Bare Knuckle Pickups Forum
Forum Ringside => Tech => Topic started by: Shag101 on April 06, 2011, 11:54:40 PM
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Hey Guys,
I recently installed a MQ bridge replacing a warpig. I have a MQ in the neck as well. Gibson SG.
Im getting what seems to be 60 cycle hum from both pickups ( i think that is what it is)
When i touch the strings or any other metal part of the guitar..including pots and jacks...the noise does NOT get louder or lower. It is just constant and will only increase when i move the guitar near my laptop, amplifier, or increase the gain on the amp.
The noise also does not change in any way from neck, neck/bridge, bridge positions.
I know 60 cycle hum is normal with single coils but i never had it this bad with the queen neck..now i do. The only thing i changed from the neck wiring is move cap from modern to vintage and upgrade cap from ceramic to orange drop.
The hum is high pitched and lessens when i roll back the tone control on the guitar.
With gain, it is crazy loud.
The amp is a VHT special 6 combo. Tone knob on middle and volume up 1/4. No gain....and hum is pretty bad.
Is there some tests I can do to see if i do have a wiring issue? can i wire one pup directly to the input to see if the noise is still there? i have a multimeter if that helps.
thanks in advance!
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this is just general p90 hum
You'll be getting it a lot more on the bridge as its higher output.
its the only thing i dislike about my MQ.
A noisegate should help you
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you didn't have the hum originally at the neck? but now you do?
and you only replaced the bridge pup?
So you should have only been soldering around the bridge volume pot apart from moving the cap between the middle and outer lug on the neck vol pot?
sometimes in these cases it's worth posting a picture. The only thing I can think of is a disturbed ground or maybe a bad joint.
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Hey Guys,
I recently installed a MQ bridge replacing a warpig. I have a MQ in the neck as well. Gibson SG.
Im getting what seems to be 60 cycle hum from both pickups ( i think that is what it is)
When i touch the strings or any other metal part of the guitar..including pots and jacks...the noise does NOT get louder or lower.
It appears that there is a missing ground in your guitar. All metal parts should be connected to ground. Take a good DMM, put a cable into the guitar output jack and check whether there is continuity between the cable ring and all the metal parts of the guitar (pot backs, bridge, strings).
Cheers Stephan
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Thanks Guys..
I did pick up some 22 gauge cloth wire to get free shipping last week..so since i have the day off tomorrow..i'm just going to rip out everything and rewire...
if i still have the issue..i will post up some pics...
i did not have this issue before when i just selected the queen in the neck prior to any mods.
thanks again...i'll keep you posted....
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Also make sure you don't have multiple path's to ground. Pick one pot to ground everything through.
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Hey All,
I re-wired the guitar and it is exactly the same. Maybe a little less... Below is a pic of the wiring (yes I suck at soldering) and a link to a short video I made displaying the hum vs volume. I'm guessing this is normal 60 cycle hum. Maybe since I went from modern to vintage and noticed an increase in the high end...i also got an increase in the hum??? I used alligator clips so i was not paying attention to hum as i just related it to the clips..When all knobs were at 10, i noticed vintage had way more high end than modern..even though they should have been the same.
http://ge.tt/5cRBB8J
Again..Thanks for any input!
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I can't quite make out the switch wiring.
I guess the top middle lug is ground, and wired to the top of both volume pots, and the bottom with both contacts pushed together is wired to the output.
Originally, was this full of braided shield wire?
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yea, when wiring it dawned on me that i should have got 2 colors of cloth wire.
the hot terminal on the output jack was the center of a braided wire (like pups)..it went from there to the bottom of the switch where both pegs are pushed together. The braided part of the wire went from the ground terminal of the output jack..then soldered to 3 pots. The 3rd pots was then wired with regular 22 gauge pvc wire to the center pegs of switch...then to the last pot (4th pot).
This was the stock wiring from gibson and I still had the same hum...(though not as loud as prior to cap move)...moved cap and have same hum braided or non braided..or maybe just coincidence
I wired it basically the same as stock..but did not use the braided...
The hot terminal of the output jack goes to the bottom of the switch (both pegs still pushed together). The ground is a single uncut wire going from the ground of the output jack to a) bridge tone b)bridge volume c) top center pegs of switch d) neck volume e) neck tone. In that specific order..I used a GB cutter to access the wire without actually cutting it...
The guitar ground is soldered to the neck volume pot.
The cavity has some grey paint in it, so i'm guessing its painted shielding...
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Thanks St James, I might take you up on that offer if I cant figure it out. I live in queens, just a hop skip to nyc... :D
I used my multimeter on ohms as a continuity tester. I get anywhere from 0.2 - 0.5 readings. No open ckt here. Readings were taken between then output jack to the switch, pots, ground wire, bridge, stings, tuning pegs.
no loss in volume and the tone is HEAVEN!!!
i notice if headstock is pointed at amp..hum gets louder. if pups face the ceiling hum gets louder....i guess that is due to how the fields of the amp and pups are crossing each other. One way the fields are going in same direction and the other they are cutting into each other more so more hum...(prolly just talking out my butt here..lol..)
im guessing this is just the nature of the beast.
did you look at my clip and can tell its not normal hum??
thanks
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sounds like its all good? your wiring looked right to me.
continue playing NYHC.
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isn't a standard tone pot wired as a treble bleed? in which case there are two in the photo he attached.
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I don't understand what the treble bleed is you mean. sorry.
Do you mean when you put a resistor and cap from the volume pot input to the wiper?
I wouldn't really call that a bleed. It's more like a bypass. Those aren't in the photo either.
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thanks for the documentation St.James. i will give them a read..
so here is the deal...something must have changed in my living room because i just done what i should have done in the beginning. I went to the other side of the house and plugged up. The hum is considerably less and is how i remember it. :oops:
i appreciate everyones time on this.!!!
one last question.........would shielding the guitar make any difference or does the metal housing of the pups do a good job of that as is and it wont matter?
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I think this has been talked about before.
The metal covers should be enough.
adding shielding under the pickups is a source of conversation on the effects of metals in close proximity to the pickups magnetic field. some claim it stiffles the sound from the pup, however I have shielding the pup cavities on my les paul, although it has open coils, and I have no such problem.
Shielding the control cavity seems to be accepted as a nice move. Maybe it makes more difference if you use single core push back wire, since I use braided shield most of the time, there aren't any long lengths of unshielded wire in my guitars anyway. My charvel has no cavity shielding and is as quiet as my les paul. both use braided shield wire.
I'd imagine it might help a little, but the pickups/amp proximity issue probably won't be effected, and I doubt it would effect mains hum getting from your wall into your amplifier power supply.
other may know more. but thats my take on it
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cool, thats what i was thinking.
If i put the cavity in front of the amp, the hiss does not get louder so i'm guessing it will be a waste of time..
thanks again for the assistance everyone.....
Anyone reading this that might be thrown off by the hum i'm talking about...don't pass these up just for that if interested in a P-90..
I do think the MQ's are still the best pickups i've ever played...
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Sounds like what I was offering to help your figure out ....You were on a heavily used circuit that created DIRTY NOISE within the circuit you were plugged into.
The BEST WAY to fix that permanently is to run two designated circuits one for your amp and one for your 9 volt source.
Just wanted to mentioned this can hard if you're in an apartment block for example and you don't know the state of the building wiring. Say you have an air con unit on and that and everything else comes off one small ring. That is inviting noise. Some places are just prone to having noisy mains. Circuits with motors attached to them are the worst. Staying away from PC's is a good bet too.
The also sell niose reduction applications but they are basically censoring the noise NOT eliminating it
You could use something like an ICP decimater to gate out your guitar when you're not playing. Or something similar. But if it sounds good now then I wouldn't worry.
If ya want to really bring out your tone to where you can do TONE SWIRLS replace that cheap .022mf plastic capacitor with a.044 mf ORANGE DROP, VITAMIN Q, GREY TIGER, or BUMBLE BEE and your tone will be 10 times better !!!!
He already has Orange Drops in the guitar, and the cheaper ones are usually Ceramic Disc. What is a Tone Swirl?
If you have a drop off in yur mids and highs when you lower your Volume you can out a very inexpensive (1-2 bucks) treble bleeder in and it holds mids n highs and let;s them disepate slowly and evenly...making you tone more even and have it fade equally.
I tried this once and didn't like it. the treble bleed mod is this (below)... It works because the cap and resistor work as an RC Filter. Letting frequencies above a certain point bypass the volume pot. VERY similar to a bright cap you might find on an amps gain control.
The trouble is, with anything like a bright cap done in this way, the effect is dependent on exactly where your volume control is set. this is also true on an amp, bright caps don't work all the time because the resistive value in the RC Filter changes as you move the dial, thus changing the frequency response of the circuit. In the picture below. The cap is letting high frequencies bypass the pot, and the resistor in parallel with the pot (input and output) is effecting the value of the pot seen by the signal. So if you had your pot was turned to have a value of 100K, the total resistance seen by the input would be 50K. If your pot was on 500K, total resistance would be 83.333K
I found that it just made rolling off volume create a tone that was too bright from my guitar.
(http://www.tremolo.pl/Przystawki2/Modyfikacje_i_ciekawostki/treble-bleed_mod%20104.jpg)
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P90 style, they all tend to hum