How to Power Guitar Pedals 101 (the basics)

Back in the day, I was a little surprised to find out that guitar pedals didn't just work on their own. They each need a power source, and for those that might be newer to the world of guitar pedals (like I was) it's not immediately clear as to how that happens or what can serve up that power. However, the answer is fairly straightforward. To power guitar pedals you have essentially four options:

• 9V battery (one for each pedal)
• Single adapter wall plugs
• Daisy chain wall plug (plugs into multiple pedals)
• Isolated power box with an electrical cord to each pedal

All of these are valid methods of powering your guitar pedals, though they all have their pros and cons. How you're approaching your guitar pedal collection will determine which one is best-suited for you.

I'll talk a little bit about each method covering the pros and cons.

9V Batteries

One of the most common methods of powering guitar pedals is a single 9V battery, since most pedals need 9V to operate. This can get trickier with 12V and 18V pedals, though those are far less common. For example, all the small Boss pedals can be powered by a 9V battery connection. Depending on the pedal, you'll have a compartment that can be opened where the battery can be easily attached.

The problem is that guitar pedals are notoriously power-hungry and will drain 9V batteries rather quickly. Even when you have a pedal turned off, with the instrument cables plugged in, it'll still pull power. After going through enough 9V batteries, this gets pretty expensive.

Battery Pros

• Cheap (at first)
• Easy to obtain
• Easy to install
• Isolated (less noisy) source of power

Battery Cons

• Gets expensive after awhile
• Needs to be regularly replaced
• Not reliable for live shows (risk of power running down)
• Not all pedals run of 9V (some 12V or 18V)

Single Adapters

The next step up from a 9V battery would be a single 9V power adapter that plugs into a wall, like this 9V AC-DC power supply:

These adapters are an improvement over a battery in regards to the battery running out. With a permanent adapter, it can always provide power without having to be replaced. The problem with it is that it only provides one source of power, meaning additional pedals will require additional power sources, and an outlet for every single pedal you want to add, assuming they're all powered with a 9V power supply that plugs into the wall.

Thus, we've solved one problem and replaced it with another. We no longer have to worry about batteries running out of power, but each power source we have is only good for one stompbox.

This can work for smaller pedalboards, but will quickly require a more robust solution that hogs up less outlets.

9V Single Supply Pros

• Affordable and permanent
• Isolated form of power (single supply for each pedal)

9V Single Supply Cons

• Each supply requires its own outlet
• Multiple power supplies can get really messy
• Not ideal for more than one or two pedals

Daisy Chain Adapters

You might have heard the term "daisy chain" in reference to guitar pedal power, but weren't exactly sure what it meant. In basic terms, it's a power supply that extends power through a chained connection that all stems from one outlet. Here's how it looks in a Donner daisy chain power supply:

While this solves the problem of needing multiple outlets, it does pose a major technical issue that isn't immediately apparent. All of those chained power source are "un-isolated."

What is isolated power and why does it matter?

A power supply is isolated when it's sheltered from all other power circuits, existing in a one-to-one relationship with the device its powering. In other words, each pedal has its own source of power where that power source doesn't cross paths with any other power sources.

In a daisy chain, this is not the case as all sources of power are shared.

What's wrong with that, you ask?

It can be really noisy.

Daisy chains and unisolated power boxes are notorious for creating electrical crossover and noise problems. As you increase the number of pedals that are chained together with non-isolated power, your odds of having noise problems goes up dramatically. Like I said about the individual power supplies, daisy chains are a decent fix for maybe three pedals at most. Any more than that, and I'd advise moving on the our fourth and final option.

Daisy Chain Pros

• Extremely cheap
• Easy to setup
• Eliminates the need for multiple outlets

Daisy Chain Cons

• Power sources are not isolated
• Notorious for causing noise issues
• Can still have trouble handling different voltages

Isolated Multi-Source Power Supplies

The only pedal power option that solves all these problems is an isolated power supply box, like this one from Voodoo lab: 

These power supplies only require one wall outlet, but then isolate power to each individual power output on the box, which you can see in the above picture. This eliminates all the problems we've had with the previous three solutions. It requires no batteries, only one wall outlets, and solves the noise issues by isolating each individual power source.

For all pedal and effects setups, we recommend this type of power, despite the fact that isolated power supplies are fairly expensive. It's not uncommon to spend $150 - $200 on one of these boxes, which is certainly a downside to consider.

However, if you run even four or five guitar pedals, we'd recommend investing in an isolated power supply.

Isolated Power Supply Pros

• No batteries required
• Needs only one outlet
• Often provides multiple voltages within a single box
• Provides isolated power through each power output
• Easily powers multiple pedals at once

Isolated Power Supply Cons

• Significantly more expensive than the previous options

Pedal Power Summary

It's hard to want to throw $200 at an electrical/utility device for your pedalboard. However, it's necessary if you want to even consider expanding your pedalboard past just a few stompboxes. For me, even trying to use more than two pedals at once almost requires that a professional-level isolated power source be used.

However, it's also important just to know the other options available to you so you can make an informed choice about how to power your effects.

We'd advise making it a priority before you start to add a lot of pedals to your rig.

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