High Gain Noise

[Steve Conner]

My guess is that other countries have regulations in place as well.

Yes, in the UK we have to conform to the European standards.

At work, I have to design for EMC and our products have to get tested, which is yet another headache. The EMC test house uses a mish-mash of the various different standards to make sure our gear will pass them all and be legal for sale worldwide. And they charge thousands of dollars for doing it. Technically all of you boutique amp builders should be EMC testing too, but that's a hot potato issue I should stay away from.

Those triac things suck, my Strat can hear the one in my washing machine from two rooms away.

Again, guitar pickups are very sensitive to low-frequency magnetic fields, and the statutory limits for these are quite relaxed, probably because CRT TV manufacturers lobbied for it. So products that pass EMC (like my washing machine or any lamp dimmer that's legal for sale) can still mess up your guitar.

[Mike Sulzer]

Again, guitar pickups are very sensitive to low-frequency magnetic fields, and the statutory limits for these are quite relaxed, probably because CRT TV manufacturers lobbied for it. So products that pass EMC (like my washing machine or any lamp dimmer that's legal for sale) can still mess up your guitar.

Yes, and so imagine my surprise when I read on the pickup forum here that matching the sensitivity of the two coils in a humbucker is not very important. 10% tolerance of # of turns is supposedly more than good enough, and even worse is quite acceptable for the goal of achieving a unique sound. And there seems to be no effort to make sure that slugs and screws match in sensitivity.

I find that getting it to a few percent is worthwhile. The environment is quite a bit worse than when the humbucker was invented in the late fifties. Switching devices produce high harmonics in the magnetic field (buzzing). Before the widespread use of switching devices, a buzz meant interferene from an electric field. Now it can be either. Magnetic field interference used to mean low harmonics and fundamental from a transformer.

[Steve Conner]

Mike, yes, this is an interesting point.

I recently replaced the humbuckers in my PRS with Duncan Alnico 2 Pros, on Dave's recommendation.

Now the new pickups sound great, but they're not particularly good at bucking hum! The old PRS ones cancelled hum more or less completely, but the Duncans still let a little through. Yes, I wired them up correctly!

I'm sure Seymour knows what he's doing though: if he has to mismatch the coils to make them sound as good as they do, then that's fine.

[jrfrond]

I too have noticed in the last several years that side-by-side humbuckers don't seem as effective as they used to be, across the board from many brands. Stacked designs seem to be dead quiet. My guess is because stacked designs possess a design anomaly of better LOW-frequency cancellation, as opposed to the reverse with side-by-side humbuckers, and most of the offending noise is relatively low in frequency.

Another thing you can do is to avoid high-output pickups. Higher output = higher-Z = more wire turns = more noise. Yeah, there are some purists who want to hit the front-end of an amp hard without any distortion boxes, but high-output pickups just make better antennae.

In the last several years, I have personally been favoring lower-Z, slightly underwound pickups anyway. Not only are they less noisy, but they sound better to my ears, and when you DO kick in that distortion, they remain articulate. My current favorite humbucker is TV Jones for that reason. The FilterTron design is just right.

[Mike Sulzer]

I think it would be better to construct humbuckers for the best cancellation and find some other way to alter the sound.

What does this do, anyway? (different number of turns) The self-resonances of the two coils are much higher infrequency than the resonance formed by the two coils in series and the cable capacitance. (That is, the capacitance of a pickup coil is a lot less than that of the cable.) So it should not matter much that the two coils have different inductances; it should be the sum that counts.

Maybe it has something to do with coupling between the two coils, but I do not see what.

[defaced]

Oh, another source of noise I failed to mention: triac-controlled light dimmers and speed controls.

I've removed every light dimmer in my house because of this. They were impossible unless turned off, and it's no fun to play in the dark.

[niqstu]

Resolved!!!

... it was the neighbors in-ground fence for their dog. Ugh, how could I have overlooked that. It went off the other day and it was great, just great. I can play without the gate, not with the tv on though, and I didn't feel tense from trying to stay in a fixed position. Neighbor said I could rewire his fence for him, away from my front room. sorry, on the verge of jrunk post here, so I think i'll go and play.

[David Schwab]

I too have noticed in the last several years that side-by-side humbuckers don't seem as effective as they used to be, across the board from many brands. Stacked designs seem to be dead quiet. My guess is because stacked designs possess a design anomaly of better LOW-frequency cancellation, as opposed to the reverse with side-by-side humbuckers, and most of the offending noise is relatively low in frequency

I've experimented with stacks, and they do indeed cancel out a lot of low frequencies.

But it seems it's popular to mismatch the two coils on side-by-side humbuckers lately.

So it should not matter much that the two coils have different inductances; it should be the sum that counts.

I make pickups that use different wire gauges on each coil, but the same number of turns, and they are nice and quiet.

Oddly enough I'm finding that sidewinders tend to pick up more electrical field noise, but I don't know why.

[jrfrond]

Oddly enough I'm finding that sidewinders tend to pick up more electrical field noise, but I don't know why.

In my head, it is because of the wider magnetic window, but I don't know for sure.

[Dave Kerr]

... it was the neighbors in-ground fence for their dog. Ugh, how could I have overlooked that. It went off the other day and it was great, just great. I can play without the gate, not with the tv on though, and I didn't feel tense from trying to stay in a fixed position. Neighbor said I could rewire his fence for him, away from my front room. sorry, on the verge of jrunk post here, so I think i'll go and play.

The dog's probably trained by now to stay away from the boundary, he probably doesn't even need the fence anymore.

[12Bass]

... Oddly enough I'm finding that sidewinders tend to pick up more electrical field noise, but I don't know why.

A couple more data points: My Lane Poor M3.5Ws are definitely more sensitive to EMI than other pickups. However, the Q-tuner BL-5 in my Pedulla seems relatively impervious. Both are sidewinders, IIRC....

[David Schwab]

A couple more data points: My Lane Poor M3.5Ws are definitely more sensitive to EMI than other pickups. However, the Q-tuner BL-5 in my Pedulla seems relatively impervious. Both are sidewinders, IIRC....

Yeah, the Q-Tuners are very quiet, and they have no shielding, and the metal poles are not grounded either.

I can't explain why I'm getting more EMI interference with the sidewinders than my side-by-side humbuckers. I've changed my shielding method which helped a lot.

[Steve A.]

... it was the neighbors in-ground fence for their dog. Ugh, how could I have overlooked that. It went off the other day and it was great, just great. I can play without the gate, not with the tv on though, and I didn't feel tense from trying to stay in a fixed position. Neighbor said I could rewire his fence for him, away from my front room. sorry, on the verge of jrunk post here, so I think i'll go and play.

Glad to hear that you tracked it down! I'm dealing with a similar issue in the 4 plex I live at. When I turn my guitar amp up a little bit the "kitty corner" neighbors turn something on that generates a lot of EMI/RFI crap. With a single coil guitar rotating around can usually find the spot that is most quiet, but with a lap steel there is nowhere to run... Is it the top of the coil that picks up the crap or the side of the coil? I ask because there are no wires over me in my attic or in the slab.

Does a plasma TV emit the same crap as a CRT?

I had neighbors directly next to my music room. As long as their cable hookup was on the opposite side of the living room everything was fine, but they had it moved to the wall we have in common and I started picking up all sorts of crap. But that unit has been vacant for quite awhile.

With all of your experiments I guess it would do me no good to try shielding my wall or filtering my AC power... *sniff!*

Steve Ahola

P.S. Perhaps my neighbors are using cheap dimmers. Is there any way I can filter that crap out? I stopped using dimmers a long time ago because of the noise.

[J M Fahey]

As a general purpose simple solution, I suggest you use your guitar (or bass) itself as the noise detector, since it already does it so willingly.
Get a long cable and walk around, also rotating and taking note of maximum and minimum noise angles.
You'll soon be able to "map" it and soon get to the "so THIS *$%&"@#~ p.o.s. was the guilty one?" moment.
If noise is constant everywhere and does not change with orientation, consider moving.
I already mentioned here that "tick tick tick zzzZZZTTTZZZzzz tick tick tick" noise I had once, 5 seconds on, 20 off, repeating for a couple minutes and dissapearing for up to 1 hour.
It was the Radar from a Spanish fishing ship, anchored 1 block from my house.
(Yes, I live in the ancient Port of La Boca in Buenos Aires)
As another unusual example, a friend had incredible hum in his house; it made playing impossible , but only from , say, 6 AM to 4 PM, on weekdays.
Once they had to repair this HUGE subterranean power line, feeding a big metallurgical factory close by and he found out.
Part of it went almost under his house.
Yea, I know, 3 phase power *should* cancel itself out, but it did not in that case.