.6dB f: 3.13kHz (green)