Dub-T-123 Posted April 13, 2014 Posted April 13, 2014 It seems like the bridge pickup in my SG is weaker than when I bought the guitar. I installed a different bridge pickup for a couple years and stuck the original 498t to my fridge during the time it was out. I put it back in (quite a while ago) and it has felt noticeably weaker than the neck pickup since then. I never remember having that issue before Both pickups sound excellent so it's not a big deal but I'm curious why this happened. I guess this thread should be called "Hey Searcy come school me please"
capmaster Posted April 13, 2014 Posted April 13, 2014 Any permanent magnet will lose some field strength with time. This is the reason why reputable pickup manufacturers use pre-aged magnets which will retain their magnetic remanence virtually unaltered over the years.
Dub-T-123 Posted April 13, 2014 Author Posted April 13, 2014 Maybe its your hearing that's become weaker? :P :) What?
Guest Farnsbarns Posted April 13, 2014 Posted April 13, 2014 Any permanent magnet will lose some field strength with time. This is the reason why reputable pickup manufacturers use pre-aged magnets which will retain their magnetic remanence virtually unaltered over the years. The loss of magnetism in a given environment Is directly proportional to age. The loss does not slow down or accelerate the older the magnet gets. This is regardless of magnet material. The only reason your magnets would lose power is due to other magnetic forces re-aligning the particles. While this happens constantly it is a VERY slow process unless stored close to other powerful magnetic fields. More likely that you have strings that have taken on a magnetic field from the previously installed pickups. You don't say anything about strings in the OP. Have you replaced them, and how recently?
Dub-T-123 Posted April 13, 2014 Author Posted April 13, 2014 Hmm that goes along with my theory that some component in my fridge was realigning the magnet making it sound weaker I've changed the strings many times since putting the pickup back in. The strings that are currently on it are a couple weeks old
Rabs Posted April 13, 2014 Posted April 13, 2014 What? I said MABYE YOU SHOULDNT STAND NEXT TO THE SPEAKER
Dub-T-123 Posted April 13, 2014 Author Posted April 13, 2014 I said MABYE YOU SHOULDNT STAND NEXT TO THE SPEAKER Oh, no I haven't wrecked any beakers
Rabs Posted April 13, 2014 Posted April 13, 2014 Oh, no I haven't wrecked any beakers a koo koo ka choo? :)
capmaster Posted April 13, 2014 Posted April 13, 2014 The loss of magnetism in a given environment Is directly proportional to age. The loss does not slow down or accelerate the older the magnet gets. This is regardless of magnet material. The only reason your magnets would lose power is due to other magnetic forces re-aligning the particles. While this happens constantly it is a VERY slow process unless stored close to other powerful magnetic fields. More likely that you have strings that have taken on a magnetic field from the previously installed pickups. You don't say anything about strings in the OP. Have you replaced them, and how recently? Degradation of magnetic remanence in a given environment is following an exponential curve. So the absolute value of loss per period will decrease over time. Pre-aging is done in order to shift the deterioration into a range which is less obtrusive during use. In case the strings are magnetized in reverse due to reverse polarity of the previous pickup's magnet(s), this will indeed attenuate signal level.
capmaster Posted April 13, 2014 Posted April 13, 2014 Maybe its your hearing that's become weaker? :P :) What? I said MABYE YOU SHOULDNT STAND NEXT TO THE SPEAKER Oh, no I haven't wrecked any beakers a koo koo ka choo? :) [lol]
krock Posted April 13, 2014 Posted April 13, 2014 I read a while back about how people who stand their guitar up next to a speaker will end up over a long period of time with a weaker magnet in their pickup
surfpup Posted April 13, 2014 Posted April 13, 2014 Hmmmm... pickup is not as hot... Maybe putting it on the fridge cooled it off?
Ryan H Posted April 13, 2014 Posted April 13, 2014 Temperature can also play a part. Magnets weaken under prolonged periods of high temperatures, and the DC resistace of the coil itself is also affected by temperature; electrons flow more easily through warm conductors than cold ones. -Ryan
Dub-T-123 Posted April 13, 2014 Author Posted April 13, 2014 Hmmmm... pickup is not as hot... Maybe putting it on the fridge cooled it off? Heyo! Actually the pickup was always very warm. It stayed on a part of the fridge that is always hot for some reason Here's where I probably start to sound like a dingus (if I haven't already).. The pickup sounds better to me now than it did before. It sounds less harsh than used to. It also seems more prone to microphonic feedback
Ryan H Posted April 14, 2014 Posted April 14, 2014 Heyo! Actually the pickup was always very warm. It stayed on a part of the fridge that is always hot for some reason Here's where I probably start to sound like a dingus (if I haven't already).. The pickup sounds better to me now than it did before. It sounds less harsh than used to. It also seems more prone to microphonic feedback Yep, as I stated above, prolonged exposure to heat weakens magnets. Weaker magnets will generally be a little softer spoken (hence part of the reason Alnico 2 has smoother highs and a softer, looser bass response than Alnico 5, for example). They'll obviously put out a weaker magnetic field as well, hence the volume drop. Move it closer to the strings if the volume difference is a problem. -Ryan
capmaster Posted April 14, 2014 Posted April 14, 2014 Temperature can also play a part. Magnets weaken under prolonged periods of high temperatures, and the DC resistace of the coil itself is also affected by temperature; electrons flow more easily through warm conductors than cold ones. -Ryan DC resistance increases in metals with rising temperature which is called PTC, positive temperature coefficient. The colder the metal, the better the current flow. However, the difference is large for output transformers and speaker coils which will suffer fading from heat, but small for magnetic pickups. Semiconductors like bipolar junction transistors and diodes have NTC characteristics, negative temperature coefficient. They will conduct better with increasing temperature which would lead to destruction without current limiting components. Field effect transistors have a PTC and will conduct less when becoming warmer. Same is valid for valve/tube plates, but not for cathodes of course.
Ryan H Posted April 14, 2014 Posted April 14, 2014 DC resistance increases in metals with rising temperature which is called PTC, positive temperature coefficient. The colder the metal, the better the current flow. However, the difference is large for output transformers and speaker coils which will suffer fading from heat, but small for magnetic pickups. Semiconductors like bipolar junction transistors and diodes have NTC characteristics, negative temperature coefficient. They will conduct better with increasing temperature which would lead to destruction without current limiting components. Field effect transistors have a PTC and will conduct less when becoming warmer. Same is valid for valve/tube plates, but not for cathodes of course. My bad, final exam studying has scrambled my brain... -Ryan
Jimi Mac Posted April 14, 2014 Posted April 14, 2014 Heyo! Actually the pickup was always very warm. It stayed on a part of the fridge that is always hot for some reason Here's where I probably start to sound like a dingus (if I haven't already).. The pickup sounds better to me now than it did before. It sounds less harsh than used to. It also seems more prone to microphonic feedback If they ever got warm enough to change, even subtly, any wax potting that could have made part of the difference... I've heard lots of guys talk about pickups deteriorating over time with use. Guys who gig alot and play in environments where they sweat profusely can cause changes in the pickups. I don't know if this is like a normal short from moisture or if the deterioration is different with possibly a mixing with the wax making it thinner or some of the oils in the sweat from our skin & body chemistry simply breaking down the wax potting or coating the coils. I hear guys talking about having pickups re-wound because the windings simply deteriorated with such infiltration of sweat and bio-material and dust all mixed together causing a tarnishing or residue to coat the coils over time like residue on aged strings... I don't think it's anything unique, I just think the pickup needs to be inspected for any breakage or deterioration in the coils or wiring/solder connections and to possibly be re-potted... Possibly too a new magnet might brighten it back up and restore some of that clarity/presence... If the wax potting is deteriorating you'll find some great tonal differences. Many of the original PAF's were left unpotted purposely for extra cutting tone, although the microphonics and feed back that are created in such circumstances can be quite a tightrope walk to play live, they often sound fantastic when tweaked-in to optimum settings... Not sure I helped much, and my own ignorance makes me a little uncertain of some of the info I'm passing along too...
brundaddy Posted April 15, 2014 Posted April 15, 2014 So that's why I've been able to buy so many 1950s PAFs so dang cheap. They're all faded out!
Searcy Posted April 15, 2014 Posted April 15, 2014 Here's everything there is to know about age guitar magnets. http://searcysw.blogspot.com/2012/04/do-pickup-magnets-mellow-with-time.html?m=1
Dub-T-123 Posted April 15, 2014 Author Posted April 15, 2014 Thanks Searcy! So most likely I'm just imagining the difference? Also, how can I age my magnets to sound like Slash?
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