下面文字出自 Guitar Player 雜誌 1994 年四月號 "In Search Of The Vintage Grail" Pickup designers speak out 一文： ======================================== LINDY FRALIN: I'm not an engineer, and I don't even know what half the electrical terms mean. My pickups are just copies of pre-CBS Fenders. I don't know if Leo Fender hit on some of these things by accident or he was that good. Maybe he had everything planned. I've peeled pre-CBS Fender Strat pickups and noticed how the windings were randomly layered. That's why some old Fenders are dark and loud and others are bright and jangly. The same goes for patent-applied-for Gibsons. The hand layering with a different amount of turns throughout the coil is what I believe is different about those old pickups. When I wind coils there might be a section with 100 turns of wire per layer and another with 50 turns. This is how the old ones were made, and that's all we do. I make one model of Strat pickup, and we'll make any variation that somebody wants. You can have it left-handed, magnets staggered out the bottom, any of the three reverse-wound, or really hot. By using thinner wire, we can get a thousand more turns for a hotter output. More turns also equals more mids and dirt, with less highs and bottom. Leo Fender knew exactly how many turns he could get away without humping up the midrange. If you add any extra, you start to get a very thick and dirty-sounding pickup which can be cool for the bridge position. I just wind something and go home and listen to it. It's a very slow, time-consuming thing. Instead of trying to make a line of, say, six different Strat pickups just to please everybody, I make one kind and vary the power and the brightness depending on what a person wants. I test my pickups clean. If they sound good clean through my favorite amp, then I know they'll sound good distorted. I have a brown Fender Vibroverb reissue, a Tony Bruno custom amp, a blackface Deluxe Reverb, a Super Reverb, and a Princeton Reverb. I usually test a pickup through at least a couple of those amps. My idea of classic Strat tone is to have the wound strings nice and bright and the plain strings mellow with a nice thickness. It's a very fine line and you have to get right on it, or you end up with too much treble on the high strings and dull-sounding wound strings. That's why we have to keep listening to pickups and reject them now and then. It's not always possible to cure a bad-sounding guitar with pickups. I discourage selling pickups to people with a Strat that they've tried many sets in and it always sounds like shit. If it's early '70s and heavy as lead, they should sell that guitar because my pickups are going to do the same thing. Other than that, unless it's way too heavy, way too light, or the neck is warped, there isn't such a thing as a bad guitar. The Strat is so unique. It's practically a hollowbody because of all the wood missing between the bridge and the neck joint. It lets the characteristics of the wood come through almost as much as a carved top. I sold a set of pickups to a customer recently, and he hated them. I couldn't figure out what was wrong until he finally told me his guitar had a solid rosewood body, he might as well have made it out of marble.
轉貼： http://www.flyingvintage.com/gcmag/PAF.html =============== October 2001 Issue - A Few Secrets About Gibson PAF Pickups, with Lindy Fralin: Part 1 By Larry Meiners The PAF legend was born during the recording sessions of amazing songs by Jimmy Page and his PAF equipped 1959 Les Paul, by the blues based tones of Mike Bloomfield and Eric Clapton and their Les Paul guitars, by the blazing guitar leads of Eddie Van Halen and his rewound PAF in his parts guitar, by the blues-based rock of Billy Gibbons of ZZ Top and his Pearly Gates flametop with PAFs, as well as other music artists. The PAF story has a life of it's own. Some of the stories about PAFs are true, some myth and some created from outright poor conclusions. Not all original PAFs are made the same. Here's part 1 of the PAF story: The History By the mid-1950s, Gibson wanted to counter the latest electric guitars introduced by competitors and especially those by Fender. Leo Fender had built a company from nothing in the mid-1940s to a substantial factor in the solid-body guitar market. Gibson believed they could beat Fender and other rivals for market share by developing a low-noise pickup. Players loved the sound of Gibson's P-90 and Fender's single-coil pickups, but they also put up with the 60-cycle hum (noise) inherent in their respective designs. Gibson's management assigned this important task to one of their engineers, the late Seth Lover. Seth's subsequent design and patent changed guitar playing and music recording history. Let's leave the heavy technical discussion for another article and understand the basic design: Seth connected two single coil pickups in series. However, he connected the coils out-of-phase electrically and magnetically. Thus, the signal is passes through the pickup minus much of the noise or hum. That is how the pickup Seth designed came to be known as the humbucker. Gibson Humbucker Pickup Patent Seth's pickup patent was filed on June 22, 1955. Gibson added the new pickups to steel guitars in 1956, and in 1957 on electric solid-body and arch-top guitars, including the popular Les Paul Model. During 1957, a small black decal with gold lettering was added to the underside of the pickup. This decal read, "PATENT APPLIED FOR". Later, as the vintage guitar market evolved from savvy recording artists to local musicians, these pickups became known as the 'PAF'. Gibson PAF Decal Seth Lover received his approved pickup patent, #2,896,491, on July 28, 1959. By late 1962, Gibson changed the decal to read, "PATENT NO 2,737,842". It is interesting to note that the patent number listed on the decal was not for the pickup design, but for Les Paul's trapeze tailpiece. One can assume Gibson was creating a research roadblock for the competition. Or, was it simply a typo? The competition idea seems more credible, but silly, as these new decals appeared 7 years after the pickups were first installed on Gibson's instruments. Patent Number Decal The Making of a PAF Between 1959 and 1960, Gibson made PAF pickups with white and black plastic bobbins. Prior to this point in time, both of the bobbins were black. These oblong bobbins are exposed when the pickup's metal cover is removed. Thus, some PAFs are referred to as double black (two black bobbins), zebra (one black and one white bobbin) and double cream (two white bobbins). Because collectors and players want the rarest possible instruments, amps, parts, etc?vintage double cream and zebra PAFs command higher prices that the more common double black pickups. These variations of PAF pickups with cream bobbins are also in their prime period of construction from 1956-1960. The bobbin's color does not influence the sound of the pickups. It's purely cosmetic, but creates a very cool image. Double Cream PAF From 1956 until sometime in 1961, Gibson used different Alnico magnets in their PAFs. Alnico magnets (composed primarily of the alloys ALuminum, NIckel, and CObalt) come in a variety of grades based on their magnetic strength. Gibson used the same magnets (size and grades) available for their P-90 pickups. It seems Gibson randomly used Alnico 2, 3, 4 and 5 grade magnets in PAFs until 1961. The higher the magnet's number, the higher the magnetic strength. By 1961, Gibson began consistently using a smaller size Alnico 5 magnet. Generally speaking, decreasing the flat (top) side size of these magnets decreases the power of the pickups. As for wiring, Gibson used a braided shield wire for connection to the control pot. The pickup bobbins were wound with #42 (plain enamel) wire. The bobbin wire appears purple versus later versions that appear reddish. Gibson eventually switched to polyurethane coated wire around 1963. The capacitance of the coating is determined by thickness and material composition, and this influences the sound of the pickup. When coatings change, the sound signature of the pickup can change. The amount of wire (and coating) wound on each bobbin determines the DC resistance and other factors, including sound characteristics. When the bobbins are wound with more than a nominal amount of wire, the more power they exhibit, thereby sounding fatter in the midrange with less treble. The resonant peak of the pickup changes as more or less wire is used. Due to human intervention and the wide-tolerance of the winding machines and the test equipment used by Gibson from 1956-1961, PAF pickups during these years usually measure between 7.5 - 9.0 thousand ohms (K ohms). I have measured an original, unaltered 1960 PAF in the neck position of an ES-335 guitar at 10.0 K ohms! After 1961, almost all PAF and patent number decal pickups seem to measure 7.5 K ohms +/- .25 K. PAF Magnet and Wiring A Talk With Lindy Fralin Now that we have a handle on the basics, let's discuss various conclusions this information implies. I asked pickup guru Lindy Fralin to help us decipher some of the mysteries and the myths of the PAF pickup. Lindy Fralin runs Lindy Fralin Pickups, a company based in Richmond, Virginia. Lindy is a passionate pickup scientist who has spent countless hours trying to understand how all types of pickups were designed and constructed. He can discuss the entire technical subject spectrum about resistance, inductance and all the other pickup characteristics. In 1998, Lindy's PAF humbucker was chosen as the best sounding pickup versus five other PAF-type models in a magazine product test. Let me relate to you some of Lindy's thoughts on the subject of PAFs. Lindy said that many of the original PAF pickups from 1956-1960 sound different depending on the magnet and the amount of wound wire. His preference is for the PAFs that used an Alnico 4 magnet, with approximately 8.0 K ohms. He said they sound a bit more robust with a better defined high-end. So Lindy uses the Alnico 4 in his version of the PAF humbucker. Lindy admits that theories regarding degraded wire coatings and micro-cracks in the wire of original PAFs have been discussed. However, these ideas have not been fully quantified as to the effect on the sound signature of original PAFs versus PAF-type pickups made today.
Lindy stated that the 1961-1963 PAF and the 1963-1975 patent number decal pickups are very consistent in sound and resistance at 7.5 K ohms nominally. They have the smaller Alnico 5 magnet and some have different bobbin wire. They sound different when compared to early PAFs with more high-end and less warmth, especially in the mid-range. Although some players prefer the sound of the later patent number humbuckers, including Michael Schenker of UFO and MSG. Michael's 1971 Medallion and early 1975 Flying V guitars included these patent number pickups as standard equipment originally. Another interesting fact Lindy mentioned was that when he measured original PAFs, many times, each side of the pickup's double-coils exhibit a different value due to the manufacturing issues mentioned previously. For example, one side might read 3.5 K ohms and the other 4.5 K ohms. He said this often contributes to better sound, not worse. With slightly mismatched coils, certain frequencies are cancelled and others are phase-shifted. This results in a pleasing sound according to Lindy. Since Jimmy Page and Billy Gibbons won't let you tear apart their pickups for analysis, we can only wonder if these historically significant guitars have mismatched PAFs. This is getting interesting. Lindy believes so strongly in the mismatched coils idea that he created a new pickup called the UNBUCKER. He said this design was developed because of the lack of clear high end on the wound strings of most side-by-side two coil pickups. The sound from a humbucking pickup is created by string vibration being sensed in two places (two coils) rather than one. He says the UNBUCKER creates a humbucker that looks normal but sounds brighter on the wound strings. The other point Lindy mentioned concerns the pickup's efficiency. If a pickup design is efficient, it will capture most of the frequencies the guitar is producing and be loud. The trick for all pickup designers is to make an efficient pickup with a pleasing frequency spectrum. Zebra PAF Exploding A Few PAF Myths 1) All PAFs sound the same - Definitely not. The changes in construction and materials ensure that some PAF pickups were made outside of the normalized average. PAF pickups will sound different in different guitars as well. Various wooden guitars absorb certain frequencies and resonate others. 2) Higher resistance PAFs sound better - Not necessarily. Other factors affect the sound, including capacitance, inductance and pickup efficiency. Also, higher resistance pickups tend to have lower high frequency response. 3) PAFs sound better because the magnets have weakened - Guitar magazines articles in the past have reported that the ageing of the magnets over 40 years has changed them and produced a better sounding PAF. However, magnet manufacturers report that these Alnico magnets only lose 0.2 - 2.0 % of their strength over 100 years. It's not weakened magnets. Beck, Clapton, Page, Gibbons and the other PAF guitar players made a bunch of great music with these instruments in the late 1960s when the pickups were only 10 years old. If the ageing story made sense, 1970s Gibson humbucker pickups should sound wonderful with 20+ years of ageing, but they still exhibit less warmth with more high-end than PAFs. Just buying a PAF won't ensure you sound like Jimmy Page, Eddie Van Halen or Billy Gibbons. Other factors play a part, including the aforementioned players great talent. Also, the amplifier, string gauge, action set-up and the resonance of a particular guitar also factor into the equation. Seth Lover's humbucker pickup is an efficient and beautiful design. Yes, some of the wiring and coatings are made different today and don't replicate the processes of the 1950s. Still, I think the leaders of the replacement pickup market, including Lindy Fralin, Seymour Duncan, Tom Holmes and others make great PAF-like pickups that probably get you 80-90% of the sound of the original PAF for 10% or less of the cost of a vintage pickup. However, there will always be individuals that will pay for the real PAF because they want the thing everyone is copying. You decide which pickup fits your needs and budget. In Part 2 of the PAF Story, we will discuss how pots and capacitors change the sound of your pickups. How your sound changes by removing the pickup cover. Also, how the set-up (action and pickup height) changes the tone. We will also discuss the T-Top patent number pickups that followed the PAFs. ---------- Part 2 In Part 1 I discussed the origins of the PAF pickup and exposed some of the more prevalent myths. Next, I want to explain a few of the adjustments that can be made to humbucking pickups, including the guitar's controls and set-up to influence the amplified sound. Also, I'll discuss the T-Top pickups that came after PAFs. Volume Control Pot - Changing the volume pot (potentiometer) resistance value can marginally enhance the high-end response. A higher K Ohm value will make the pickup sound a bit brighter. Conversely, a lower value will enhance the mids and lows by reducing the treble sound signature. For PAF humbuckers, Gibson used a 500K Ohm pot and Fender used a 250K Ohm pot for most of their single-coil pickup guitars. Tone Control Capacitor - Changing the capacitor connected to the tone pot effects the treble response of the pickup. Different cap values roll-off the treble at different frequencies. A higher value cap will reduce more of the pickup's treble response. Vintage Fender guitars used caps from 0.1mfd to 0.05mfd. Gibson used different cap values with 0.02mfd and 0.01mfd being popular choices. Removing the Pickup Cover - Removing the metal humbucking pickup cover will marginally brighten the pickup. Be aware that removing the cover improperly may damage the windings on the coils and make your pickup useless. If a pickup is damaged in this manner, one or both coils will have to be rewound. Setting the String Height - Raising the action (string height) of the guitar's strings will generally allow for a clearer and cleaner amplification of the notes and especially chords. Also, the string gauge affects the guitar's amplified tone. Higher gauge strings have more mass and ultimately change the frequency response, overtones and sustain. Setting the Pickup Height - Raising the pickup close to the strings will increase the output (sound louder). The downside is that a strong pickup magnet may dampen string energy (reduce sustain) and may pull the string slightly out-of-tune. Lowering the pickup may produce a clearer and cleaner signal with less output. Remember, the neck pickup will sound louder than the bridge pickup (given the pickups are the same output specs and the same distance from the strings). You can adjust the pickup height to equalize this output difference if you switch between the neck and bridge pickups while playing live on stage and want similar sound levels. T-Top Patent Number Pickups -The T-Top patent number decal pickups followed the non-T-Top patent number decal pickups that followed the original PAFs. The patent number decal pickups were produced from 1962 until 1975. During 1975 Gibson stamped the patent number into the bottom of the pickup's base and these markings lasted until the early 1990s. By 1967 Gibson added a mold mark on the top of the pickup bobbins in the form of a 'T', with and additional small number. The T-Top humbuckers, as they are called, sound very similar to Gibson humbuckers made from 1961-1967. Most of these pickups measure a resistance of 7.5 K Ohms nominally. The existence of T-Top humbuckers helps to determine if the pickups are original equipment for a particular guitar. Vintage guitar dealers assign more value to non-T-Top pickups made before 1967 than T-Top or later pickups. These T-Top pickups have the smaller Alnico 5 magnet and sound different when compared to early PAFs with more high-end and less warmth. Many players prefer the sound of the later patent number humbuckers, including Michael Schenker. Gibson's 1971 Medallion and early 1975 Flying V guitars included these patent number T-Top pickups as standard equipment originally.
Lindy Fralin on pickups: wax potting Lindy Fralin operates a custom pickup-winding business in Richmond, Virginia, offering replacements for many of the standard magnetic pickups used by guitar builders (Strat®, Tele®, humbucker, P-90, and Jazz Bass® styles). Besides making stock-output reproduction pickups, Lindy and his small crew provide one of the world's best rewinding/repair services for vintage pickups, and will custom-wind new Fralin pickups to suit your needs. Lindy was one of the key instructors at the Great Northwoods Seminar in October ’95. He writes: We try to custom-wind pickups to give a customer the sound he's looking for. I understand guitar sounds, and I'm a player. I always loved the Strat neck and middle pickup, but thought the bridge pickup was too thin. That's the reason I got into winding in the first place. Our assembly and winding is done by hand from American-made materials, and it's the hand-winding which gives our pickups the authentic vintage tone. We rewind and repair pickups, along with making our own. What we can't do is change a pickup's string spacing, or reproduce missing parts (we're not that type of manufacturer). Except for Fender, most vintage pickups were not potted, or at least not well-potted (we “pot” pickups to stop microphonic feedback and to protect them from the elements). Some guitar makers pot by brushing on wax, others wrap the coil with tape. All new Fralin pickups come potted, and we pot rewinds that were originally potted. If we're asked, we will pot Gibson and other pickups as long as we think it won't damage them. In the photo of Lindy above, note the Tupperware spool holder sitting on the chair behind him. That's how they feed the wire to the machine. I pot with wax because it's non-toxic, easy to deal with, cheap, and you can undo something if it goes wrong. I don't want to work on epoxy-potted pickups because you can't get to the parts to rewind them, and epoxy only coats the parts—it's too thick to penetrate the coil. Hot wax is thin enough to penetrate completely into the coil, which is what you're after, and it keeps everything from vibrating. Microphonics is that squealing or knocking sound you hear when you tap on a pickup. A good example of microphonics at its worst would be the Fender Telecaster bridge pickup—not only do you have a coil of wire and magnets, but you have a steel plate under it and a steel bridge around it. Fender used to mount the steel plate after the pickup had been potted, and that's why the Tele is so notoriously microphonic—the steel plate vibrates. For that reason, I pot my Tele bridge pickups after the plate is mounted. [font=Arial,Helvetica,sans]On my Teles, I also pot the bridge itself! I melt a few drops of hot wax (you could use a candle) onto the bottom of the bridge in the area where it surrounds the pickup, spread the wax thin with a hot soldering iron, and press it to the guitar body while it's still warm. You can't see it once the bridge is remounted, and the thin layer of wax acts as a shock absorber between the bridge and the body. Fender potted most of their pickups in wax, but they also did a number of them in lacquer. Lacquer is okay, but it doesn't penetrate as well as the hot wax does, and it's harder to repair a pickup that's been lacquered because you can't peel them for repair (“peeling” is unwinding the layers of copper wire to find a break in the coil or a spot which is rusted or corroded. Rusted steel, corroded copper, or a combination of both, are the most common causes of dead pickups, or pickups which die a slow death.) Wax-potted coils unwind nicely, unlike lacquer-potted coils which might as well be glued together. You can recognize lacquer by its thin, shiny, wet-looking coat, compared to wax which is thicker and more dull-looking. Fender used wax more often than not, but sometimes they only dipped the pickups—whereas I soak mine. Today, most of the modern pickup makers like Seymour Duncan, Van Zandt, myself and others, use wax for potting. We only charge $10 plus shipping to pot pickups, so of course it's easier for most people to just send them to us rather than doing it themselves. You can pot your own pickups for a minimum investment, however—I tell customers how to do it all the time—but you have to follow certain safety precautions, and probably only the really serious professional shops will set up to do it. Mix canning paraffin and 20% beeswax by heating them in a pot. Paraffin expands and contracts with temperature changes, and the beeswax nullifies most of that. The heating is the dangerous part—never try heating your wax on the kitchen stove or in a microwave oven because hot paraffin, and especially paraffin vapors, can ignite. Our wax pots are the mid-sized, heavy-duty deep fryers used in some home kitchens and small restaurants thirty years ago. We leave them at 150°F all day long, and pickups can sit in there for an hour or more without problems (ten or fifteen minutes is our normal potting time). At 150° you won't harm a pickup, but use a kitchen meat thermometer to check the temperature. Stew-Mac's Hot Glue Pot makes a great single-pickup wax-pot for a small shop; it's UL-approved, and is designed to run all day. I had to lower the thermostat a little, though (see note below). Experiment with potting by heating the wax outdoors, or maybe in the garage. Once you find the 150° setting, and know what you're doing, then use it in your shop. Provide adequate ventilation, too—we pot under an exhaust hood which vents to the outdoors. [Note: Stew-Mac's Hot Glue Pot (product #668) has a thermostat designed to heat hide glue to about 145°. The pot, with glue or wax, is meant to be at least 2/3 or 3/4 full. It can operate with less liquid without damage, but it may get too hot (perhaps that was Lindy's problem). Extra metal liners are available (so you could have one for wax and one for glue); ask our phone staff for part #668-P.] Wax pickup potting guidelines The wax-pot's metal walls may be hotter than the wax itself, so don't touch the pickup to the walls of the pot; instead, use some sort of hanger to suspend the pickup in the wax. Paul Reed Smith uses a layer of marbles in the bottom of the pot. [font=Arial,Helvetica,sans]If the wax is smoking, it's too hot (but you should be checking the temperature with a meat thermometer anyhow—150° or less). “Cook” a pickup until all the air bubbles have stopped coming out, usually in 10 to 20 minutes. [/font] [font=Arial,Helvetica,sans]Wax is messy, very flammable, and it'll burn you, too. So for safety's sake, stay with the wax-pot and be sensible. It splashes too, so wear safety glasses! Don't remove the tape from Gibson-style pickups. The heat may cause the tape to unwrap, so stretch rubber bands around the pickup to hold the tape in place, and only remove them after the pickup has cooled.[/font] [font=Arial,Helvetica,sans]Remove the excess wax with a paper towel as soon as the pickups are cool enough to touch.[/font] [font=Arial,Helvetica,sans] [/font] [font=Arial,Helvetica,sans]Adjusting the thermostat on Stew-Mac's glue pot We don't suggest that you take the pot apart all the time to adjust it, but here's how to do it: Remove the inner basket Remove the two small screws holding the metal liner and then pull the liner out as far as it will go and lay it on its side (photo below). Handle the inner liner gently. [/font] [font=Arial,Helvetica,sans]Adjust the hex nut counterclockwise to lower the heat. One-sixth (one hex point) of a turn will change it 20° to 25°. Re-assemble, and let the pot run for about 1-1/2 hours while the thermostat readjusts. [/font] [/font]