Post by antigua on Sept 25, 2016 19:08:44 GMT -5
www.seymourduncan.com/pickup/antiquity-texas-hot-strat-set
This is Seymour Duncan's distressed AlNiCo 2 Strat set. They're price in the boutique range. Even the edges of the bobbins are warn down, making it look as though the pickups themselves were subject to the abuse of time, despite sitting within a protective plastic housing. They are impressively dirty.
I had this set in two different Strats, but they always seemed too dark, so they eventually came out. Based on these measurements, I've come to the conclusion that if a Strat doesn't achieve a loaded peak of at least 3.75. I'd say the Lollar Blackface set is where I draw the line; any darker than that and I'm not a fan. The neck and middle Antiquity I's peak at about 3.6kHz, and the neck is much lower at 3.1kHz
These pickups also feature AlNiCo 2 with about half the Gauss of AlNiCo 5, so you have a dark resonant peak combined with the hard-to-explain darker tone associated with weaker magnetism, making for a pickup that I would not describe as being especially Stratty.
Antiquity I Texas Hot Bridge SN 13129154
DC Resistance: 10.31K
Inductance: 3.858 H
Resonant Peak: 8.61 kHz
Calculated C: 69pF (89-20)
Coil width: 0.60"
Antiquity I Texas Hot Middle SN 14010381
DC Resistance: 6.58K
Inductance: 2.911 H
Resonant Peak: 8.22 kHz
Calculated C: 109pF (129-20)
Coil width: 0.57"
Antiquity I Texas Hot SN 13129840
DC Resistance: 6.58K
Inductance: 2.854 H
Resonant Peak 8.52 kHz
Calculated C: 102pF (122-20)
Coil width: 0.575"
Guass strength: Between 500 and 600, with two pole pieces reading just over 700
Bode plot, featuring both loaded and unloaded plots for all three pickups:
Some interesting aspects:
The hot bridge has a resonant peak similar to the not hot neck and middle, all near 8.5kHz, but under load, the resonant peak of the hot bridge becomes a lot lower, 3.1kHz to 3.6kHz. The math says the reason for this is a much lower parasitic capacitance in the hot bridge, which uses finer 43AWG or 44AWG wire, while the neck and middle use more common 42AWG. The low capacitance of the bridge allows it to stand "neck and neck" with the neck and middle pickups, and in fact shows a higher peak than the middle pickup, but once you add a theoretical guitar cable to the equation, the high capacitance of the guitar cable "swamps" all the pickups with a lot more parallel capacitance than any of the pickups naturally has, at which point the bridge's 3.858 henry inductance causes it's peak to drop much lower, to 3.1kHz.
I'm all but certain that finer gauge wire used in the hot bridge results in that lower parasitic capacitance. I still have a lot of 43 or 44 AWG pickups to test yet, so I'm waiting to see if this trend continues, unspoiled.
Low Q due to AlNiCo 2. As with the Tonerider Surfari's which feature similar AlNiCo 3 poles, there is a Q in the area of 1.5 for the neck and middle Antiquity I Texas Hots, while a loaded Q factor of 1.8 has been more typical with AlNiCo 5 pickups.
The bridge pickup has an exceptionally low loaded Q of 1.2, that could owe to the 10.3K DC resistance. I haven't measured too many super-high output AlNiCo single coils yet, so I might be able to say more about it once I have more data points. With a more realistic load of 125k, the bridge's -3dB Q factor is non existent, and shows up as a barely visible bump in the bode plot, which goes to show that lossy pickups don't have resonant peaks so much as they have "resonant knees".
Setup details:
Bode plots are made with a Velleman PCSGU250 and the supplied probes in 10x mode, with the function generator feeding a driver coil of 0.48mH, placed on top of the pickup and driven with 2Vpp. The pickup is connected to an integrator circuit, designed by Ken Willmottkenwillmott.com/blog/, with a Velleman 10x probe, and fed back into the Velleman PCSGU250. I measured the probes' capacitance at 20pF, so that amount is subtracted from the capacitance calculation. The "loaded" tests have exactly 470k ohms and 200pF capacitance across the pickup.
The inductance and Q measurements are made with an Extech 380193 in "SER" series mode, and the mean value between the 1kHz and 120Hz modes is recorded. The capacitance value is derived from the inductance and measured resonant peak.
Magnets are tested with a Spin Doctor ERgravitastech.weebly.com/spin-doctor-er.html