Pedal Power Supply Guide
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In this article, we're going to look at the best pedal power supplies. We'll also learn about the basics of pedal power: how it's measured, what causes noise and hum, what isolated mean, and more! We know that pedal power supplies aren't exactly the most exciting subject you'll come across in your guitar career. However, a good guitarist pays attention to every single part of their rig. Even if you have the best guitar, amp, and effects pedals, a bad power supply will muddy your tone and make you sound terrible!
Good power supplies can eliminate noise you might be experiencing from your pedal board. They'll help you get rid of those wasteful 9-volt batteries that you need to change every couple of weeks. Pedal power supplies will also make it easy to clean up and organize your pedalboard so you're not carrying around a rat's nest of wires to practice and gigs.
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If you're short on time, we've summarized our recommendations for the best effects pedal power supplies here. If you prefer to learn more about pedals, then keep reading! A more thorough analysis of these pedals is at the bottom of the article.
Let’s start with the obvious: effects pedals won’t operate without power. They contain complex electronics that need electricity to function. Pedals get the power they need from a battery, power supply, or directly from a wall outlet.
Pedal power requirements are measured in two ways: voltage (measured in volts, or V) and current (measured in milliamps, or mA). Think of voltage as ‘electrical pressure’ – like the water pressure of the pipes in your home. The higher the voltage, the higher the ‘pressure’, and the more readily electricity will flow. The rate at which electricity flows is called current. Current comes in two flavors: direct (DC) and alternating (AC).
Alternating current (AC) is what comes out of the outlets in your home. Effects pedals (and many home electronics) require DC power. Power supplies and AC adapters convert the AC from your outlets into pedal-friendly DC. A battery provides DC by its very nature, so it doesn’t need any conversion. Most pedals you’ll come across will need 9 volts of DC power, which is why a 9-volt battery is sufficient to power these pedals.
For a more concrete example, take a look at this TC Electronic Dark Matter pedal pictured above. It accepts 9 volts (9V) at 40 mA. This means that, in order for it to function correctly, the pedal must receive 40 mA of current at exactly 9 volts. Other pedals will have different voltage and current requirements, so be sure to read the label! If it's not on the pedal itself, then check the owner's manual. Providing a pedal with a higher voltage will cause damage! Current requirements are a bit more forgiving. As long as the power supply's current rating is equal to or greater than pedal's rating, you're good-to-go. The pedal will only pull the current it needs. The vast majority of pedals require 100 mA or less. However, there are exceptions. Strymon pedals are famous for their large power requirements - usually 250 mA or more!
The T-Rex Fuel Tank Jr power supply, for example, has five 9v outputs rated a 120mA each. Will it be enough to power the TC Electronic Dark Matter pedal we saw before? Let's check. The Dark Matter requires 9 volts. The Fuel Tank Jr.'s outputs are all rated for 9 volts. Good! What about the current requirements? The Dark Matter needs 40mA of current to operate. The Fuel Tank Jr. is rated for 120 mA of current for each output. That's perfect! The Dark Matter only needs 40mA, so it will only pull up to 40 mA of current from the Fuel Tank Jr. Everything checks out! Note that if we had a pedal that required 12V or one that needed 150mA of current, then we wouldn't be able to power it with the Fuel Tank Jr.
No matter how many pedals you have, a power supply can be an extremely useful addition to your pedalboard. Whether you're trying to minimize unwanted noise or you're sick of dealing with batteries, a power supply is your ticket to pedalboard nirvana. Let's take a look at a few of the major issues that you might be experiencing currently.
A battery is a very clean source of power that limits electrical noise. They're almost silent in their operation, which is great for musicians who want clean tone. However, in almost every other way, batteries suck. There's no way to tell how much life a battery has, so you won't know to replace them until it's too late. Even if your pedals are off, they're still draining their battery! To prevent this, you have to unplug the input from each pedal. That means you'll have to disassemble your pedalboard when you're done playing and put it back together again when you start playing. Even if you've accepted this drawback, you'll still need to keep replacing the batteries forever. You'll have to open up the pedal, replace the battery, reassemble it, and only then can you finally play some music. Doing this multiple times a month will quickly become exhausting.
Not all pedals have a battery-power option, so you're stuck using a power adapter. You might even choose to completely forgo batteries on all your pedals in favor of using power adapters. You did it! You're finally free of the evils of batteries! However, you'll quickly realize that this only works as long as you have enough outlets. You might think that buying a power strip will solve your problems. Though you will get more outlets, your pedalboard is now a wiring nightmare that's hard to organize and transport. You might also introduce hum, hiss, and noise into your signal chain this way because all the pedals are now in a ground loop. We'll talk more about ground loops next.
Using a power strip, daisy chain, or a cheap, unisolated power supply to power multiple pedals is almost guaranteed to cause some unwanted noise. When multiple electronic devices share the same ground connection, they're in a 'ground loop'. This makes them susceptible to interference and noise, which muddies up your tone and can be a source of great annoyance.
Remember that power supplies and wall-warts must convert the AC current from an outlet to a more usable DC current for your pedals. This process requires removing the 'ripple' from the AC current. A poor quality power source won't do a good job removing the ripple, which will make you susceptible to 60-cycle hum as well as other interference. That means even more unwanted noise! Even a noise gate pedal won't be enough to prevent this humming and interference.
Hopefully, it's obvious now why you need a good quality power supply. Dead batteries, messy pedalboards, and noisy interference aren't things any guitarist wants to deal with.
If you're looking to simply get rid of batteries and are ok with a little noise, then you might be happy with a daisy chain power supply like the TrueTone One Spot we'll talk about later. However, if you want the gold standard of power supplies, then you want an isolated power supply.
Completely eliminating unwanted noise should be our primary goal when it comes to choosing a power supply. However, this isn't always realistic to achieve - especially on a budget. If you've done everything to get rid of noise but still hear that dreaded hum, then you might need a power conditioner.
Let's take a look at daisy chains, isolated power supplies, and power conditioners in detail.
Daisy chain power supplies are an ok budget option. They're much more convenient than using a bunch of wall-warts to power your pedalboard. From just a single plug, you can power multiple pedals. Due to the design of the daisy chain, pedals are still in a ground loop. This means you're still susceptible to interference and noise. If you're a bedroom shredder who doesn't mind a little hum, then a daisy chain is the way to go. Headphone users, however, might find the hum is too much to tolerate. If you like to record, the noise floor of your recordings will be substantially higher. This will make for a less professional, noisy recording, so you might want to step up to an isolated power supply.
Isolated power supplies are today's go-to for powering your pedals. Rather than sharing a single power connection like a daisy chain, an isolated power supply fully isolates each connection. This means each pedal will have its own ground and power path, so it's not susceptible to ground loop noise. If you want the most silent way to power your pedals, an isolated power supply is the right choice.
Not all 'isolated' power supplies are truly isolated. A lot of the cheaper, Chinese-made power supplies like the Donner DP-1 are labeled as 'isolated', even though they're really not. Users on Reddit, YouTube, and other electronics/gear forums have come to the consensus that they are not isolated in the way we guitarists care about. Their 9v/12v/18v sections are electrically separate from each other, but that doesn't do much for silent operation. They're a step above daisy-chain supplies in terms of noise levels, but not by much.
Remember, the purpose of an isolated power supply is to prevent ground loops. The circuits of these cheap Chinese power supplies are not designed that way. If you want true, silent operation, then stick with our isolated power supply recommendations at the end of this article. A power supply isn't something you want to cheap out on, especially if you care about minimizing noise (which is one of the reasons why you're reading this)!
So you've bought an isolated pedal power supply and connected your pedals correctly. You've even stripped your rig down to the bare minimum, but for some reason, you're still getting noise. Even if you've done everything you can, you might still get some hum. In this case, you might need a power conditioner.
Not all power is created equally. Power can be 'high-quality' and 'low-quality', just like anything else in life. Remember, your house is wired for alternating current. Refrigerators, microwaves, washing machines, phones, and all the other appliances around your house cause interference in the wires. When power supplies convert AC to DC, they 'remove' the ripple of the AC current and also filter out this interference. Depending on how 'dirty' the power is in your house, the power supply alone may not be enough to clean up the power. In this case, a power conditioner can help.
A power conditioner plugs into your wall and 'processes' the power, removing interference, regulating any voltage spikes, and creating high-quality power that your equipment can happily use. After the conditioner does its job, there's no more noise or interference. It will also prolong the life of your gear and even protect your valuable equipment from surges!
Power conditioners are something of a last resort in your quest to quell noise. Don't buy one until you have an isolated power supply that you've tested out and are certain that dirty power is causing your noise issues. First, be sure that it's not your guitar or your cables that are causing the humming! If you turn the volume down on the guitar, but can still hear some buzzing, then check the cables. If the cables are fine, then the problem is likely your power.
Be careful when buying a power conditioner. Many of the cheaper options are just glorified surge protectors that do nothing to filter out interference. If you need a lot of outlets, then the Furman M-8X2 is a good choice. It's a rackmount unit, so it's pretty large. For a more compact solution, there's none better than the Furman AC-215A. It has two outlets: perfect for an amp and pedalboard.
The TrueTone One Spot is a decent budget option for the guitarist who wants to go battery-free. It's our only non-isolated power supply recommendation, so it will still be susceptible to 60-cycle hum and ground loop interference. If the power at your home, rehearsal space, or venue isn't good quality, then you're signing up for a lot of unwanted noise. If you're recording or you're sensitive to noise, then you'll want to upgrade to an isolated power supply. Daisy-chain power supplies like the One Spot are also notoriously sensitive when powering digital effects pedals. If you get noise with certain pedals and not others, you'll have to do some troubleshooting.
The One Spot can power up to 8 pedals with the supplied daisy-chain cable. Keep in mind that it can only power 9v pedals, so you'll have to leave your 12v or 18v pedals at home. It has a 1700mA total capacity that can handle all but the most power-hungry of pedals. To be sure it can manage your pedals, add up all the current requirements of your pedals (the mA ratings). If the total is less than 1700 mA, the One Spot will handle your pedalboard just fine. It comes with adapters to fit almost any pedal on the market. If you're on a tight budget, then the One Spot is a good stop gap until you can buy an isolated power supply.
The T-Rex Fuel Tank Jr. is one of the cheapest, fully-isolated power supplies on the market. It's compact and extremely lightweight at just over 18 ounces (~.5kg). Don't let that worry you though! It's made of metal and feels rock-solid. The T-Rex Junior has just 5 outputs, so those with larger pedal collections will need to upgrade to the T-Rex Chameleon or check out our other recommendations. Traveling musicians will love the built-in voltage selector feature that allows you to play in any country. Each output can support 120 mA of current, which is enough to power the majority of pedals on the market. If you have an Eventide or Strymon pedal, then you'll need something with more power, like the TrueTone 1 Spot CS7 below.
As-is, the T-Rex Fuel Tank Junior is only capable of supporting 9-volt pedals. If you have an 18-volt pedal you wish to use, you'll have to buy the voltage doubler cable separately. However, this will take up the space of two outputs, so you're left with just 3 other pedals you can connect. Instead of spending the $20 on the voltage doubler cable, consider upgrading to our next recommendation. However, if you like to keep your pedalboard as small as possible, you'll love the compactness and durability of the T-Rex Fuel Tank Jr.
The TrueTone 1 Spot CS7 is one of the best values in isolated pedal power supplies. While it's not as compact as the T-Rex, it's certainly more flexible. It's just 1.3 pounds and made of steel, so it's very durable. The CS7 comes with an input voltage switcher, you can take it anywhere in the world.
With 7 outputs, you have a lot of flexibility to experiment with different pedals. This isn't your grandma's vanilla 9v pedal power supply! One of the seven outputs is actually 18v! Four of the six remaining outputs have a 200 mA capacity and are switchable between 9v and 12v, so they can power just about anything on the market. The last two outputs are non-switchable 9-volt outputs that have an insane 500 mA capacity for even the most thirsty pedals. Strymon and Eventide users, rejoice!
The CS7 connects to an outlet using a super common 3-prong cable, so even if you lose it, someone's sure to have one lying around! This makes for headache-free gigging.
If you love the features of the CS7, but need to power a few more pedals, then check out the TrueTone CS12. It has 12 outputs to support even the largest of pedalboards.
For the guitarist who likes to experiment, the 10-output, fully-isolated MXR M238 Iso-Brick is a fantastic choice. Even those with the largest pedalboards will have no trouble powering their effects. Each output lights up blue to let you know if it's active, making for easy troubleshooting in case a wire accidentally disconnects from the power supply. It's extremely rugged thanks to a durable metal housing.
With 2 18v outputs, 4 9v outputs, and 2 variable voltage outputs, you have a ton of flexibility to experiment. The 2 variable voltage outputs allow you to adjust the voltage from 6v to 15V. This is great if you want to use less voltage with a certain pedal, which can give it a 'dying battery' sound that many vintage guitarists enjoy the sound of. Just be sure not to give your pedals more voltage than they can handle or you risk damaging them!
The MXR Iso-Brick is quite a small power supply. It's even smaller than the TrueTone CS7! The reason for this magic is in its design. Instead of having a built-in power transformer like other power supplies, it uses a wall-wart. This saves you space in the power supply itself at the cost of a larger power plug. This is useful if you want to mount the Iso-Brick under a pedalboard. Just be aware that the wall-wart could be a point of failure if you're frequently gigging. If you damage the wall-wart and don't have a backup, you're going to be up a creek without a paddle. We wish MXR chose to use a standard power cable, but the space savings is definitely a plus. Regardless, the MXR M238 Iso-Brick is still a fantastic choice.
The Walrus Audio Phoenix is the absolute coolest looking effects pedal power supply on the market. With this thing powering your board, you'll be set for any occasion. A ridiculous 15 outputs allow you to power the largest pedalboards - great for post-rockers and experimental musicians who have more pedals than they know what to do with. It's solid as heck and handmade in the USA.
You'll notice that the outputs are nicely grouped, making it super easy to find the correct output for each pedal on your board. Four of the 9V outputs supply 300 mA, which is perfect for thirsty pedals like Strymon or Eventide. Three of the outputs are voltage switchable. One output can be switched from 9v to 18v, and the other two can switch from 12v to 9v. It's a challenge to find a pedal the Phoenix can't handle!
The Walrus Audio Phoenix even comes with a courtesy outlet that lets you connect, well, anything to it! If you're searching for a place to charge your cell phone, and you're short on outlets, then you'll love this feature! Keep in mind that this is not a small pedal power supply, so you'll need a decent-sized board to comfortably hold it. It's about 10 inches wide, so measure your board to be sure the Phoenix will fit.
We covered a lot in this article. We've reviewed the basics of pedal power, how to avoid using wasteful batteries, getting rid of hiss, hum, and noise, and why you should go with an isolated power supply. we also took a look at some of the best power supplies available for every type of budget. Hopefully you learned a lot in this article. If you are unclear or need help with something, leave us a comment and we'll be sure to respond.