Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, amp..

[doctadre]

Hey all,

I've been swapping pickups left and right on my SC245 and trying a couple Zhangbucker models I found used. I noticed at a recent show at a somewhat noisy venue that the guitar made MORE noise than normal, especially for a Humbucker.

I've been testing at my house. I normally didnt notice too much noise until I turn up volume to more gig-like levels. Now I'm doing tests and noticing the noise for sure.

Details:

Amp: Mesa Mark V 25 - great amp, high gain of course but I don't have the gain or volume too cranked. Gain maybe 1-2 o clock on Mark 4 mode, Volume barely around 8 o clock and it gets loud enough. I also compared with my regular Mark V, same noise. Still, not sure if something in my house wiring could be causing. Bad ground, receptacle, etc. Going to get an Ebtech ground hum device to try and eliminate this cause. May also look at tubes, but I have farily new tubes in there.

Guitar - The Zhangbucker bridge is a little worse than neck. 10k bridge, Alnico 8. Humbuckers shouldn't have too much noise, this one sounds similar to 60 Hz hum. When I split the coil the noise gets worse of course.

I've tried other guitars to compare to, I've done wiring on both, so can't tell if it is my bad wiring. There is some noise on the other guitars, but its a little bit lower, so I must have done something wrong in the SC245 wiring perhaps.

One of my guitars actually has Seymour Duncan Phat Cats, and their middle position which is hum cancelling actually has the lowest noise of all guitars, which is also weird.

The humbuckers in most of my guitars are mismatched a little. Not sure if this adds noise. The Duncan Custom on my Custom 24 is not mismatched and still has some noise. My other guitars have pretty good shielding in the cavity, paint around cavity and foil on cover plate.

Ground loop in wiring: I think it could be a ground loop in wiring, and will try to wire star position style, where all grounds go to central nut and then jack ground to that. Not sure it will help but I need to try.

What else could be going on? I have noticed noise at certain gigs due to TVs, lights, but never this bad. The SC245 has a higher level of noise. I'll try a pickup swap and grounding wiring. The cavity has conductive paint in it so I can also put foil on the plate and see if it helps, but I did some tests and don't think it will.

My only other solution is a noise gate, but I really feel like I can get the noise down, especially because its humbuckers we are talking about. I dont think my gain settings are too unreasonable.

Any advice or tips would be super greatly appreciated!!! Thanks guys!!


Dre

 

[dotsdad]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

Low 60 Hz hum is a grounding problem. Make sure all solder joints to ground are good.

High buzzing from TV or stage lights is EMI. The way to solve that is to shield the guitar cavities (and be sure to ground that too)

 

[Mincer]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

I would also try the guitar in a different building. Try it with a different amp in the same building. The goal is to figure out what is causing this.

 

[beaubrummels]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

Does it stop if you touch the strings? Did you leave off the bridge ground?

 

[doctadre]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

No, touching the bridge or strings does not change anything. I did solder the ground wire from bridge. It's tough to say whether ground loop or EMI, might be both really. I heard that ground loop noise can come at higher harmonics of 60 Hz too. Tomorrow I'll try to get a few sound clips of what I'm hearing and seeing.

I could try plugged in downstairs in the garage, see if the sound or noise changes. I definitely know I have less than ideal wiring in my house and some receptacles aren't great too. I may swap the pickup for another and see what that sounds like. During that swap I'll check the solder joints.

Should I try this star ground joint, or just connect all backs of pots together with a single wire and then connect one to jack ground? The latter is what I normally do. Never knew it could cause a problem until reading about it.

Do I need to shield the pickup cavities too? Guitar cavities are shielded but the covers are not. I'll foil them up.

Thanks!

Dre

 

[Darg1911]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

If touching the strings or bridge doesn't make a difference in noise level, I don't think shielding will help. You have another problem, ground related.

If you get that sorted out, my experience with shielding .... If the PRS isn't shielded and you still have hum/buzz after you get the grounding and wiring sorted out you may want to consider shielding it. If so, I've had just as good results with carbon based paint as I have with copper tape. The paint is easier to apply (and you don't end up bleeding). I do the control cavity, switch cavity and pickup cavities. I have not personally noticed any change in tone after shielding compared to the same guitar before shielding. Some claim that there can be a subtle change but I cant hear it. If that is a concern, use the tape. It's removable. My advise ... don't paint/shield the area of the circular cutout where the output jack resides. You could potentially end up with a short if the jack is a snug fit. Don't ask me how I know, just suffice it to say that sanding the conductive paint from that hole after the fact is a pain in the arse.

No guarantees that shielding is the fix because I think the source or type of noise determines how effective shielding is. And copper, carbon and aluminum are supposed to be better at different types of interference, not a one size fits all thing. All I know is that both copper and carbon paint have both worked just as well for me. REALLY well.

Just my personal experiences. I'm not a guitar tech or electronics wizard.

 

[doctadre]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

Thanks to all for the tips!! Here is an update of sorts:

Tried all of my guitars, going back and forth. Also tried my regular Mark V for comparison. Same noise levels on the Mark V.

All of my humbucker equipped guitars have a slight bit of hum in all positions, but the SC-245's level is just a tad higher, so I think I need to troubleshoot and check all solder joints for sure.

I tried the Mark V 25 in my garage, different outlet, cranked. The noise is still there (with SC245, didnt try all), and would reduce when I faced 90 degrees from amp. No noise when amp is on and unplugged input. Must be the guitar for sure.

These pickups had a split (or Splat for Zhangbuckers). The noise I hear in humbucker mode is a slightly quieter version of the single coil split mode, if that helps at all.

Zhangs are mismatched coils, so it could be from that, but I also popped in an SC250 bridge pickup and it has same noise levels.


The funniest thing so far is that the only guitar that was dead quiet was my PVX kit guitar with 2 Seymour Duncan Phat Cats in it. The middle position is so quiet, not one ounce of hum. Of course switching to either position alone is a loud single coil hum. Is that weird?

I figured humbuckers should be quieter. The gains I use aren't too crazy, but it is a high gain amp. Any thoughts? Do you guys have small amounts of noise in even humbuckers at high gain?

I have my cavities quite shielded as well.

I wired all of my guitars in some way, so it could be some bad solder, but I think the real issue is just the SC 245. I'll check that soon.

One other question. Should I always hear a difference when touching bridge/strings vs. when not? I noticed in some guitars, SC 245 included, that I dont hear that drastic change in tone when touching the bridge or other metal. Does that mean something is wrong with bridge wire to ground?


Thanks

Dre

 

[Mincer]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

You should hear a difference when you touch the bridge or strings vs not. At least with passive pickups. Have you tried the instrument in another building or room?

 

[Chistopher]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

There is one thing for certain, its not a ground loop. Ground loops can't occur in electric guitars. Explaining why is very complicated and I won't bother you with the full explanation here. Star wiring makes no difference over any other method of grounding the electronics.

As for my guesses towards your issue, I agree with the previous posters about a possible ground issue. There is a good chance that you have a cold solder joint some where. Another possibility is a bad pot is causing your issue. This would be tough to check for, but it's always a possibility, so if you can't find any other issues, I'd check the pots out.

There's also the ever-present chance that you have a bad cable that's responsible for a bit of noise across all your guitars.

 

[Clint 55]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

Humbuckers have noise when cranked.

 

[doctadre]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

I've gone through the wiring a bit and even checked the bridge pickup direct to the jack, still getting some type of noise. I'm beginning to believe that even with super high gain, humbuckers can make noise. My question is, this particular humbucker is noisier than others, which are all higher DC resistance and hotter pickups. This is a Zhangbucker Duane Plus with A8 vs Duncan Customs basically. The hotter pickups aren't as noisy. I wonder if it could be the Alnico 8 accentuating the high frequencies and making the noise more prominent. I have yet to check the ground solder on the 3 way switch in the upper bout. Will try tonight but other than that I've re-done the wiring enough to know I don't think it's that.


Dre

 

[Chistopher]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

I've never had an A8 increase noise in any pickups, noiseless or otherwise. I'm starting to think you might have a bad solder joint on the pickup itself.

 

[doctadre]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

I have checked all grounds with a multimeter too though. Seems like all is good there.

These pickups have some mismatch in the coils so that could also be it, but I'm still not fill convinced. I've also had a different pickup in there and had the same type of noise.

 

[beaubrummels]

Re: Help! Noisy guitar, humbucker. Can't tell if it is pickup, wiring, ground loop, a

Magnets don't add or accentuate noise IME. Wire and shielding can. Humbuckers with mismatched coils will have more hum because if the coils are not equal, they are not equally cancelling noise. But mismatched coils is for the improvement in tone, provided you can take care and avoid environments that increase noise, like having your amp on the same circuit as a light dimmer, bad unconditioned power, or near a transmisster/receiver of any sort, etc.