Bare Knuckle Pickups Forum
Forum Ringside => Guitars, Amps and Effects => Topic started by: Dave Sloven on March 03, 2014, 06:24:29 AM
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I've started some more upgrades to my SG Junior this week after installing a Stockholm P-90 last year.
Upgrades completed so far are shielding the cavities and installing a new custom harness.
Here's the specs on the harness:
Modern Style SG Junior Harness With Bleed Kit
1x .033uf K7 (Russian) Cap
2x 500k Mojo CTS pots
1x Switchcraft Jack
(http://i.imgur.com/qutkDfr.jpg)
Completely stock (that dark paint was conductive, but shield was not complete at all):
(http://i.imgur.com/gRTVNDg.jpg)
New harness (he included a spare 0.022 WD Music Mustard cap in case it turned out too dark)
(http://i.imgur.com/wEyystO.jpg)
Stockholm and new harness installed, with fully shielded cavities:
(http://i.imgur.com/zJpyoZB.jpg)
Phase 2 will be the installation of a Graph Tech TUSQ XL nut and ResoMax NW2 bridge.
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neat job - do you notice an improvement in the noise?
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I've only had the chance to check it on the solid state practice amp (a Roland 30X) so far, but even though the bridge and pickup are not set up properly yet - making it sound and play like cr@p - I seem to detect that the screech is not diminished, and seems to be a function of how close I stand to the amp. Only once I have it better set up and playing through the Peavey will I really be able to tell if it has improved at all.
These are the things I did in an attempt to reduce the noise:
1. painted all cavities and the underside of pickguard and control cavity cover with double layer of conductive paint
2. installed a piece of foam under the P-90
2. installed a harness made from shielded military spec wire
If those don't eliminate the noise I'd have to say that it's just a result of playing a 15.9KΩ P-90 through a high-gain Peavey amp with a screamer etc into the lead channel.
That is a recipe for the screechies but my Nailbomb-equipped Explorer with the same three measures taken doesn't make much noise at all any more, even with the MXR Custom Badass Modified O.D. set up as a boost.
Interestingly, the one thing my bandmates always notice is if the ISP Decimator G-String II has accidentally been switched off, as the Peavey makes quite a lot of hum and hiss when it is off. I think part of that might be where we practice - the electricity seems dirty.
The other thing might be that I was just muting poorly. I have to determine whether it is still screeching when I play, or if it is just when I am not playing. I am used to muting the Explorer at the moment and maybe I wasn't doing such a good job of that with the wraptail bridge.
Anyway I should have a better idea by the end of this week.
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i'll be interested in the results..
screeching is often caused by something being microphonic and then using a high amount of gain.
do you hear anything microphonic if you tap around the pickup?
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As the last poster said, check for microphonics if there are screeching sounds and ringing if you tap the PU. Are they potted?
I have a couple of P90 equipped guitars and anything more than moderate overdrive reveals their inherent hiss and hum. I can only imagine an overwound pickup would magnify this. Boosters and gain pedals make mine noisy and i have to stand a good few feet away from the amp when using them.
I think if I plugged them into a TV I would probably get a picture as they make such good aerials!
A classic sounding BKP humbucking version of a P90 would get my money!
A friend of mine has a Vox Virage with some interesting coaxial PUs - like a P90 but humcancelling. Not found them for sale alone though.
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Just looking at the space in the control cavity, you could look at a dummy coil? Not tried it yet - but I am intrigued by the idea now for one of my P90 guitars
Pic here...
http://www.ca-music.de/GITARRE/CA-SIX/abschirmung.html (http://www.ca-music.de/GITARRE/CA-SIX/abschirmung.html)
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I've only had the chance to check it on the solid state practice amp (a Roland 30X) so far, but even though the bridge and pickup are not set up properly yet - making it sound and play like cr@p - I seem to detect that the screech is not diminished, and seems to be a function of how close I stand to the amp. Only once I have it better set up and playing through the Peavey will I really be able to tell if it has improved at all.
These are the things I did in an attempt to reduce the noise:
1. painted all cavities and the underside of pickguard and control cavity cover with double layer of conductive paint
2. installed a piece of foam under the P-90
2. installed a harness made from shielded military spec wire
If those don't eliminate the noise I'd have to say that it's just a result of playing a 15.9KΩ P-90 through a high-gain Peavey amp with a screamer etc into the lead channel.
That is a recipe for the screechies but my Nailbomb-equipped Explorer with the same three measures taken doesn't make much noise at all any more, even with the MXR Custom Badass Modified O.D. set up as a boost.
Interestingly, the one thing my bandmates always notice is if the ISP Decimator G-String II has accidentally been switched off, as the Peavey makes quite a lot of hum and hiss when it is off. I think part of that might be where we practice - the electricity seems dirty.
The other thing might be that I was just muting poorly. I have to determine whether it is still screeching when I play, or if it is just when I am not playing. I am used to muting the Explorer at the moment and maybe I wasn't doing such a good job of that with the wraptail bridge.
Anyway I should have a better idea by the end of this week.
2 things:
- Did you also paint the pickup cavity?
- Did you ground the body/paint? A screw with a wire somewhere underneath the pickup should do.
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2 things:
- Did you also paint the pickup cavity?
- Did you ground the body/paint? A screw with a wire somewhere underneath the pickup should do.
Yes, if you look at one of the small photos in that montage above you can see the pickup cavity, and it also has the same paint underneath the pickguard covering the cavity area.
I did ground the paint this time, you can see that in one of the photos above. I actually used the pickup wire from an old slot car , cut the tang down a bit and screwed that into the cavity wall, painted over it thoroughly with the shielding paint, and tested the wire (and everything) with the continuity tester before soldering it to the back of the volume pot.
The pickup came from BKP wax potted. Ben was really good about overseeing the whole process, it was a custom build with the Stockholm winding in a Nantucket case. I put a piece of the foam from the bottom of the BKP pickup box in the bottom of the pickup cavity to reduce vibrations.
As you can probably tell I've done pretty much everything I can here ... the only thing I can thing off as a last resort is to paint the underneath of the plastic pickup cover with the shielding paint the next time I have the strings off ... I've read somewhere about people doing this, and it makes sense. It would have a similar effect to using a metal cover. Stockholms normally have metal covers (in the HSP-90 format) and on the BKP site it says "With the higher output of the Stockholm, dynamics are more controlled providing excellent sustain while the solid nickel silver covers provide an extra degree of screening to help reduce background noise."
Anyone know of any downside to painting the inside of the pickup cover?
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Just looking at the space in the control cavity, you could look at a dummy coil? Not tried it yet - but I am intrigued by the idea now for one of my P90 guitars
Pic here...
http://www.ca-music.de/GITARRE/CA-SIX/abschirmung.html (http://www.ca-music.de/GITARRE/CA-SIX/abschirmung.html)
That's a possibility. I do have the original pickup of course ... I assume that is just a pickup wired in via a push-pull pot. The guy who made my harness joked that I have room to hide a Mars Bar in there.
I wonder though exactly what causes the screeching. The dummy coil would address hum, but I'm not sure that hum is the issue here.
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I vote for the Mars bar! :lol:
I'm interested in the final result. Still like the salmon colour.
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A classic sounding BKP humbucking version of a P90 would get my money!
Yeah, a hum-cancelling P-90 would be the perfect pickup!
There are quite a few on the market - Kinman, Fralin, Lace, The Creamery, Kent Armstrong - but all quite expensive to just take a punt on. I would like to hear the Fralins, he seems like a guy with a good ear for vintage tone.
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i'll be interested in the results..
screeching is often caused by something being microphonic and then using a high amount of gain.
do you hear anything microphonic if you tap around the pickup?
When I tap the pickup I just get the usual tapping a pickup noise, the old 'bok bok' that you get with any pickup.
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I guess if you roll the volume off then the screeching stops?
If not then it could be an amp problem - probably a valve.
If yes, then its probably a microphonic pickup problem. When the screeching happens, mute the strings with your hand - does it continue? Then feel parts of the guitar if anything metallic is vibrating. Sometimes mounting springs and things like that can vibrate if they are loose which can cause microphonic feedback.
But most likely it is a microphonic pickup I think. BKP have a lifetime warranty, so I'd have thought they'd repot it for you if you asked.
Are you using really high levels of gain/volume? On one particular amp I tried at rehearsal I could get my ceramic warpig to go into microphonic feedback with loud high gain levels.
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A classic sounding BKP humbucking version of a P90 would get my money!
Yeah, a hum-cancelling P-90 would be the perfect pickup!
There are quite a few on the market - Kinman, Fralin, Lace, The Creamery, Kent Armstrong - but all quite expensive to just take a punt on. I would like to hear the Fralins, he seems like a guy with a good ear for vintage tone.
Philking tried some hum-cancelling P90s in his WezV SG. I tried said guitar also. They sounded sadly sterile. I forget which brand they were, but it was a boutique brand of some sort.
Don't P100s sound quite sterile too?
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Most comments on hum bucking P90s seem to say same - sterile or lacking something. So i have not taken the plunge. But i also feel the humcancelling postions 2 & 4 on my strat sound a little 'dead' too.
I may try a dummy coil from an old single coil PU I have to just switch in for high gain bits - from what I read they do not colour the P90 as much.
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I don't fully understand the dummy coil. Surely it has to be mounted in some relative way to the pickups? The the blueshawk it has a route parallel to the P90's sort of like the middle pickup on a strat. I don't see how you'd get the hum cancellation by mounting a coil in the control cavity. Maybe I'm missing something. I read a page saying that the dummy coil is demagnetised too, but I assume that just means the core is much lower flux density rather than absolutely zero.
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I don't fully understand the dummy coil. Surely it has to be mounted in some relative way to the pickups? The the blueshawk it has a route parallel to the P90's sort of like the middle pickup on a strat. I don't see how you'd get the hum cancellation by mounting a coil in the control cavity. Maybe I'm missing something. I read a page saying that the dummy coil is demagnetised too, but I assume that just means the core is much lower flux density rather than absolutely zero.
Way I think about it it has to be in the cavity to do its job without changing the sound too much. It is about having too coils with the same hum so they can cancell it out, right? But I only want the hum from that extra coil, no other stuff chaning the sound when you add those together. Thus putting it under the strings seems defeating part of the purpose. I would guess that parallel still makes sense though in that magnetic fields or so might effect them in the same way.
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Well I see your point. I guess the dummy coil doesn't need to be magnetic at all, it just needs to act as an aerial which has noise induced into it from external sources in an out of phase direction to the noise in the real P90's. If the coil is totally demagnetised then it wouldn't effect the sound as it would have no magnetic field at all. That said, it's interesting that gibson mount the coil under the strings... maybe someone got it wrong? If that is the case... how does it work if you mount the coil in a shielded cavity because then it would be theoretically isolated from any noise wouldn't it?
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Yeah, now you really got me confused. I was mostly guessing before and trying to make sense of what people do...now you got me thinking...and it hurts xD
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See! haha.
Now... how to make it work if your P90 set has has a RWRP pickup, because the dummy coil would end up creating noise which is IN phase with one pickup... right? Maybe I'm wrong again.
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Philking tried some hum-cancelling P90s in his WezV SG. I tried said guitar also. They sounded sadly sterile. I forget which brand they were, but it was a boutique brand of some sort.
Don't P100s sound quite sterile too?
P100s sound absolutely rubbish.
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I just temporarily wired in a spare Ibanez SC i had in parallel with my P90 and stuffed it in the control cavity (just needs to be on same horizontal to the P90 to 'buck' the same interference.)
Amazing trick - hum 90% gone and no real impact on tone as it does not add any signal.
I am frankly amazed... So I am going to solder it in permanently via a push/push so i can switch it out for the non Hi-Gain stuff.
Def. recommended to try. Fyi. My control cavity is not shielded so i suspect a shielded cavity could prevent it working same.
I could imagine a market for nice potted magnet free dummy coils to supplement classic P90s for high gain use.
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guitarteach:
thats pretty interesting - so to be 100% sure, you used basically a strat sized coil to cancel hum from a P90?
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Yep. I have not checked resistance and inductance though for a mathematically correct fix - but testing it wired in parallel it seems to have worked. It was an Ibanez Inf SC
Its basically an inverse aerial to kill noise that does not generate any additional musical signal from the strings.
I am sure there are better options but I was not considering changing my P90s as they would still be noisy - so i was intrigued to test this. Now i can see options to have high gain switch to kill the hum as I would not want to compromise the great low gain sounds.
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These dummy coils are very cool, but they seem quite invasive. Maybe I would try an Electro Harmonix 'Hum Debugger' pedal first.
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The Boss NS-2, which is often criticised for its performance in effects loops, did a decent job for me for dealing with Single coild noise/hum/feedback when I had a Strat.
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The Boss NS-2, which is often criticised for its performance in effects loops, did a decent job for me for dealing with Single coild noise/hum/feedback when I had a Strat.
Did you have the pedal in front of your amp?
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Well, I can say two things after a decent play with it today. (1) It doesn't sound any worse; (2) though it's hard to tell as the shielding didn't put the slightest dent in the screeching feedback and my ears are ringing again.
The issue isn't hum per se, it's the fact that every noise the guitar makes - hum included - feeds back like crazy under high gain. If I can find a way to stop hum theoretically that might eliminate the feedback that I can't control by muting the strings.
I'm thinking of trying the Hum Debugger even though people say that it affects tone. TBH I can't hear such small differences in tone over screeching feedback!
I'm more worried about the impact on my wallet ...
What does a microphonic noise sound like? I'm not sure if I've ever heard it or not. I do know that the guitar is very resonant and the pickup picks up every tap, knock, or turn of a screw
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If its screeching under high gain its still 95% sure the pickup is microphonic.
Does it stop when you turn the guitar volume down?
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I've just sent an email to Ben. This guitar is threatening to do my ears in. They are still ringing!
Possible its microphonic but I'm pretty sure I got some wax out of the pole piece screws when I turned them before, so I think it was potted. Question is I guess whether there's some kind of air pocket in the wax.
Also it uses the 'batwing mount' (you might be able to see that in one of the photos) so it mounts to the pickguard like a regular humbucker does in a batwing SG but I did put foam under it this time.
My SG Standard (Cold Sweat set) is quiet as a mouse in this respect and it has NO shielding. The Explorer (Nailbomb set) has shielded cavities - but no wired ground for the shield, so the shield is technically not quite as good as the one in the Junior - and it feedsback very little, like when you stand a couple of feet from the amp. The Junior squeals when you are in the same room. Some who like to exaggerate would say 'in the same postcode' ... it does it at least as far as my 20ft cable can reach around the various corners etc, I'd say at least 15'
EDIT:
I just realized that there was no photo of the pickup mounting in this thread so here's an old photo from when I first installed the BKP, which shows the new pickup mounted to the pickguard.
(http://i.imgur.com/lG5EpIU.jpg)
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OK. I think I've worked out what it might be, and it's a design issue with BKP P-90s that affects all who attempt to use it in a 'batwing' (full pickguard) SG with this type of mount.
The BKP P-90s have a pair of what looks like rivets on the back of their baseplates where two screws fit into the factory pickup that go through a block and hold the 'batwing' mounting plate in place. I had forgotten about this but when I first installed the pickup I had to leave the block and those two screws out, so that the pickup is mounted only by a pair of threaded bolts and nuts through the holes that normally use the long screws that in most soapbar P-90s are then screwed into the wood of the guitar.
To fix this it would involve sending the pickup back to BKP and at the very least removing the magnet and ensuring that it has the correct screw threads in place, and then sending it back to me.
I haven't heard back from Ben yet.
You can see what I mean if you look at the photos below.
The BKP (sorry the black rivets didn't turn out that well in the flash photos):
(http://i.imgur.com/BcByV6l.jpg)
(http://i.imgur.com/boeWFTK.jpg)
My stock pickup and the mounting system:
(http://i.imgur.com/pX3KjxN.jpg)
(http://i.imgur.com/i9a1Niu.jpg)
(http://i.imgur.com/CRQFUoS.jpg)
(http://i.imgur.com/NPPo7OC.jpg)
(http://i.imgur.com/57K0Tv8.jpg)
(http://i.imgur.com/xQr0QNL.jpg)
EDIT:
I think I might have the guitar modified so that the pickup screws straight into the wood. It will leave me with two adjustment holes in the pickguard but I plan to replace that discoloured pickguard anyway. That form of attachment will give a much more solid connection. Here's Jason Lollar installing a P-90 in an SG, and he discusses the batwing plate issue.
https://www.youtube.com/watch?v=AjOKO6D5puA&list=RDAjOKO6D5puA#t=1 (https://www.youtube.com/watch?v=AjOKO6D5puA&list=RDAjOKO6D5puA#t=1)
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Very interesting update, I've learnt something. Lets hope you've found the problem. Microphonic pickups are no fun.
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Why didn't you order a dogear mount? that would work fine for your guitar, and you could still put the soapbar cover on.
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I just ordered what I thought I had in the guitar, a regular soapbar.
The BKP soapbar would have fit okay had it not been for those two black rivets.
I think that a screw mount into wood as in that Lollar video will be best. I'll get that done when I have the nut and bridge installed. Until then I'll keep using the Nailbomb Explorer. i don't really need a backup at the moment as we are not gigging.
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Seems like we've gone back to March in terms of posts.
I think I added some since these, saying that I've had the pickup mounting converted over to a conventional screw-into-wood P-90 mounting and all of the feedback problems were sorted out by that move.
I also use less gain than I used to. The overdrive pedals are now used only occasionally for effect, with the pre setting on the lead channel of my Peavey 6534+ no higher than 12 o'clock (5)
The Junior is with Pete Jenkins again at the moment; he's fitting a set of Grover self-locking tuners to it and giving it another set up as the neck went out when I changed from Beefy Slinky stringss to Skinny Top Heavy Bottom strings. Also when I took all of the strings off to clean the guitar I jolted it slightly and the magnetic 'auto-lock' bridge fell off, so that went out of whack.
I'll post a photo of it with the Grovers next week when I get it back. I had to change a string on my Explorer at band practice last week and it took roughly 30 seconds with the Grovers, so I'm keen to have them on the Junior as well.
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Got it back from Pete tonight; here are some photos.
For anyone contemplating changing to these Grover tuners, be warned that they are heavier than the Gibson units. I have now got a bit of an issue with 'droop', but not too bad. I do need to hold it up though. If anyone has any suggestions - a weight in the control cavity? - I'm happy to hear it. I thought the weightier bridge might compensate, and it probably has done so a bit, but not enough to avoid droop
The original screw holes have been filled; the upper ones with mahogany wood putty, the lower ones with dowels (because that is a structural issue being close to the new holes).
(http://i.imgur.com/KNCckSN.jpg)
(http://i.imgur.com/aJLIfcA.jpg)
(http://i.imgur.com/ySj20MQ.jpg)
(http://i.imgur.com/vtINmcX.jpg)
(http://i.imgur.com/TZYkhfe.jpg)
This one shows the GraphTech ResoMax string-saver bridge and the change of the pickup mount from the 'batwing' (using the holes either side of the pickup) to a conventional screw-into-wood mounting with foam under the pickup. This did not require any kind of shim. The bottom of the cavity was high enough. A GraphTech TUSQ XL nut was also fitted. Strings are now an Ernie Ball Skinny Top Heavy Bottom set.
(http://i.imgur.com/8VYEG40.jpg)
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Grovers are really bulky, heavy tuners, unfortunately.
You could try replacing the metal buttons with plastic, pearl or ebony ones, that saves a few ounces. I'm not sure if they're available for Grovers, though, I've only bought them for Gotohs and Schallers.
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It's an issue with all of the variants of the Epiphone G-400 (including the Iommi model) that have Grovers; I suspect it is an issue on the Gibson Townsend sig SGs as well. The relative lack of hardware on the single pickup body might make it more of an issue; that's why I was wondering if I should put a weight in the rear of the pickup cavity. I really don't want to add weight though. I can probably live with a bit of droop.
It's certainly not in the category of the Epiphone EB-3 long scale SG body basses. The droop on those things is ridiculous: it's total neck dive.
By the way, as I think the thread on my Squier Vintage Modified '70s Jazz seems to have disappeared, that does not have any dive or droop but will soon receive a set of Seymour Duncan Quarter Pound pickups. They were only $138 delivered to Australia (new from an ebay seller), and I don't think I want the vintage sound of the two BKP Jazz bass models. I'm sure they'll do the trick. They are the most recommended Jazz pickups for hardcore and metal styles
EDIT: I guess I could try these: http://www.wdmusic.com/grover_mandolinbutton_white_gx1038i.html
They would look similar to the originals and the plastic would reduce the weight, while retaining the locking functionality
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The acrylic tuner buttons I eventually went with were the following direct replacements for the Grover kidney shaped buttons:
(http://i.imgur.com/QgDYpMH.jpg)
(http://i.imgur.com/yoyRgAB.jpg)
(http://i.imgur.com/ThxsElW.jpg)
They have really reduced the weight a lot and are more in keeping with the style of the original buttons while still looking 'hot rodded'
I bought them from an ebay seller in Taiwan, tiasamlu. http://www.ebay.com.au/itm/160947193050
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They have really reduced the weight a lot and are more in keeping with the style of the original buttons while still looking 'hot rodded'
I did the same thing on a Hamer Special I have and I was surprised how much of a difference it made. Really like what you've done to your SG; great set of upgrades.
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They have really reduced the weight a lot and are more in keeping with the style of the original buttons while still looking 'hot rodded'
I did the same thing on a Hamer Special I have and I was surprised how much of a difference it made. Really like what you've done to your SG; great set of upgrades.
Yeah, fitting lightweight tuner buttons is a good mod. I did the same on a Hamer Eclipse and on a Fender '90s Tele Thinline which was ludicrously unbalanced with the modern sealed Fender/Schaller tuners - it wasn't just neck-heavy, the headstock would simultaneously plunge towards the floor and try to swing the guitar around my back.... the bi-flex trussrod can't have helped, bad idea on a Thinline.
Generally, though, I prefer the vintage Kluson-style tuners which are nice and light in the first place.
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Really like what you've done to your SG; great set of upgrades.
Cheers. I really like it the way it is today with the heavy headstock issue sorted, although I could probably add a tiny bit of weight in the cavity to get it to the point where it is as well-balanced as it was when I bought it. I certainly wouldn't need much; the way it was with the metal buttons I would have needed a big bag of buckshot in there.