Excessive noise with humbucker

[DavidLay]

I just got Full Shred humbuckers to replace a couple of EMG HZ pickups in a guitar I got earlier this year. The bridge pickup arrived before the neck pickup did, and I assume that one will arrive sometime today or tomorrow. I installed it as the diagram suggested, connecting the black wire to the switch, the red and white wires together and the green and bare are grounded to the volume pot. However, when testing the pickup out, albeit with only one string, there is more hum with the distortion on than there should be. I get less 60 cycle hum with the Invaders I installed in my ESP Horizon, which are supposed to be louder pickups, the EMG HZ pickups that were in this guitar before I threw in the full shred or even the cheap generic humbuckers in my 7 string Squier. I'm not sure why this is considering that I wired everything correctly. The only things I can think of are that the Full Shred is noisier because it has alnico magnets, and the H4A the guitar came with had more hum than the H4. It originally came with a H4 in the bridge and a H4A in the neck. I tried switching them around because I didn't like the rhythm tone of the H4 but found that the excessive hum with the H4A moved to the bridge position along with it when I swapped pickups so I wonder if there is a chance alnico magnet pickups just generate more noise than ceramic. The only other possibility that I could think of was that the neck pickup slot is currently empty and the H4A harness yolk was desoldered this morning so that empty cavity could be a suspect. The last reason I could think of was that there is only one string on the guitar right now so that I have less work to do when I get the neck pickup. I know these sound absurd and just made up, but I can't think of any other reasons why my full shred would make this much noise. Any ideas on why this is and how I can fix it?

[Zhangliqun]

Alnico is no noisier than ceramic. One string on the guitar vs. 6 won't cause more hum. The absence of a neck pickup won't either. It sounds like the pickup is wired in right by your description so chances are there's a problem somewhere else in the circuit. You may have jacked something up when removing the H4's. If that's the case, whatever it is, it's easily fixed, just have to hunt it down.

The only other thing I can think of at the moment is the bare wire has come loose from the Shred's baseplate or was never soldered to the baseplate to begin with. Pull that tape off and have a look. Or maybe the bridge ground has popped loose, by which I mean the wire that connects the bridge and strings to ground. If the hum stops when you touch the string, that's probably it.

[DavidLay]

I just unwrapped the tape and unscrewed the bobbins from the baseplate. The bare wire was definitely soldered to it. It didn't look like anything was amiss inside the control cavity but perhaps I should examine it again more closely. It has about as much hum as a single coil strat type pickup, maybe a little less. I used 60% tin 40% lead solder to wire it. The only thing I can think of left to try is just melting all of the solder on the things grounded to the volume pot and see if it solidifying fixes anything, or maybe moving the green and bare wires to a different part of the volume pot. Maybe there is a cold solder joint on the ground area. Tonewise everything sounds fine, I get a good output and the overall sound is good.

UPDATE1: The neck pickup just arrived. I'm going to try soldering that one in and see if it's any quieter than the bridge pickup.

UPDATE2: The neck pickup is now in. It also has the hum when the distortion is on. It has slightly less hum than the bridge pickup, but not by much. The hum disappears when both pickups are on at the same time. I'm not sure what it is although having google searched it, some people have said that alnico magnets tend to pick up more noise interference than ceramic magnets since they are technically a metal. Similarly, the H4A pickup that came with the guitar (the alnico version of the H4) had considerably more hum than the H4 pickup did, regardless of which position it was in, using the same presoldered quick connect yolks that came with the pickups. Has anyone else noticed extra hum with alnico humbuckers that was not present with ceramic ones? Nothing seemed to be wrong inside the control cavity so I really don't know what else to do at this point other than get a noise gate pedal. The hum isn't too bad, maybe slightly less than a single coil type pickup, but not by much.

[DavidLay]

I just found another topic on these forums after google searching and apparently some people have noticed more hum with alnico humbuckers than with ceramic although some have not. I don't know if anyone else has noticed this but here's a link. http://www.seymourduncan.com/forum/s...ead.php?t=1124

[DarkMatter]

Were the old pickups active?

[dudesta559]

Were the old pickups active?

He said they were emg hz and Those are active pickups. Still not sure which I like better. Active or passive

[DarkMatter]

Not familiar with the EMG lineup, I thought they made some passives as well.

But if that's the case don't active setups not use a bridge ground?
Maybe add that if so.

[DavidLay]

The old pickups were EMG HZ pickups, which is EMG's passive line. I didn't care much for the tone so I bagged a couple of full shreds and completed the swap today. I like the tone of the full shreds and the overall output a lot, but I don't much care for the extra hum. The EMG H4A had a similar hum while the EMG H4 was pretty quiet. The H4A is the alnico version of the ceramic H4. The guitar came with a H4 in the bridge position and a H4A in the neck position. They also had 4 conductor wire, although they had the quick connect yolk which made switching them back and forth pretty easy. The bridge of this guitar is also grounded.

[Grindspine]

Hum could be caused by improper grounding in the guitar, lack of shielding, poor quality guitar cables...

You need to go through the signal chain piece by piece and find the culprit. Do you have access to a camera to take a picture of your guitar's control cavity wiring?

[DavidLay]

The cables, pedals and amp are all the exact same ones so it's either something in the guitar or just the pickups are naturally a little noisy. I can snap a pic of the inside of the control cavity. Everything should be good as far as I know since nothing has changed since the removal of the EMG HZ's, and even then the H4A had a hum that the H4 did not, regardless of position. Plus the PSU's for my pedals are plugged into power strips in the same room. I will snap a shot and add it shortly.

[DavidLay]

And to update, here's a picture of the control cavity wiring.

[tonello]

I'm not sure. I thought for sure it was the grounding on the baseplate, but if you said that it wasn't, then I don't know. I always have someone else double check the wiring, because I probably won't see the problem, and with the picture of the control cavity, I don't see the problem yet.

I can see this being one of two problems:

1. It could be something wrong with wires inside the shielding of the pickup. I wouldn't know how to fix that, only that a technician should probably check the wires if you feel that it's that.

2. It could be that the amount of gain from the pickups and the distortion pedal is causing the extra noise. That happens with extremely high amounts of gain, such that it's manifesting as an excessive hum. A noise gate (I recommend the MXR Smart Gate) should clean the sound right up.

[RayBarbeeMusic]

The pots are 500ks, not the 25ks EMG uses right?

Does the hum go away when you touch the strings? Have you actually checked for continuity between the bridge and the ground of a chord coming out of the guitar with a VOM? Don't just look at it, test it.

Looking at your picture, those pots don't look like they share any ground other than the conductive cavity paint, which has surprisingly high resistance. Run a ground wire from the body of the volume pot to the body of the tone pot. Then make sure your switch is grounded. Then get a VOM and test resistance between the bridge, switch, tone pot body, and volume pot body. It should be 0 ohms or depending on how accurate your meter is, a fraction of an ohm. Then plug a short cable into the guitar and test for resistance between the ground of the chord and all of the above.

[DavidLay]

Yes, these are 500K Cor-Tek pots. The hum is still there when I touch the strings and it's about the same level as the alnico H4A that was in the neck position before. The ceramic H4 in the bridge was pretty quiet. All my guitars were tested through the same setup. There is a ground wire connecting all of those parts. It's the big green wire connecting the two pots I believe, and there's a black one going to the switch and another black one going to the bridge. The humming is slightly less than that of a single coil pickup.

[Fusion1]

What would make the noise disappear once he has both pickups active? This has me stumped as it doesn't sound like a grounding issue like I figured this would turn out to be.

[DavidLay]

I'm just as surprised. The only thing I can think of is the alnico magnets maybe being a little more noisy and possibly both pickups being active causes enough cancellation to remove the hum entirely. As a way of double checking, I touched a screwdriver to all 4 bobbins while each pickup was active to see if I could hear a click from the amp and all 4 clicked so I know they're all working. The bridge pickup was a brand new full shred while the neck pickup was a used full shred found on ebay with little use on it.

[RayBarbeeMusic]

The hum is still there when I touch the strings

And it is only slightly less than a single coil? Something is wrong, those pickups do not hum like that normally. Unfortunately, if you checked everything I told you with a VOM and got good results, I'd have to see it in person to go any further.

[AlexR]

?ground loop

[DavidLay]

I think I've already ruled out ground loops. I filmed a video demonstrating the EMG pickups before removing them. The alnico pickup had the same hum to it that the ceramic one did not. I did this with the intent of demonstrating that the pickups work, which I intend to embed in the upcoming ebay listing for them. I will post a link to that here once I have it uploaded. Note that in the case of the EMG pickups, it was definitely in the pickup since when I switched them around using the quick connect harnesses without having to resolder anything, the hum was always with the alnico pickup, regardless of position.

[DavidLay]

Sorry this took longer than planned. Anyways, here is the video I did to demo these pickups. The pickups make a little more noise in the beginning because I'm kneeling and because my car's keychain remote is in my pocket, which I later remove and also start standing up. The full shreds have about as much hum as the neck pickup in this video, which is the H4A. I get a little carried away and riff around a bit but I think the basic point is made. I'm going to do another video comparing the hum levels and tone qualities of the pickups on my other guitars sometime soon as well.


EDIT: Either I'm not using the youtube tags correctly or the embed function is not working. For the time being, here's a link to the video. http://www.youtube.com/watch?v=zZzzGghMbgQ