Is 60 cycle hum really that bad?

lowendpurveyor · #1 11-25-2009, 05:23 AM

Sorry for the newbieish question. I'm not actually sure what 60 cycle hum sounds like. I have a Jazz bass with 2 single coils, when I solo them both there is no hum as far as I can tell although theoretically they should hum. I haven't gigged with a single coil Jazz before so it might become more apparent in a loud live setting. The only hum I get is when I am near a TV when I take my hands off the strings.

In theory do both the neck and the bridge pickups have to be full on to completely eliminate any hum or can you have one pickup full on and dial in only a little bit of the other pickup to eliminate the hum completely? If the hum is so bad how did guys playing original old vintage instruments with the original pickups get clean sounds without the hum both on recordings and in a live setting? Is it worth replacing single coil pickups with their humcancelling counterparts and sacrifice the purity of a single coil tone?

**line6man** · #2 11-25-2009, 07:11 AM

It usually depends on your situation.
If you are playing near florescent lights or CRT monitors and stuff like that, it can be really bad, even unbearable, but in other situations, it can be almost silent.

If you are not sure what 60Hz hum sounds like, solo one of the pickups. You should quickly learn what it sounds like...

It's usually possible to just slightly favor one pickup and still cancel most of the hum, but you pretty much need both pickups to be equal in volume.
The way it works is, you have two equal waveforms (the noise) on opposite waveforms, so they cancel each other out. If you change the volume of one pickup, one of those waveforms has a greater amplitude than the other, so they are unable to cancel each other out.

dmusic148 · #3 11-25-2009, 07:16 AM

Quote:

Originally Posted by lowendpurveyor

In theory do both the neck and the bridge pickups have to be full on to completely eliminate any hum ....

No, they just need to be set equally, or nearly so. Even soloed, they won't always hum. Hum happens when you are near a hum source, such as a TV as you discovered. Or a neon sign. Or an electronic poker game. Or a jukebox. Or a bass or guitar amp, PA head, etc. Cell phones create interesting noises too, especially while in use.

BBKINGBASS · #4 11-25-2009, 07:27 AM

With my old MIM 99' Jazz bass, Fender had decided to not RW/RP one of the pickups, thus not giving you humcanceling. I didn't notice it until I had my first gig with the bass and with the stage lights I was getting some terrible hum. So the next day I bought new pickups for and solved the problem.

Like others have said, 60 cycle hum can be bad on the situation. Usually if your playing live you won't hear above the band its only inbetween songs and during quiet parts you may hear it.

SteveC · #5 11-25-2009, 07:29 AM

I think it is.

Jim Nazium · #6 11-25-2009, 07:34 AM

Nah. Just tune your A string to 60hz and play modal jazz all night.

Nedmundo · #7 11-25-2009, 07:37 AM

The amount of hum varies a lot among basses and guitars with single coils, as it depends on pickup design and shielding. On my Jazz basses, it's been brutal when the volumes aren't equal, unless I'm in an electronically quiet environment. I've gone to noiseless pickups on both, but will probably revert to the stock single coils on my 2008 Jazz V because they sound so darned good. I'll try shielding there.

My Strat wasn't as bad as the Jazz basses, and my DiPinto Belvedere bass with two single coils was amazingly quiet when soloing the pickups. I had no problem with it on stage, and it was bothersome only in the worst environments.

Some people will tolerate the hum for the pure single coil tone, while others won't. I'm somewhere in between. If it were always at the low level of the DiPinto, I wouldn't mind, but my Jazz basses are too much, and it's a problem because I like rolling off the bridge pickup about a third.

mongo2 · #8 11-25-2009, 07:53 AM

I've found that since the local clubs around here over the years have mostly switched from CRT TVs to LCD TVs that it's not nearly as much of an issue as it used to be.

Neon signs will up the noise though.

JTE · #9 11-25-2009, 09:50 AM

The 60 cycle hum is as big a problem as you find it to be. Sorry for the flippant response, but that's it. Are you doing professional master recordings? In that case, ANY RF or 60 Hz. noise is going to be a problem. Are you playing three songs at the local "were all original and soooooo cool none of the bands have more than four songs together" rock club? Probably not an issue at all. Is your bass being routed through a great PA? There's where it could be a real problem. Are you playing a quiet coffee house gig where all the other instruments are acoustic? Then the noise will stick out like Pamela Anderson at a gymnast's convention.

John

Lincoln · #10 11-25-2009, 12:22 PM

Can you still cancel the hum if you're running a coil cutter switch on soapbars and you have a volume blend pot rather than 2 separate volume pots?

CatfishStudios · #11 11-25-2009, 12:26 PM

Come jam at my wife's Uncles ungrounded 1914 home complete with vintage wiring and glass screw in fuses and play through his 68 Bassman head and 2-15 Sunn...you will know 60 cycle hum...oh you will know it well.

Philbiker · #12 11-25-2009, 01:34 PM

Quote:

Originally Posted by Jim Nazium

Nah. Just tune your A string to 60hz and play modal jazz all night.

Ell Oh Ell!!!

It's different in different situations. One of my favorite basses is a Jay Turser with a single coil pickup. Theoretically being cheap and single coil it should hum loud as hell, but in almost every situation I've ever been in the hum is barely noticeable.

JTE · #13 11-25-2009, 01:59 PM

Quote:

Originally Posted by Lincoln

Can you still cancel the hum if you're running a coil cutter switch on soapbars and you have a volume blend pot rather than 2 separate volume pots?

Well, the blend pot is no different to the circuit than two volume controls so that won't affect 60 Hz noise at all.

Now, "a coil cutter switch on soapbars" doesn't tell me anything. If the soapbars are configured as dual-coil humbuckers AND if by "coil-cutter" you mean that you short out and totally KILL one of the coils, then it would be a single-coil and still prone to buzz when soloed. However, if it's wired like the Barts MM PUP that Lakland uses it's still humbucking when in "single-coil" mode. That's because that PUP uses FOUR coils so each side is still fully humbucking.

If the "coil-cut" switch is a tap that merely shortens the number of turns active in the PUP it's still humbucking, but it would have to tap both coils at the same number or winds to be most effective.

John

**line6man** · #14 11-25-2009, 02:11 PM

Quote:

Originally Posted by JTE

Well, the blend pot is no different to the circuit than two volume controls so that won't affect 60 Hz noise at all.

Now, "a coil cutter switch on soapbars" doesn't tell me anything. If the soapbars are configured as dual-coil humbuckers AND if by "coil-cutter" you mean that you short out and totally KILL one of the coils, then it would be a single-coil and still prone to buzz when soloed. However, if it's wired like the Barts MM PUP that Lakland uses it's still humbucking when in "single-coil" mode. That's because that PUP uses FOUR coils so each side is still fully humbucking.

If the "coil-cut" switch is a tap that merely shortens the number of turns active in the PUP it's still humbucking, but it would have to tap both coils at the same number or winds to be most effective.

John

+1.

ex-tension · #15 11-25-2009, 06:20 PM

Well, it's a little bit off-topic detail but it says "Location: Australia" and the mains power there is 50Hz not 60.

**line6man** · #16 11-25-2009, 08:26 PM

Quote:

Originally Posted by ex-tension

Well, it's a little bit off-topic detail but it says "Location: Australia" and the mains power there is 50Hz not 60.

That's actually a good point.
If you live in Australia, then you don't know what 60Hz hum sounds like.

lowendpurveyor · #17 11-25-2009, 08:30 PM

Is there an equivalent? Say a 50 Hz hum?

**line6man** · #18 11-25-2009, 08:31 PM

Quote:

Originally Posted by lowendpurveyor

Is there an equivalent? Say a 50 Hz hum?

Yes.

You still get the same single coil hum, it's just at 50Hz instead of 60Hz.

bassbenj · #19 11-25-2009, 10:59 PM

Quote:

Originally Posted by lowendpurveyor

Sorry for the newbieish question. I'm not actually sure what 60 cycle hum sounds like. I have a Jazz bass with 2 single coils, when I solo them both there is no hum as far as I can tell although theoretically they should hum. I haven't gigged with a single coil Jazz before so it might become more apparent in a loud live setting. The only hum I get is when I am near a TV when I take my hands off the strings.

In theory do both the neck and the bridge pickups have to be full on to completely eliminate any hum or can you have one pickup full on and dial in only a little bit of the other pickup to eliminate the hum completely? If the hum is so bad how did guys playing original old vintage instruments with the original pickups get clean sounds without the hum both on recordings and in a live setting? Is it worth replacing single coil pickups with their humcancelling counterparts and sacrifice the purity of a single coil tone?

So many Questions! But here's what a noob needs to know.

First there are TWO kinds of hum. Electric hum and magnetic hum. Electric hum is eliminated by shielding the cavities in the bass. It is obvious by the fact that when you touch the strings or metal parts (jack nut) the hum goes away. That is a sure sign your bass is lacking shielding in some place.

Magnetic hum comes from transformers (The power transformer in my combo amp is a wonderful source, as are neon signs, TVs and the other things people have mentioned). Touching the strings or ground will NOT make it go away. On the other hand if you move the bass around in wild orientations usually you will find a position that makes the hum go away or at least minimizes it. (You are placing the hum field at right angles to the pickups so it's nulled out).

The hum that noobs find "goes away when I touch the strings" is the classic "your bass needs more shielding" hum. The hum you hear from soloing a Jazz pickup is the classic magnetic hum. The only cure for magnetic hum is to either remove the source of the hum field (move on stage, turn the neon sign off etc.) or to use humbucking pickups.

A Jazz bass shows how humbucking pickups work. One pickup is wound with magnets and coils with a certain polarity. The other pickup is wound with the opposite polarity on the coil (which would reverse the phase of the pickup so it wouldn't add properly to the first pickup) but then to get the phasing right the North and South poles of the magnets in the second pickup are reversed so that now both pickups reproduce the strings in proper phase, but the two coils are reversed with respect to each other as far as the hum field is concerned. Thus, if you set both pickups on and to the exact same volume levels, the hum pickup in one is exactly canceled by the hum field picked up by the other. Hence the term "humbucking". OK? If the settings are not exactly equal the hum will not be canceled out.

So how can you eliminate hum pickup in a single coil pickup? You almost can't! One solution is to use two pickups side by side (often called soapbar) Works nicely but does have a somewhat more muddy tone than single coils. Another is to place a second coil below a standard jazz pickup (called "stacked" humbucker) In my experience those also lose some clarity. A third method found in some older basses is to use a standard single coil pickup but place a simple coil of wire nearby. The coil has no magnets or pole pieces. It's only purpose is to pickup hum. Usually it's between the two pickups. I don't think many basses use this anymore.

And lastly there is the Fender "noiseless" pickups. My MIM Fender has them and yes they work! I'm not sure just what the "technology" in there is, but I suspect it has to do with stronger modern magnets plus a side by side coil arrangement like a P-bass but not offset. Just guessing.

So if hum while soloing your jazz drives you nuts Fender "noiseless pickups" are a great choice. And they are quite reasonably priced too.

That's about it for the noob hum story.

Steve · #20 11-26-2009, 09:01 AM

If you get in the wrong environment at the wrong time...yeah, 60 cycle hum can be brutal.

I frequently work a bar in "The Nations Oldest City" which has also, the nations oldest power grid. The power lines that run past the front of that venue are so overloaded that, on bad nights you can actually hear the wires crackle and hum if you stand underneath them. When they start doing that, there is nothing that will help except chopping high end. Even with HC pickups, if you push any high end at all, it's misery.

Under MOST conditions though single coil PU's with proper shielding shouldn't be a significant issue. Under any conditions it won't be as bad as your Strat playing guitard when he stomps on his crunch pedal.

I never could figure out why people freak out over a little noise in the bass when the guitar amp right next to it sounds like there's a Hornets nest in it.