Guild Reissue Rhythm Chief 1100 Hum

[Elkus]

Hey everyone, I'm new here. I've followed the page for years and have always found the answer needed through other people posts.

I installed a 1100 reissue, on my Loar lh700, complete with volume and tone pot. It is a dream...

I know single coils hum, but I've read mixed forums about this pickup. Some have hum some do not. Am I missing something or do they all actually hum...?

I am hesitant to take it apart again to re solder everything to find it still hums.

If I touch the tailpiece, end pin or strings the hum is gone.

Thank you, Elkus.

[sgosnell]

You need to make sure the strings are grounded through the tailpiece. You need a wire, thin is fine, from the case of the volume control or the ground side of the jack to the tailpiece. My 1100 has no hum at all, unless I put it very close to the amp, within a few inches, where every guitar I have is noisy.

[Elkus]

You need to make sure the strings are grounded through the tailpiece. You need a wire, thin is fine, from the case of the volume control or the ground side of the jack to the tailpiece. My 1100 has no hum at all, unless I put it very close to the amp, within a few inches, where every guitar I have is noisy.

I installed a endpin jack, which I thought would ground my tailpiece. I used push clothe wire.

[richpiv]

I have one. I use an EH Hum Debugger, works well and just very slight change in tone, not really noticeable IMHO.

[Elkus]

I have one. I use an EH Hum Debugger, works well and just very slight change in tone, not really noticeable IMHO.

Gotcha, looked into one of those. I don't mind the hum much, especially for gigging purpose. If I were to record I would probably want the hum debugger.

[sgosnell]

The endpin jack might or might not ground the strings. It depends on the pin you used for the ground wire, and whether the jack is in solid contact with the tailpiece. On some endpin jacks, one of the pins connects to the sleeve of the instrument cable plug, but not to the case of the jack. Your symptoms are the classic ones for ungrounded strings.

[rpjazzguitar]

You can check it by taking any piece of wire and putting one end on the ground (outer parts of the jack, for example, or cases of volume pots) and the other end on the tailpiece. Basically, it mimics the string ground wire, for diagnosis.

[sgosnell]

Yes, but the outer part of the jack may or may not be connected to ground. It depends on how the jack is wired. You can check continuity between the pickup cover and the jack exterior, or to check if the strings are grounded, from the pickup cover to the strings. There should be continuity between the pickup exterior and the strings. If there isn't, make it so.

[KirkP]

Your symptoms are the classic ones for ungrounded strings.

I don’t think that’s correct. If touching the strings eliminates the buzz, that means the strings are grounded. If touching the strings has no effect on hum or makes it worse, then the strings need to be grounded. I confirmed this claim on my own guitar by disconnecting the wire between my strings and the outside of the endpin jack.

[KirkP]

If I touch the tailpiece, end pin or strings the hum is gone.

That’s as it should be. I have a reissue 1100 that’s properly grounded including to the strings, and that’s how it responds.

I’ve played single coil pickups most of my life and learned workarounds to deal with buzz (it’s usually not a 60 Hz hum). First thing after plugging in I’ll do a buzz check. If there’s too much I’ll try to look for the source, which might be a dimmer, TV, or other gadget and either turn it off, move away from it, or change the angle I’m facing to put the source a the null of the pickup coil (which is acting as a directional receiving antenna). Sometimes I’ve ended up facing in an odd direction relative to the audience or bandmates, but it’s worth it to reduce the buzz.

The buzz probably can’t be completely eliminated without touching the strings or another metal part on the guitar, so I try to always touch some metal unless I’ve cut the volume knob to zero. When I’m playing, if my fretting fingers aren’t clamped on the strings and I hear a little hum, I’ll unconsciously rest the heal or side of my right hand on the strings or bridge to tame it. Between tunes, the volume knob always goes to zero.

I’ve been pleased with how buzz resistant the 1100 seems to be for a single coil pickup—much more so than my Tele or Strat.

[wintermoon]

That’s as it should be. I have a reissue 1100 that’s properly grounded including to the strings, and that’s how it responds.

I’ve played single coil pickups most of my life and learned workarounds to deal with buzz (it’s usually not a 60 Hz hum). First thing after plugging in I’ll do a buzz check. If there’s too much I’ll try to look for the source, which might be a dimmer, TV, or other gadget and either turn it off, move away from it, or change the angle I’m facing to put the source a the null of the pickup coil (which is acting as a directional receiving antenna). Sometimes I’ve ended up facing in an odd direction relative to the audience or bandmates, but it’s worth it to reduce the buzz.

The buzz probably can’t be completely eliminated without touching the strings or another metal part on the guitar, so I try to always touch some metal unless I’ve cut the volume knob to zero. When I’m playing, if my fretting fingers aren’t clamped on the strings and I hear a little hum, I’ll unconsciously rest the heal or side of my right hand on the strings or bridge to tame it. Between tunes, the volume knob always goes to zero.

I’ve been pleased with how buzz resistant the 1100 seems to be for a single coil pickup—much more so than my Tele or Strat.

Good post, it can be a battle w old single coils. But I had a terrible problem w my old humbucker L5 at a club not long before the lockdown.
Culprit was a big neon on the wall behind the stage of course, but it was the club's name so it wasn't getting turned off and I had to palm the strings the whole night, worst I've ever experienced,. I've dealt w hum on gigs a million times but this was ridiculous, can't imagine how much a single coil would've buzzed there.
But the soundman said it's par for the course, nothing he could do.

[sgosnell]

If the strings are grounded, touching them should make no difference. Grounding can be checked with an ohmmeter or continuity checker easily enough. There should be continuity between the exterior of the pickup and the strings. You provide that connection through your body if it isn't present, when you touch the strings or tailpiece or the cable plug if it's metal.

[KirkP]

Unless you are standing barefooted on a wet concrete floor, your body is probably not grounded. In fact, it might act more like an antenna!

But you can ground your body by making good contact with a ground point on your guitar. Since your body has so much salt water, if it’s grounded it’s conductive enough to act as a shield, reducing the noise that gets into your pickup coil. That’s why making good contact with grounded strings should reduce the noise. Lightly touching the strings usually isn’t enough. The harder you push or the more surface area the better your body is grounded. But if the stings aren’t grounded, touching them probably won’t reduce the noise at all. I’ve confirmed this claim with my own experiment.

[Cunamara]

You need to make sure the strings are grounded through the tailpiece. You need a wire, thin is fine, from the case of the volume control or the ground side of the jack to the tailpiece. My 1100 has no hum at all, unless I put it very close to the amp, within a few inches, where every guitar I have is noisy.

He said that if he touches the strings, the hum is gone. Therefore the strings are grounded.

[pingu]

If the strings are grounded, touching them should make no difference.

nope that’s wrong ....

[aquin43]

The amplifier is grounded but both the guitar body and the player pick up hum, the player picking up most. The player transfers hum to the guitar so grounding the strings shorts the player's hum voltage to ground. String grounding doesn't address the basic problem which is that unshielded parts of the circuit will pick up hum from the guitar body which is quite conductive, given the minuscule electric currents involved. If the unshielded parts of the pickup circuit, such as the output jack, the pots and the tone capacitor are kept away from the wood of the guitar by sticking grounded pieces of copper foil between them and the guitar body or scratch plate the hum problem disappears.

The impedance of the pickup is quite low at low frequencies but the impedance of the circuit seen from the jack rises as the volume is turned down, peaking at 6dB attenuation. That is why you might notice that the hum can be greater with the volume turned down a bit unless the wiring is shielded at the jack or grounded copper foil is placed on the guitar wood in the region of the jack.

[sgosnell]

I have a mandolin that I built, which uses a wooden tailpiece. I'm absolutely certain the strings are not grounded. It has a humbucker installed. It has a loud hum much of the time unless I touch the strings. When I'm playing and touching the strings, it's quiet, no noise, but as soon as I remove my hands, it's noisy. Temporarily grounding the strings removes the noise. The strings on my guitar with the 1100 are grounded, and there is little noise. Yes, any single-coil pickup can be noisy under some conditions, there is no doubt about that. But it shouldn't be noisy all the time.

Terminology may be an issue. Grounding is really not the proper term. Electrical continuity is more precise. The guitar is not necessarily grounded to earth even if there is continuity between the strings and the pickup case. But that continuity has an effect on the noise the pickup receives.

[aquin43]

The hum that the OP is suffering from has absolutely nothing to do with the number of coils in the pickup - that affects only interference from magnetic fields. This hum is from the large electric fields produced by mains wiring and picked up capacitively by the guitar or by the player and then transferred capacitively to the guitar.

With the guitar being grounded at one point via the amp there is a voltage across the guitar body that produces an electric field within and surrounding the guitar because it is an imperfect conductor of electricity. Any exposed part of the live side of the pickup circuit will be in this electric field and will capacitively pick up hum while the grounded side will be at ground potential. There will, therefore, be a net voltage difference across the pickup circuit. Since any part of the guitar body can be carrying a hum voltage, rigorously separating or shielding the exposed live side of the wiring from the wood can solve the problem. Alternatively the potential of the guitar wood adjacent to any exposed live side of the circuit can be forced to zero by attaching adhesive copper foil connected to the ground side of the circuit.

If the interference is very great then the interference current that runs down the guitar lead to the amp ground can couple a voltage into the live inner of the cable. This is less common, but explains why some sources of hum seem to get through whatever precautions are taken.

Interestingly, with an instrument that hums because of poor shielding, replacing the guitar lead by a wireless link with a battery powered transmitter can sometimes solve the problem. The whole guitar, including the transmitter then floats at the hum voltage but there is no hum voltage difference between the live and nominal 'ground' side of the circuit and so no hum.

[Spook410]

I have a guitar with an Armstrong 12 pole that hums unless I touch the strings. Quite noticeably and enough to annoy someone listening.

I have another guitar with an Armstrong 12 pole that does not hum at all. Played in exactly the same space.

Both guitars have the strings grounded per a proper ohm meter.

Both guitars have the same wiring.

One has Schatten controls the other CTS pots.

So much for generalizations.

[aquin43]

I have a guitar with an Armstrong 12 pole that hums unless I touch the strings. Quite noticeably and enough to annoy someone listening.

I have another guitar with an Armstrong 12 pole that does not hum at all. Played in exactly the same space.

Both guitars have the strings grounded per a proper ohm meter.

Both guitars have the same wiring.

One has Schatten controls the other CTS pots.

So much for generalizations.

If you read carefully what I wrote above, you should have enough information to debug the faulty layout in the guitar that hums.

[KirkP]

The impedance of the pickup is quite low at low frequencies but the impedance of the circuit seen from the jack rises as the volume is turned down, peaking at 6dB attenuation. That is why you might notice that the hum can be greater with the volume turned down a bit unless the wiring is shielded at the jack or grounded copper foil is placed on the guitar wood in the region of the jack.

I’ve always wondered why hum can increase as the volume control is turned down. Thanks for that!

[Spook410]

If you read carefully what I wrote above, you should have enough information to debug the faulty layout in the guitar that hums.

If you read carefully what I wrote above, (why do some phrases sound so condescending?) both guitars are humbuckers (Armstrong 12 pole) and both are being played in the same space (same magnetic fields). Both have the same shielding and pickup wire (I installed the pickups). And both have a tail pin jack installed on a metal tailpiece. And using a battery powered amp doesn't change things. Neither has a faulty layout. It's probably a component issue that I'll get around to resolving when it bugs me enough.

There is no one source or solution for hum. Human as antenna is certainly a major cause. So are single coils picking up fields on their own. And then you have to consider a bad wire, cable, amp, overall grounding, et al.

[Cunamara]

I have a guitar with an Armstrong 12 pole that hums unless I touch the strings. Quite noticeably and enough to annoy someone listening.

I have another guitar with an Armstrong 12 pole that does not hum at all. Played in exactly the same space.

Both guitars have the strings grounded per a proper ohm meter.

Both guitars have the same wiring.

One has Schatten controls the other CTS pots.

So much for generalizations.

So the difference appears to be the pots from what you are describing.

[aquin43]

If you read carefully what I wrote above, (why do some phrases sound so condescending?) both guitars are hum buckers (Armstrong 12 pole) and both are being played in the same space (same magnetic fields). Both have the same shielding and pickup wire (I installed the pickups). And both have a tail pin jack installed on a metal tailpiece. And using a battery powered amp doesn't change things. Neither has a faulty layout. It's probably a component issue that I'll get around to resolving when it bugs me enough.

There is no one source or solution for hum. Human as antenna is certainly a major cause. So are single coils picking up fields on their own. And then you have to consider a bad wire, cable, amp, overall grounding, et al.

Are you implying that this vast difference in behaviour of the two systems has no ascribable physical cause? Why is it not a faulty layout? What component can lead to this difference while leaving the circuit otherwise functional? What is the relevance of magnetic fields to an electrostatic problem? Why mention single coils when it is well known that the pickup coil structure is irrelevant to the susceptibility to electrostatic interference? What is a "bad wire"?

I had no intention of being "condescending" but merely pointed out the contents of my post that related the electric field around the wood of the guitar and its relationship to the unshielded parts of the pickup wiring, of which there are usually many, to the level of induced hum.

Beyond that, it is all magic.

[Spook410]

Are you implying xxx.... snip.t..

Of course there is a physical cause. That physical cause could be inside the pickup. Part of the Schatten assembly. Some piece of wire the perfect length (can't find my Smith chart right now..). None of which is a faulty layout though a faulty cold solder joint is still possible. It's just a list of possibilities some of which are more or less likely once environment and a solid ground has been isolated out. And I'm not sure why you keep insisting single pickups aren't noisier than humbuckers. Maybe you're using 'hum' very specifically whereas many use it more generally.

I have spent some time behind a scope. Two things:

1. It can always be the cable

2. If you let the magic smoke out, it doesn't work anymore