Weird grund noise on humbucker

[Biarnel]

Hi all, it's me again.

I just wound a 5string bass humbucker with these specs:

2 coils
10mm dia. mags, one per string
1.5kOhm each coil
AWG 40 coil wire.
coils placed like this:
o o o o o
o o o o o
Pickup cavity and control cavity shielded and grounded, coils NOT shielded, in a single coil fashion
Strings not connected to ground, because I don't like to be electrocuted.

Having such a low impedance a preamp is obviously required.
Anyway, I'm testing it with a Mark Bass combo, Pickup directly in the amp, no tone or vol pots on board, no preamp.

Well, it's really sweet, apart being a bit too harsh with the highs all crancked up.
BUT!
When in single coil mode, I can hear the typical bzzzzzz of a single coil hum: I can get rid of that using the amp's tone controls.
When in humbucker (series) mode, I hear a continuos click-click-click-click...

...what the...?
Think to 2 clicks per second. More or less.
In hum canceling mode I should have the hum.. canceled! This is enhancing :-p !

Please help.. this is a new thing for me: never heard of a clicking humbucker.

[Rosewood]

Cell phones and watches out of the way?

[Joe Gwinn]

Hi all, it's me again.

I just wound a 5-string bass humbucker with these specs:
...
Pickup cavity and control cavity shielded and grounded, coils NOT shielded, in a single coil fashion. Having such a low impedance a preamp is obviously required.

BUT!
When in single coil mode, I can hear the typical bzzzzzz of a single coil hum: I can get rid of that using the amp's tone controls.

And better shielding.

When in humbucker (series) mode, I hear a continuous click-click-click-click...

...what the...?
Think to 2 clicks per second. More or less.
In hum canceling mode I should have the hum.. canceled! This is enhancing :-p !

Please help.. this is a new thing for me: never heard of a clicking humbucker.

Well, humbuckers buck hum. Their contract says nothing of clicks. You'll have to take it up with their union.

Seriously, humbuckers cancel the uniform fields from distant hum sources. The fields from nearby sources are not as uniform, and so will not cancel as well. Another poster suggested that the source might be a watch. This sounds like a possibility to me.

Strings not connected to ground, because I don't like to be electrocuted.

Well, it's a scare story to be sure, but the strings should be grounded. If one's amps are putting line voltage (220 volts in Europe) on the shields of the input cables, you have big trouble, and the guitar strings are the least of it. A better approach is to measure the voltage between cable shield and ground. If it's more than a volt, send amp in for immediate repair. The measurement can be as crude and cheap as a neon-tube voltage tester - if it lights up, stop using the amp immediately, as there is at least ~50 volts between the shield and ground.

More than likely, such an amp will also hum badly, but one cannot depend on this.

[David Schwab]

Pickup cavity and control cavity shielded and grounded, coils NOT shielded, in a single coil fashion

That's problem number one. Shield the pickup. Even open coil guitar humbuckers have a metal base plate which serves as a ground plane.

Strings not connected to ground, because I don't like to be electrocuted.

That's problem number two. I managed to have a quiet bass without string grounding, but everything was very well shielded, including the pickups. When I used EMG's I didn't ground my strings, but if you check the photos I posted of an EMG SA I dissected, you can see that it's totally shielded. Do the cap and resistor trick if you are worried about shocks.

As a side note, I've been playing bass since I was about 10, and I'll be 50 next month. I've been playing out in clubs since I was 16 (I looked older) and I've only gotten one bad shock, and that was in my basement! Then I started carrying a neon outlet tester... I'd touch it from my strings to the mic, if it lit up, I needed to address a ground issue. Now I use a pocket VOM.

Having such a low impedance a preamp is obviously required.
Anyway, I'm testing it with a Mark Bass combo, Pickup directly in the amp, no tone or vol pots on board, no preamp.

I often test low Z pickups by plugging them into my Behringer mixer and cranking the mic pre... but you may get extra noise that way due to the high gain. An onboard preamp is closer to the pickup, so its a bit quieter. Also you will get better high end with the preamp, and you wont have to crank the highs on the amp. Some of my pickups are about the same DC resistance as yours. Did you wire them in series? They sound much better that way IMO.

How do you like that MarkBass? I really want to try one out. Jeff Berlin got a great tone when I saw him play.

Well, it's really sweet, apart being a bit too harsh with the highs all crancked up.
BUT! When in single coil mode, I can hear the typical bzzzzzz of a single coil hum: I can get rid of that using the amp's tone controls.
When in humbucker (series) mode, I hear a continuos click-click-click-click...

You have a watch on? You are picking up something and it sounds like a watch. I used to hold my watch by the pickups all the time to hear it click. Cell phones make weird galloping noises too.

Back to problem number one... lack of shielding.

[David Schwab]

Well, it's a scare story to be sure, but the strings should be grounded. If one's amps are putting line voltage (220 volts in Europe) on the shields of the input cables, you have big trouble, and the guitar strings are the least of it. A better approach is to measure the voltage between cable shield and ground. If it's more than a volt, send amp in for immediate repair. The measurement can be as crude and cheap as a neon-tube voltage tester - if it lights up, stop using the amp immediately, as there is at least ~50 volts between the shield and ground.

More than likely, such an amp will also hum badly, but one cannot depend on this.

I just read you also suggested a neon tester. I took a reading with my VOM once after the tester lit up, and it was 80 volts! Ouch!

It's not always your amp, its sometimes the other amp or PA system. People using those non grounded outlet adaptors to lift the ground and stuff like that. The other problem is miswired outlets. Either the ground is open, or they have the common and hot reversed. (of course this is for US mains... Euro mains confuse me!)

[Biarnel]

Well, just to be clearer.. I didn't wear a watch, nor there was a watch nearby.

Speaking of string grounding, I prefer not to ground strings for a couple of reasons: first of all, I really HATE when you touch the strings and the amp makes "bzzz-CLICK" and then you lift your hand fron the strings and the amp, again, "TICK-bzzzzz". Reason number two, there are a lot of players saying "whoa! this pickup is so quiet! listen, you can't hear the difference if you touch the strings or not!" :-p

I made several instruments without string grounding, and they are quiet: cavity shielding, pickup shielding, no string ground.

Will it be different if I put a metal base under the coils, to serve as a ground plane as David said? I did not wrap the coils in shielding material because I wanted the most HiFi (more or less..) sounding possible pickup. This is why I choose that low impedance.

By the way that pickup is really good in highs and lows, and so pure i can hear the fingerprints of my plucking hand thru the amp
..too bad for that clicking sound.

By the way, that periodic sound... what could it be?

[David Schwab]

Will it be different if I put a metal base under the coils, to serve as a ground plane as David said? I did not wrap the coils in shielding material because I wanted the most HiFi (more or less..) sounding possible pickup. This is why I choose that low impedance.

It might help a little... I doubt much though. You can tape around the coils, just don't close the loop. Leave a small gap, or insulate the end.

By the way that pickup is really good in highs and lows, and so pure i can hear the fingerprints of my plucking hand thru the amp
..too bad for that clicking sound.

By the way, that periodic sound... what could it be?

Yeah, that's how my pickups are. I swear I can hear the sound of the phenolic fingerboard on my basses. You can really get many different tones from just plucking the strings in different ways. I got so used to playing my bass unplugged, and getting a certain tone, then I wouldn't hear it in the amp. Now my bass sounds like it does unplugged, just with a lot of low end.

Your pickups are picking up something making a ticking noise. Does your amp do this on its own? Does it go away if you reposition the bass? Try moving to another room and trying it. It might even be the switching power supply in the amp, which you don't hear from the amp, but is getting picked up by the pickup. How far from the amp are you?

I think it will go away when you install a preamps and more shielding.

For shielding, I use closed covers. I line the covers with copper tape, which I then ground. I run a piece of tape around the the pickup from top to bottom (not around the coil) and that grounds the magnet/blades. When testing the pickups with no cover, touching that tape really stops any buzzing I'm getting.

[Biarnel]

Your pickups are picking up something making a ticking noise. Does your amp do this on its own? Does it go away if you reposition the bass? Try moving to another room and trying it.

It's not the amp: when I plug the bass in my USB M-Audio interface, with the signal going in my Mac, I got the same tick-tick-tick.
A clockwork bass.

By the way, the electrical wiring in my house is very well grounded: I usually go somewhere else to test my instruments for noise, because here at home they won't hiss/buzz even with no shielding

This is why I'm so puzzled with this tick tick.
By the way, how should I stop the single coil mode humming sound without cutting out high or low end?

Another question: why bother grounding mags, when I use closed wooden covers? Should I, anyway?

[David Schwab]

It's not the amp: when I plug the bass in my USB M-Audio interface, with the signal going in my Mac, I got the same tick-tick-tick.
A clockwork bass.

It can't be coming from the bass... are you sitting near your computer?

By the way, how should I stop the single coil mode humming sound without cutting out high or low end?

Except for shielding it, you can't. Why bother with single coil mode anyway? On my pickups, they don't sound much different in single coil, so except for extra noise I see no reason to use it.

Another question: why bother grounding mags, when I use closed wooden covers? Should I, anyway?

What's the covers have to do with it? If you get your hand over the cover, it will hum... you don't have to touch the magnet. You just have to get close.

Here's a set of small humbuckers that are going in wooden covers. You can see the ground strap around the pickup. The covers will be shielded on the inside also.

The second photo is how Duncan grounds the steel poles on a MM pickup.

Shielding and grounding will make your pickup quiet and wont mess with the tone.

[EtLa]

I hear a continuos click-click-click-click...

it's the hydraulic valve lifters... it's normal on old 350 chevrolet pickup engine

[TGD]

Biarnel, clicking effect can happen when electronics starts in auto-oscillation. Check around impedance mismatch.