Hum cancelling question

[JazzNote]

I just noticed, when sitting before the amp with one of my floater equipped archtops, i can get totally rid of all hum when i turn the guitar into a horizontal position. Now i wonder about the reason for this to happen. Is it because magnetic fields are cancelled as a cause of this alignement? Could i put this discovery to use in terms of hum cancelling for this particular guitar/pickup combination in general?

TIA

[Cunamara]

Try keeping the guitar in the normal playing position and rotating your body so the neck is pointing towards the amp. IME hum is maximized when the face of the pickup is pointing to the source of EM interference.

[sgosnell]

The interference doesn't always come from the amp. It can come from routers, computers, lights, and all sorts of things.

[Cunamara]

Yup, so you might have to experiment with rotating around to see where the hum is minimized. If you can figure out where the interference is coming from that way, you might be able to stop it at its source. I have found compact fluorescent and LED bulbs in lamps to be culprits, wall dimmer switches, computers, my iPad and iPhone, etc., all as sources of hum.

Also, checking to see that the amp is properly grounded, that the guitar ground is working correctly can be helpful.

[John A.]

I just noticed, when sitting before the amp with one of my floater equipped archtops, i can get totally rid of all hum when i turn the guitar into a horizontal position. Now i wonder about the reason for this to happen. Is it because magnetic fields are cancelled as a cause of this alignement?

The fields themselves aren't canceled. The coil in the guitar pickup acts as an antenna for electromagnetic radiation produced by nearby devices (light dimmers, computer monitors, transformers, etc.). Exactly how much signal it picks up is affected by its distance from and orientation with respect to the source.

Could i put this discovery to use in terms of hum cancelling for this particular guitar/pickup combination in general?

You can try, but in environments with multiple sources of noise coming from multiple directions, moving around usually doesn't work very well. Humbucking pickups and properly shielded wiring in the guitar are the best line of defense against this kind of noise. With single coils, it's a lot more challenging. Pretty much the only thing that really works in bad environments is the Electro-Harmonix Hum Debugger pedal.

[sgosnell]

In the room where I practice, there are two computers with about 6 external drives but only one monitor, a router, two printers, an amplifier with wifi, LED lights, and probably more. It's a very noisy environment, and even humbuckers hum. I can usually find a quiet position, but sometimes it's difficult. I live with it because there is no location that is better overall, and I don't want to turn anything off.

[pauln]

Many sources of electrical noise have been mentioned.

LED lights are one of the worst because of distance - one LED in the house may be heard no matter where you play the guitar.

The worst of all is definitely unterminated coax branches of your internet provider. These are silent until you get within about 8 feet, and then they provoke a very loud roaring sound. Unterminated means a live signal coax connector that is not in use (not connected to anything), so they are those unused cable connections around the place. They may be silenced by connecting them to something (doesn't matter if the thing is turned on or not), or you may locate the splitter to which the branches are connected and disconnect at the splitter the ones not in use ... usually found in the attic, will look something like this; one input from the provider, multiple outputs (branches) to wall connections:


Both LED and unterminated coax are bad enough that in an apartment you may need cooperation from your neighbors.

[JazzNote]

Thanks to all of you for giving me valuable insight!

[Gitfiddler]

I keep one of these on my pedal board. It is only 'on' when needed, but is very transparent and effective for hum issues.

[Cunamara]

I have one of those and I completely forgot about it. It does do a decent job. Pat Metheny used one.

[Doctor Jeff]

For me and my (former) Godin Kingpin, old tube and post wiring in my prior house was the devil.

While adjusting guitar orientation might help to some extent, it’s not a convenient or reliable cure. My first Kingpin was pretty much unplayable until I got the Hum Debugger. Then it was fine. No major effect on tone IMO.

The Godin was the worst; other single-coil pickup guitars weren’t nearly so bad.

Although I have some T&P wiring in my current 100-year-old house, there aren’t too many hum problems, except with a certain SS amp I no longer have and with certain pedals. I have a couple of single-coil guitars and don’t notice any hum with them.

[John A.]

For me and my (former) Godin Kingpin, old tube and post wiring in my prior house was the devil.

While adjusting guitar orientation might help to some extent, it’s not a convenient or reliable cure. My first Kingpin was pretty much unplayable until I got the Hum Debugger. Then it was fine. No major effect on tone IMO.

The Godin was the worst; other single-coil pickup guitars weren’t nearly so bad.

Although I have some T&P wiring in my current 100-year-old house, there aren’t too many hum problems, except with a certain SS amp I no longer have and with certain pedals. I have a couple of single-coil guitars and don’t notice any hum with them.

Yup. My experience is that P90s are a lot more hum prone than Fender-style single coils. Makes sense, since they have a lot more wire and stronger magnets. I bought a Hum Debugger to use with the Kinpin I had. I did a couple of gigs with the P90 Les Paul I got recently without using it, but next time I most likely will.