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I have a ibanez afj81 with a humbucker sized p90 (BKP Manhatten), which I nearly wanted to sell, because of the hum I got from the PU, but instead I thpought that it most be possible to reduce the noise to nearly nothing, like my strat PU. The reason I want to give it another try is the marvelous sound I get from the guitar with this PU.
Normally on a solid guitar you would have to shield the cavaties, but since it's an archtop, this procedure seems impossible. I thought about makeing some cavaties on my own. I'm going to build some boxes for the pot's, the jack and of course the PU. It's going to be some very thick and stable paper which I'll use to make some cavatie-boxes for the inside of the archtop.
For shielding I want to use copper film. So the idea is to proceed like one would do with a solidbody and its' cavaties.
My question is: Do the "box-shielding" need to be conneced with the ground?
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04-06-2014 06:32 AM
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I have the P90 version, the half-note. I have shielding done on my two archtops, with humbuckers it's excellent but it's sort of useless with P90s... I am thinking of modding my Godin to accept humbuckers (or an humbucker in a P90 format or sell it) to take care of this.
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so you didn't got rid of the noise with shielding? well I guess you would agree that the sound is beautiful with this PU, but the noise is a dealbreaker, especialy if you play alone or in small contexts like duo trio or in a ballad. So you would advice rather to get a humbucker instead?
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Hans my luthier told there was nothing to be done... I had another P90 guitar (a Les Paul), also shielded, also hummed a lot. Electricity in Portugal is very poor on lots of venues though...
I am actually happy I went the P90 route because I understood that what I really like is a an humbucker sound (fat and hum free) with the tight bass and clarity of p90s / single coils. So that's where I am headed... So for me it's not only hum but also tonal reasons (I find P90s to be too sensitive to pick attack and thin sometimes).
I would wait to see what the guys who do know this stuff properly have to say... and I would also contact Bare Knuckles. If you end up going the humbucker route I can give some ideas to get closer to the P90 sound.
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Thank you for your input! I guess, if it ain't help that much to shield, than I will definitely go back to humbuckers.
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That is my experience... and my luthier does know about this stuff. But I would wait to hear some other opinions, maybe there is a solution and I (and my luthier) don't know it! Good luck
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thank you Jorge
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I bought a tele and was told by two separate luthiers that the noise was inherent because it has single coils. As I was able to stop the noise by touching the strings I didn't believe them. I have, incidentally, had the same observation on guitars with humbuckers.
I bought graphite paint and only painted the wooden cavity, none on the pickguard. I made sure there was continuity on the bridge earth wire and on the pickup selector plate via the screws.
The two coats of paint took five minutes. Cost a couple of pounds. There is now no "inherent" noise from the guitar. Yes, if you introduce a noise source then the pickups will still pick it up but there is is no buzzing that stops when you touch the metal parts on the guitar.
The only caveat is that it reduces some highs but that's generally not undesirable with a guitar for jazzLast edited by Chimera1to1; 04-06-2014 at 08:58 AM.
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a couple of things.
Single coils hum. Unless they are active jobs like EMG or Noiseless (which aren't really single coils) they will hum.
Some hum worse than others (P90s are worse than strats, Jazzmasters are worse than P90s.. I haven't tried anything worse than JMs).
If you strings are grounded (99% of the time they are) touching the strings may make a difference in hum level. If touching the strings reduces the hum (or taking your hands off the strings increases the hum) then shielding can help (when you touch the strings your become grounded and you act as a shield for the pickup. I have heard some crazy theories... don't get me started)
Over shielding CAN affect the tone as mentioned, specifically in the highend. I went overboard with my JM. The pickups were SD and nice pickups. I changed the leads to the shielded Gibsonesque leads. Copper foil everywhere on the pg (the body was already shielded with paint and even copper foil in the pickup covers. Most of that was ok (maybe the braided wire was a little too much ) but shielding the covers just killed the tone. Sounded like a wet mattress made of concrete over the amp).
Done
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it seems that there is still hope. thank you guys.
meanwhile I just did an experiment. The PU is right at the moment not installed any more, so I soldered the PU to a jack and than I connected the jack with a guitar cable to one of my amps. What I realized was that in different settings like my normal position sitting to the amp, the noise was noticeable the same as I was used to. the amp is positioned on a stand, which is as tall as common table is, so it's in direct position to the PU. when I put the amp on the ground the noise level got better. So I tried to stand a few meters away from the amp, but the noise just got better if it was in a certain ankle to the amp.
What conclusions can be made out of this results? Is shielding an option in this case? I knew that a P90 wouldn't be hum free, but in the end people seem to be able to work with floaters without excessive hum and if I recall it right, than a floater is mostly a single coil.
By the way, touching the strings didn't help to reduce the noise level, when it was installed in my archtop.
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How about a dummy coil?
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The other route would be a noise suppressor pedal.
Or frantic volume control twiddling, which if you think about it, was designed to fall close to the pinky finger on Strats, Teles and Jazzmasters!
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I have heard (though not played first hand) that the Fralin "UN-buckers" are supposed to have more of a single coil vibe. You may want to try one of those. Also, there are pickup builders that produce noiseless P90s, can't recall specifically, but I think maybe Lollar or Kinman.
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Yes
Originally Posted by hans halmackenreuter
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the unbuckers are not completely quiet but better than a P90. They sound harsh to me though. I used to love them but a recent set I put in a 339 were very ugly sounding IMO. Originally Posted by yebdox
Never played a noiseless P90 that I liked. I like the virtual vintage strat pickups dimarzio makes but they sound *NOTHING* like a vintage single coil.
Box insulating the pickup doesn't help much because you the pickup will still sense electro-magnetic waves from the top. If it couldn't it wouldn't sense the string!
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The question then becomes: Are the strings electrically connected to the circuit ground? In a lot of archtops they are not. Originally Posted by hans halmackenreuter
Try this. Instead of touching the strings, touch the metal cover of the plug on the cord where it is plugged into the guitar. If the hum stops when you do that, then shielding may help.
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well I installed the PU again and tried as you told, but there was no change. But the more I read about this through the net, the more I am convinced that what I am talking about is rather more a buzz than a hum. Probably both. Originally Posted by kenbennett
I wrote Bare Knuckle about my situation and I am also curious about their respond.
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Since we are on this subject..what about crackling and static. i get a lot of this kind of noise out of a couple of particular guitars but some from all my guitar when I play my Mesa TA-25. When I unplug the cable all is silent. None of these are cheap guitars and most are older 60's and 70's guitars. I especially get a lot of static off the strings as I play. I have wondered if better components such as pots and switches along with rewiring the guitar with better wire would help. I have checked the grounds to the bridge and tailpiece and when I touch either one the static is reduced.
Thanks John
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Sam.. I'm sure you know more about this through experience than I do through theory but the hum thing has me a bit confused. Originally Posted by SamBooka
P90's and single coils act like an antenna. Since we're often in an environment full of RF range transmitters (fluorescent lighting, computer power supplies, electric motors, AC cycle hum, et al) there's plenty to pick up. The strength of the signal and how good of a receiver your pickup is for that particular frequency(s) drives how much hum is generated. Shielding greatly reduces the amplitude of incoming RF by shunting all frequencies to ground.
Since your pickup should only care about the magnetic field your strings are generating, seems that shielding the pickup cover shouldn't matter unless you put something ferrous between the strings and pickup poles. Also, if touching the strings reduces hum, it may or may not be related to RF. If the overall guitar ground plane is lacking (not enough metal and/or a poor connection) touching the strings can reduce hum. It's not uncommon for humbucker equipped guitars to have a hum due to the ground plane which, because the pup is phase cancelled, has nothing to do with RF. On the other hand, keeping the broad spectrum of RF low enough for P90's and single coils is harder but you also have to make sure your shielding is effectively shunting to ground. Of course, for all I know, the shielding geometry itself can act as an antenna screwing up your ground plan. Been awhile since I pulled out a Smith Chart.
Just seems like I'm missing something in all this. Thought that usually if touching the strings makes hum go away, you need to make sure you have a solid ground plane including your shielding.
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Noiseless P90s work when you use neck and bridge and the same time ONLY... no?
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Only if they are reverse wound/reverse polarity to each other. Originally Posted by jorgemg1984
My MIJ JM was like that.. they only way I could get it quiet.
Spook: when I get a chance I will read/respond to your post.. hopefully in a couple hours
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Actually.. no worries Sam. I realized after I posted it that I'm heading off into the deep end of the RF and electrical circuit pond and it would take a treatise to address. I'm going to do some reading online looking for answers. Since you already posted your experience I can use that as a reference point. Originally Posted by SamBooka
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First of all I want to thank everyone for your input. The problem is solved.
I conntacted BKP and they told me that from my describtion, that it is probably a grounding issue. So I bought new wire and I did all the wireing new. With an archtop this is crazy work, but now I finished everything and the result is great. There is still a little hum going on but not more than my strat. If I turn the vol knob to about 8, I can play any chordmelody or ballad without having to bother with any noise
In the end I am happy I gave the PU a last chance, since it's really what I wanted for my archtop.
For modern stuff I still prefer my semi or my solids but for more strait ahead this PU and guitar works well.
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That's excellent. I'm going to be installing 2 humbucker size P90 style pickups in the archtop I'm building now. So you give the Bare Knuckle a good review?
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Great to know Hans!
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