One of the most popular questions students tend to ask about their electric guitars is why their pickups hum and buzz through the amp...
There are generally two sides to this question. One side is how come their pickups will buzz, but then go quiet when they turn to a certain angle. Another side to this question is how come their amp will be quiet at one moment, yet at another moment the amp will begin to hum and generate buzz seemingly out of nowhere.
There are several possible answers and sides to both of these questions. But, the overall reason for why we get hum and buzz through our amps has to do with, "electromagnetic fields."
Guitar Pickups, (and other devices, such as, fan motors), will amplify electromagnetic fields coming from other appliances along the electrical line that your amp is plugged into. They also amplify any power fluctuations from your electric companies distribution transformer, (the unit somewhere near to your home that steps down the power from your neighborhood power sub-station).
The important thing to grasp is that the electrical power coming from the plugs located in your house is not perfect, nor is it generally very clean. That is why companies like Furman make power conditioners like the, "Furman PL PLUS C," for recording studios and for live venues.
The power found in a typical house plug can be affected in many different ways. Even something seemingly harmless, like running a vacuum in another room of the house, can create an annoying hiss or buzzing sound from your amp. And so, power conditioners can make a big difference in eliminating pops and clicks from; heat pumps, refrigerators and fan motors.
These power issues can be a big problem depending upon where you live and how clean the power in your neighborhood is. For example, if you play out a lot, you'll notice that some venues will cause your amp to start to hum when turned up loud, but in other places this won't happen.
Years ago, I thought all of this was just something that speakers and amps did. However, after buying a power conditioner I found the noise greatly diminish in many venues.
In clubs, halls or jam spaces the cleanliness of the power will be different. Sometimes power conditioners will do something, and other times they won't. This is because of the very nature of the lines of force in a magnetic field.
LINES OF FORCE:
Think of it like this. The pickups in a guitar are the most quiet when they are "in line" with the external magnetic field. However, when they become 'out of line' they will start to hum. The result is manipulated like this; if you face one way, your guitar will be quiet. But, as you start to turn another way, the hum will start to amplify.
Unshielded single coil pickups are by far the worst for this issue. And, the problem concerning these external magnetic fields only compounds if you switch your amp into the over-drive channel. Shielding can help protect your electronics in some circumstances. But, the best solution for the most quiet sounding guitar is to use hum-bucking, (double-coil), pickups.
DEALING WITH DIRTY POWER:
Now, that said about the guitar and it's pickups, we still haven't fully addressed the issue of dirty power. We can have a guitar that is well shielded running hum-bucking pickups, but what about that vacuum across the hallway, or that neighbor who's building a new garage and is using a high-power skill saw? We'll still have an issue with powerful electromagnetic fields generated along our electrical path. They are out of our control and they will make it to our amps and to our guitars.
There are different directions we can take that can sometimes help us with this "Dirty Power" issue. Unfortunately, the simple truth is that getting 100% clean power to an amp, (and through to your guitar), can be incredibly difficult. And, the problem is only made more complicated - and outside of your control - when you're out on a gig.
The bottom line is that the most control that you'll have over your power will always be within your home studio setting. Through the use of; Isolated Power Systems, Isolated Grounds, Voltage Regulators, Battery Back-ups, and Power Conditioners you should be able to maintain a fairly clean power source when you need it most, (when making your home recordings).
A few important points to always consider about your power set-up are:
- An automatic step up system for low voltage and step down high voltage. This will always maintain levels that are safe for your music equipment.
- A device to shield your hardware from damage by providing both Lightning and Surge Protection.
- EMI/RFI filters to prevent line noise from corrupting your system.
- A device to monitor and balance input voltages. This will protect your system from anything that might cause the output voltage to fall outside of the normal correction band.
- A multi-stage device that incorporates three stages of conditioning using the following components.
1. Low impedance isolation transformer (toroid).
2. High quality AC noise filters
3. Surge diverter - diverts all noise to ground.
While it may not be possible to maintain absolutely perfect /clean power 24 hrs. a day, at your home studio or out in the club scene, we can work toward laying the best possible foundation for a power environment that should allow us to perform and record without a lot of unwanted, "buzz /hum /pops or hiss."
Unfortunately, it is important to keep in mind that the chances of completely removing all of the line hum and buzz will be next to impossible. Things like isolating sound boards from amplifiers and using power conditioners will never be sufficient to eliminate all of the ground loop hum in the system.
Electromagnetic hum is a larger problem that requires tracking down where everything in the system is plugged in, (if live, that means the stuff on the stage that is far away from the sound room). This also includes even far flung sources of interference such as; cable tv, phone lines, motors, computers, projectors, etc.
It sure would be super nice if some company in the electronics world could build a reasonably priced unit that could at least detect if not entirely eliminate 60 Hz hum, rather than pass it straight through. Oh well, maybe one day!
I hope you will be able to use some of this information in this post to make an informed decision for cleaner /better power in your guitar study and work environments.
Thank you for reading this week's Blogger article.
All the best - Andrew Wasson