Noise is a demon that plagues all high gain distortion pedals. It's a fact of life that there's just no escape from … or is there?
Before we begin lets take a moment to define the word 'noise' as we use it in this article. When we use the word noise we're referring to the hum & hiss you hear when you are not playing. The moment you strike a note, the noise is 'gone', but in reality it is simply overcome by the note having been played. The note is passing trough the distortion circuit and being amplified in the same way the noise is, but being that the note is intentional and, as such, a much louder source than whatever is causing the noise in the first place. As the struck note decays the noise slowly becomes more apparent until it overcomes the decaying note, as the noise never left, it was simply overpowered by the note.
Why are distortion pedals noisy?
Many distortions use cascading gain stages to create their sound. While this creates some great distorted tones, each gain stage also amplifies all background noise.
Not all distortion pedals use this design, but the long and short of it is that a distortion pedal will amplify and distort any signal it is fed; even if you can not hear the noise causing signal source before activating the pedal.
What could be causing the noise?
Many times, the noise accentuated by distortion pedals can be tracked to environmental issues. This is why professional recording studios are so expensive to design and construct. Painstaking measures are taken to ensure that every power source is pristine, ever power line is shielded and kept far from physical audio paths, all of the walls are shielded against stray radio frequencies, and so on.
That being said; Let's take a quick look at what might be causing your noise and a few things you can do to clean up your signal.
The first thing to look at is how you're powering the unit. Batteries will deliver a quieter performance, as they are not subject to some of the issues that affect AC power, but they have a downside as well. Batteries will steal your tone as they die, at such a subtle rate, you might not notice until your tone is truly not the same anymore.
AC power eliminates the gradual tone theft caused by dying batteries but they open the door to other noise causing possibilities. AC power directly from the wall is wrought with noise. The power is not delivered in a conditioned or filtered manner which is perfectly acceptable for most worldly applications, but not in the audio realm. If you rely heavily on pedals of any kind to create your tone, we highly recommend investing in a good power supply for them. Here in our shop we use the PA9 power supply from Godlyke, but there are many others on the market.
Another power distribution possibility could be that you have too many pedals on your power supply's chain. Noise occurs when you overload your power supply's capacity. The rated output of your power supply might indicate it can handle 4 or 5 pedals (after doing the math of course), and in fact it can-it just can't handle it well. That output rate is there to tell you where the failure point would be, not where the optimum operating level is. To keep your pedal board sounding clean stay well under your power supply's rated output. Some pros suggest you cut the rated output in halve and use that as your load guide. I say use your ears. If you hear degradation, even while within the specs of your power supply, ease back on its load.
Why are you plugging your $ 1000 guitar into your $ 1500 amp with a $ 9 cable? And DO NOT get me started on those $ 3 patch cables you're using in between each pedal on your board. C'mon guys … your cables are essential to your tone, so skimp someplace else.
Our good friend Mark Stoddard over at Lava Cable chimes in with this angle:
" Noise or microphonics is caused by cable movement or contact as small voltages are generated from this that interrupt the signal path. If the cable does not have the correct amount or type shielding the noise will be greater. Also, the lower in capacitance a cable It is, the easier the noise will be heard as more signal is passed. Typically, with static cable such as pedal jumpers noise is not an issue as there's no movement. It's important for cable jumpers to be solidly built as a loose solder connection or loose solder-free connection can cause noise when the pedal or cable is moved. "
This is good info, lets expand on it a bit-pedal jumpers or patch cables actually take some serious abuse if you're a heavy footed pedal user. Every time you're stepping on the switch you're causing that whole unit it shift, unless your using mounting screws to keep your pedals on your board, and that slight shift with each stomp causes your patch cables to move and flex as well. So each time you engage your boost pedal for a solo, lets say once per song multiplied by 10 songs a set, thats 20 stomps … that can add up to some sizable movement over the course of the evening, not to mention the movement your cable plugging your ax into your pedal board is seeing. So you want to be sure that these are well constructed.
The other topic Mark touched on is capacitance. Over at Lava Cables web site they have a great write up on capacitance, and cables in general, I encourage you to check it out. But in a nut shell, capacitance sucks the high end out of your signal. The longer the cable the higher the capacitance, which is why 40 foot cables sound dark and muddy. So, stick to the correct cable length. If you're a bedroom rocker, a couple of 5-8 foot cables is probably all you need. If you're gigging try 12-15 footers, they'll probably do you well for most venues.
Do you have any quiet spots in the room you currently play in? Meaning- if you move around in the room do you have spots that are less noisy? If you do that tells us you've got something floating around in the air which might be quieted by shielding your guitars cavities.
Shielding the cavities of your guitar is not all that difficult, it can be time consuming, but not hard; However, the end results can be amazing. What shielding does is it prevents radio frequencies and other 'noise' from entering your pick ups. The shielding doesn't make the 'noise' signals bounce away, it actually absorbs the noise. The conductive material in the cavities attracts the signal and sends it to ground rather than letting it float around your pick ups. There are a lot of different methods to shield your guitar, so do your research. You can probably start and stop at GuitarNuts.com. GuitarNuts has been offering tips and guidance for shielding and pickup re-wiring for years, and they're a great resource. I've rewired more than my fair share of instruments using their diagrams, check them out!
Pedal board config
Heres a real example from a customer that had horrible noise issues with his Body Rot II. His pedal signal chain was a GE7 EQ to 'scoop' his tone, then running into the Body Rot II, then some reverb and delay. Here is exactly what I told him via Email:
One thing I would recommend right off the bat-put the GE7 at the end of your chain (before your delay or reverb) to sculpt your entire tone. If not at the end, certainly after the BRII. Essentially the BRII will take the boosted signals produced by the GE7 and distort it. Causing noise when there otherwise not be any.
With the tone 'scooped' by the EQ, the highs are boosted, then feeding those boosted highs into the BR2 to further boost and distort, caused hellacious noise. Simply moving the EQ cured his problems.
Another common noise causing problem the fact we use the volume knob on our distortion pedals as a master volume. Yes its handier to use the volume control on your pedal to turn your amp up and down, but its causing more noise than you need to hear. Let the amp do the heavy lifting. Set your pedals volume to the same level on or off (unity gain-ish) and use your amp to give you more volume when you need it, this will clean you up greatly.
Do you have any computer monitors in the room- the older big monitors, not a flat panel? If so, you're probably going to get noise.
Any fluorescent lighting in the room, either overhead or on a wall? If so, you're probably going to get noise. Even the new compact fluorescent bulbs that are going to be the only types of bulb we can buy in the near future are noisy. The best cure for both the old monitor noise and the fluorescent light noise is to shield your guitar, but even the best of shielding can't eliminate the noise those sources cause.
One last thought-noise gates are always useful in high gain situation. Sometimes there's just no way around them.