The Super Humbucking mystery

Discussion in 'Gibson SG' started by JohnP, Oct 9, 2012.

  1. JohnP

    JohnP Member

    Joined:
    Oct 9, 2012
    Messages:
    499
    Likes Received:
    386
    Location:
    Stockholm
    Hi guys, I would like some support. Could you help out?
    I use a few different guitars, one of them is a ’78 SG standard with original pickups. According to the 1978 catalog it is fitted with the “super humbucking pickups” (sometimes called Tar-backs).

    I have measured pickup DC resistance, quick and dirty with a patch cable in the tele jack. I get accurate measurements for all my guitars with this method, but the ’78 SG gives me a headache:

    The neck pickup shows 5,2 kohms and the bridge pickup shows 7,54 kohms. I find this strange and it leads to a number of questions:

    1. -Is this original SG wired in a way that this easy way of measuring fails?
    (The method works for my Gibson ES 335 and for my Fender Strat, what is different?)

    2. –What’s the specification on the 1978 super humbucking pickups?
    (Gibson.com doesn’t even provide specifications on their current line of pickups. I guess they have decided to let their products do the talkin’ and let the Seymore Duncans of the world dwell on the details…)

    3. –Was the “super humbucker” the standard Gibson humbucker in 1978 and did it differ from the original Super humbucker by Bill Lawrence?
    (From what I have read the Bill Lawrence Super humbucking pups are supposed to be 1,5 x hotter than a classic ’57, which isn’t exactly what I have been able to measure)

    4. Nowadays the SG line comes with hotter pickups at the bridge, than at the neck. -Was it always like this and did the original Bill Lawrence super humbuckers come with different specs for the bridge and the neck?

    5. Magnets weaken over time, and this baby is 35 years. -Could it be that the DC resistance has dropped due to age?
    (I tell you, this SG sounds better today than it ever did, and I don’t know if it has to do with the pickups, the wood or both….)


    I don’t really expect anyone to have a comprehensive answer to all this questions, but if you have any input to just one of the questions, please respond. Thank you :wave:
     
  2. TattooedCarrot

    TattooedCarrot Well-Known Member

    Joined:
    Feb 7, 2006
    Messages:
    1,051
    Likes Received:
    353
    Location:
    SoCal
    Tar backs, designed by Bill Lawrence when he worked for Gibson.

    Gibson tar back specifications:

    Inductance 4.7 Henries
    Resonant Peak 5.8 Khz
    DC resistance 7.8 K ohms (at 1000 cps)
    Impedance High
    Two Active upper coils
    One Ceramic Magnet (indox 7)
    Adjustable pole pieces
    Removable pickup cover
    2 point height adjustment

    [​IMG]
     
  3. JohnP

    JohnP Member

    Joined:
    Oct 9, 2012
    Messages:
    499
    Likes Received:
    386
    Location:
    Stockholm
    Thanks TC, Very helpful.
    This means that my bridge reading is spot on: 7,73 k compensated for volume pot resistance 300k.
    But it’s way off at the neck. –Was it the same spec for both pickups, neck and bridge?
     
  4. BlackSG91

    BlackSG91 Well-Known Member

    Joined:
    Sep 19, 2012
    Messages:
    3,619
    Likes Received:
    1,358
    Location:
    Oshawa, Ontario
    I've measure the pick-up on my '98 American Std. strat and the neck and middle measured 5.85kohms while the bridge measure 7.3kohms. The bridge pick-up is usually higher because the string vibration is not as loud at the bridge, where the volume of the strings is loudest at the neck position. Explains the difference in impedance. When I change the strings on my SG, I definitely would to measure the pick-ups out of curiosity.:hmm:
     
  5. TattooedCarrot

    TattooedCarrot Well-Known Member

    Joined:
    Feb 7, 2006
    Messages:
    1,051
    Likes Received:
    353
    Location:
    SoCal
    There are no markings to indicate bridge or neck versions so I don't think they should be different. I don't think a degaussed magnet would result in a lower DC resistance as that's the wire ans not the magnet. I need to put mine on a meter and see exactly what they read. Does yours work? Does is sound right? I think they are actually Pretty good sounding pickups.
     
  6. Col Mustard

    Col Mustard Well-Known Member

    Joined:
    Sep 29, 2009
    Messages:
    7,997
    Likes Received:
    8,061
    Location:
    Tucson AZ
    John, I think that your statement #5 is the key to the whole can of worms, if you don't mind me mixing metaphors on a wet Wednesday morning. Gibson in the late 70s was reeling from intense competition from Keyboard innovations (synths) and Super Strat shredder guitars and the Punk Rebellion and Disco Balls. Oh yeah and that 'guy from Mars who's given up on eatin' cars and now he only eats GUITARS...' So they Gibson was tryin' to stay competitive and innovative, and they came up with your SG.

    If your guitar sounds better now than it ever did, DON'T ROCK THE BOAT. *grins Be glad that whatever is under all that tar is still working for you. Old guitars have their own mystique, and 70s SGs are now regarded as true classics. (!)

    I couldn't give you any technical info like these other guys, they seem to know their stuff. But I thought #5 was the telling statement. And guitar magnets don't decay very quickly, I believe it's hardly measurable over half a century. So it's prolly the wood, and all the psychic echoes of all the songs and chords and solos over time that gives your guitar its soul.
     
  7. JohnP

    JohnP Member

    Joined:
    Oct 9, 2012
    Messages:
    499
    Likes Received:
    386
    Location:
    Stockholm
    @TC: Oh yes, works fine and sounds good too. I have lowered the neck pickup flush to the frame for more clarity and harmonics, bridge pickup is lowered a notch. Good output balance between the two pickups, and overall output about the same as my classic ’57 pickups. I made a DI recording comparing the SG (super humbuckers) and the 335 (classic ’57):

    The Super humbuckers have higher highs and more bass compared to the Classic ’57 which has a more pronounced midrange. The Super Humbuckers have a more scooped, wider sound in all pickup positions. The middle position, with both pickups active, has an outstanding clean sound, full bodied and shimmering (a great jazz-tone for sessions). The treble position has a distinct bite for crunch or lead distortion. The rhythm position is heavy bottomed with a sparkling top. I couldn’t ask for more.

    (of course, the test was done with two different Gibsons, with different woods, so one could expect more bass from the SG and more “wood-kernel“ from the 335, however the higher resonant peak of the Super Humbucker clearly adds to the treble side of the spectrum for a full tone.)

    @Col: “So it's prolly the wood, and all the psychic echoes of all the songs and chords and solos over time that gives your guitar its soul.” Most probably yes :fingersx: ….However, after some TLC, a good set up, and an effort to really bring out the best from the original electronics (i.e proper pickup set up and really finding the right strings, oh yes) this guitar has opened up.

    Therefore I say: Never change pickups before you have optimized the originals, but if you do, never trade your old ones because maybe they improve with age.

    I just have to know my pickups, they are vital to tone. Besides I have another guitar that might benefit from new pickups, so I’m trying to understand these Super Humbuckers that I like...
     
  8. JohnP

    JohnP Member

    Joined:
    Oct 9, 2012
    Messages:
    499
    Likes Received:
    386
    Location:
    Stockholm
    Mystery Solved!

    It turns out that the Super humbucking pickups actually came in two different specs:
    Treble position 7,5 K ; Rythm position: 5,5 K

    Don’t be fooled by the numbers, these are really sweet pickups and they have about the same output as the classic ’57.

    And here’s some advice from the man on Rating Pickups with DC Resistance:

    ”DC resistance is NOT a power rating; it is the resistance of the wire in a pickup's coil at zero hertz, something that only occurs when the guitar isn't played. If some marketers use DC resistance as a power rating for an AC device, like a pickup, then they only show their ignorance. If we use DC resistance as a parameter, we disregard the fact that, due to Pe and other conditions that result in eddy currents, the effective resistance (Rac) is frequency dependant.
    DC resistance (Rdc) tells you as much about a pickup's tone and output as the shoe size tells you about a person's intelligence! ” (Billlawrence.com)
     
  9. BlackSG91

    BlackSG91 Well-Known Member

    Joined:
    Sep 19, 2012
    Messages:
    3,619
    Likes Received:
    1,358
    Location:
    Oshawa, Ontario
    I've read that article before! Especially about the eddy currents and all. Interesting. There's a lot of factors that affect the sound of a pick-up like inductance & so on. I use impedance as a general guide, but I know it don't tell the whole story. Of course hearing the pick-up is another thing.:hmm:
     
  10. TattooedCarrot

    TattooedCarrot Well-Known Member

    Joined:
    Feb 7, 2006
    Messages:
    1,051
    Likes Received:
    353
    Location:
    SoCal
    All things being equal, DC resistance is usually a general indicator of output. But it in itself is not the output measurement. DC goes up as you add more wire. Again, assuming the wire is the same on two pickups, giving one more turns than the other will change the DC resistance to a higher reading, and increasing the output (more wire = more output). Or so I think anyway, not a real technical person. But the size wire, material, wind pattern, magnet type, size and strength are all factors in a pickup's output.
     
  11. Col Mustard

    Col Mustard Well-Known Member

    Joined:
    Sep 29, 2009
    Messages:
    7,997
    Likes Received:
    8,061
    Location:
    Tucson AZ
    hah... judging by my feet size, I must be grandioso intellegencia...
     
    SG Champagne likes this.
  12. Jackal

    Jackal New Member

    Joined:
    Jul 10, 2013
    Messages:
    1
    Likes Received:
    1
    Location:
    Minnesota, USA
    WOW all I have is this:
    http://img.photobucket.com/albums/v108/JackalGuitars/Scan87Catalog.jpg
     
    BlackSG91 likes this.
  13. TattooedCarrot

    TattooedCarrot Well-Known Member

    Joined:
    Feb 7, 2006
    Messages:
    1,051
    Likes Received:
    353
    Location:
    SoCal
    Fixed

    I got my specs from a post on MLP, don't know the actual source but whats on your catalog seems to match. The removable pickup cover doesn't sound right though, these things are anything but removable.
     
    BlackSG91 likes this.
  14. 7904

    7904 Member

    Joined:
    Sep 23, 2012
    Messages:
    96
    Likes Received:
    85
    I love my tarbacks. And readings be damned, the tarbacks in my 79 hit an amp hotter than the 490 in my 04.
     
  15. sneakerpimp

    sneakerpimp Member

    Joined:
    Dec 25, 2009
    Messages:
    586
    Likes Received:
    158
    Location:
    The O.C.
    anyone know how they compare to the Velvet Brick on my '82?

    [​IMG]
    [​IMG]
    [​IMG]

    it's supposedly also a Super Humbucker. it measured in the 7~ range by the shop that sold it to me.
     
  16. rfiori9

    rfiori9 Active Member

    Joined:
    Nov 1, 2015
    Messages:
    111
    Likes Received:
    118
    Anybody know what the middle tarback should read on my 77 custom SG? My neck and bridge read 5.2 and 7.4
     
  17. rfiori9

    rfiori9 Active Member

    Joined:
    Nov 1, 2015
    Messages:
    111
    Likes Received:
    118
    Also has anyone ever seen one with 2 leads?
     

Share This Page