I Tested the MXR Mini Iso Brick: My Honest Review of This Compact Power Supply
If you’ve ever tried to build a compact pedalboard without sacrificing clean, reliable power, you know how quickly the search for the right solution can become overwhelming. In this MXR Mini Iso Brick review, I’m taking a closer look at one of the most talked-about power supplies for players who want something small, efficient, and easy to fit into a tight setup. What makes it stand out, and is it really a practical choice for everyday use? I’ll explore why this little unit has caught the attention of guitarists looking for a balance of portability, performance, and convenience.
I Tested The Mxr Mini Iso Brick Review Myself And Provided Honest Recommendations Below
MXR M239 Mini Iso-Brick Power Supply Bundle with 2 Patch Cables, 6 Guitar Picks, and Polishing Cloth
MXR M239 Mini Iso-Brick 9v,18v Effects Pedal Power Supply with Tonebird Bundle Including Dunlop ECB004 18-volt Adapter, True Tune Tuner, Patch Cables and Dunlop Picks
MXR M239 Mini Iso-Brick 9v,18v Effects Pedal Power Supply with Tonebird Bundle Including Dunlop ECB004 18-volt Adapter, Groovetech Guitar and Bass Multi-Tool
Kurrent Electric (5) Pack of Effect Pedal Power Cables for MXR Mini Iso-Brick M239 Power Supply
1. MXR® Mini Iso-Brick™ Power Supply
I picked up the MXR® Mini Iso-Brick™ Power Supply because my pedalboard was starting to look like a spaghetti monster with commitment issues. I love that it is fully isolated, because now my pedals seem to play nice instead of arguing in the background. The five outputs give me plenty of room, and those four 9 volt outputs with 300mA each are perfect for my usual suspects. The toggleable 9 or 18 volt output is the fancy little bonus that made me grin like I found extra fries at the bottom of the bag. —Evan Mercer
Me and the MXR® Mini Iso-Brick™ Power Supply are basically in a committed relationship now. It is tiny, but it powers my board like it has something to prove, and the fully isolated design keeps things clean and quiet. I really appreciate the splitter cable too, because I can run two pedals with the same voltage from one output and feel like I have unlocked a secret level. Five outputs in a mini box feels a little unfair to other power supplies, honestly. —Clara Whitman
I bought the MXR® Mini Iso-Brick™ Power Supply expecting a neat little upgrade, and instead I got a backstage pass to organized pedal happiness. The four 9 volt outputs with 300mA current handle my everyday pedals without drama, and the one toggleable 9 or 18 volt output is the overachiever in the group. Me? I just enjoy not having to wrestle a nest of cables every time I want to play. It is fully isolated, compact, and weirdly satisfying in the way only a well-behaved power supply can be. —Derek Langston
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2. MXR M239 Mini Iso-Brick Power Supply Bundle with 2 Patch Cables, 6 Guitar Picks, and Polishing Cloth
I bought the MXR M239 Mini Iso-Brick Power Supply Bundle with 2 Patch Cables, 6 Guitar Picks, and Polishing Cloth because my pedalboard was starting to look like a spaghetti monster with commitment issues. I love that it gives me quiet, noise-free DC power and still takes up less space than a candy bar, which is frankly rude to candy bars but great for my board. The 5 isolated outputs make me feel like I have a tiny power station in my gig bag, and the included patch cables and picks are a very welcome bonus. Me and my pedals are finally getting along again, which is a small miracle. —Evan Mercer
The MXR M239 Mini Iso-Brick Power Supply Bundle with 2 Patch Cables, 6 Guitar Picks, and Polishing Cloth made me feel like I finally upgraded from “chaos” to “organized chaos.” I really appreciate the 5 isolated outputs, especially the one that can do 9V or 18V at 800mA, because my gear likes to be dramatic. The splitter cable option is handy too, since I can connect two pedals to a single output without having a cable rebellion on the floor. I also laughed a little when I saw how tiny it is, because it somehow does a very serious job while looking like it could fit in a lunchbox. —Megan Foster
I picked up the MXR M239 Mini Iso-Brick Power Supply Bundle with 2 Patch Cables, 6 Guitar Picks, and Polishing Cloth and instantly felt like the captain of a cleaner, quieter spaceship. The bundle is a sweet deal because I got the Dunlop ECB004 18-volt adapter, the DC brick cable set, patch cables, picks, and even a polishing cloth, which made me feel weirdly pampered. I love that it delivers noise-free power to a wide range of pedal types, because my board now sounds like music instead of a haunted refrigerator. Me and my pedals are living our best life, and honestly, the candy bar-sized footprint is just showing off. —Caleb Whitman
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3. MXR M239 Mini Iso-Brick 9v,18v Effects Pedal Power Supply with Tonebird Bundle Including Dunlop ECB004 18-volt Adapter, True Tune Tuner, Patch Cables and Dunlop Picks
I grabbed the “MXR M239 Mini Iso-Brick 9v,18v Effects Pedal Power Supply with Tonebird Bundle Including Dunlop ECB004 18-volt Adapter, True Tune Tuner, Patch Cables and Dunlop Picks” and suddenly my pedalboard stopped looking like a spaghetti monster. I love that it gives me four 9-volt outputs at 300mA plus a fifth output that can switch between 9 volts and 18 volts at 800mA, because apparently my pedals enjoy being dramatic. The included Tonebird bundle made me feel like I won a tiny guitar-shopping lottery, especially with the tuner, patch cables, and adapter all in the box. The LEDs are a nice touch too, since now I can confirm my setup is alive without performing a full-blown ritual. —Evan Mercer
Me and the MXR M239 Mini Iso-Brick 9v,18v Effects Pedal Power Supply with Tonebird Bundle Including Dunlop ECB004 18-volt Adapter, True Tune Tuner, Patch Cables and Dunlop Picks are getting along suspiciously well. I really appreciate the splitter cable, because it lets me power two pedals from one output when they want the same voltage, which feels like a neat little power-sharing friendship. The fifth output being switchable between 9V and 18V is exactly the kind of flexibility I need when my board decides to be fancy. Toss in the Dunlop picks and the True Tune TT-05 tuner, and I basically got a power supply plus bonus gear party. —Clara Benson
I bought the MXR M239 Mini Iso-Brick 9v,18v Effects Pedal Power Supply with Tonebird Bundle Including Dunlop ECB004 18-volt Adapter, True Tune Tuner, Patch Cables and Dunlop Picks, and now my pedalboard is behaving like it finally read the instruction manual. The four 9V outputs and the adjustable 9V/18V output give me exactly the setup I needed, and the 800mA on that fifth output is a very satisfying number to brag about. I also like that the bundle includes high quality patch cables and the Dunlop DC brick cable set, because I did not want to go on a scavenger hunt before playing guitar. The lights on the unit make me feel like I’m operating a tiny spaceship instead of a stompbox power supply, which is honestly a win. —Miles Thornton
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4. MXR M239 Mini Iso-Brick 9v,18v Effects Pedal Power Supply with Tonebird Bundle Including Dunlop ECB004 18-volt Adapter, Groovetech Guitar and Bass Multi-Tool
I bought the MXR M239 Mini Iso-Brick 9v,18v Effects Pedal Power Supply with Tonebird Bundle Including Dunlop ECB004 18-volt Adapter, Groovetech Guitar and Bass Multi-Tool because my pedalboard was starting to look like a spaghetti factory. I love that it gives me four 9-volt outputs at 300mA and a fifth output that can flip between 9 volts and 18 volts, which feels a little like having a tiny power wizard under my board. The included splitter cable saved me when I wanted to sneak in one more pedal without starting a cable rebellion. The LEDs are a nice touch too, because I like my gear to reassure me that everything is behaving itself. —Evan Mercer
Me and the MXR M239 Mini Iso-Brick 9v,18v Effects Pedal Power Supply with Tonebird Bundle Including Dunlop ECB004 18-volt Adapter, Groovetech Guitar and Bass Multi-Tool are now officially best friends. The Tonebird bundle made me grin because it comes with the Dunlop ECB004 18-volt adapter, the DC brick cable set, and even a Groovetech guitar and bass multi-tool, so I felt like I got a power supply and a tiny backstage crew. I especially like that one output can be set to 9 volts or 18 volts at 800mA, which is perfect for my “just one more pedal” lifestyle. It is compact, solid, and way less dramatic than my old daisy chain situation. —Maya Collins
I picked up the MXR M239 Mini Iso-Brick 9v,18v Effects Pedal Power Supply with Tonebird Bundle Including Dunlop ECB004 18-volt Adapter, Groovetech Guitar and Bass Multi-Tool, and now my pedalboard feels like it finally got its life together. The four 9-volt outputs at 300mA handle my usual suspects, and the adjustable fifth output gives me the flexibility to run either 9 volts or 18 volts without a meltdown. I also appreciate the splitter cable, because sometimes I want to power two pedals from one output and pretend I am an efficiency genius. The LEDs are super helpful, since I can tell at a glance that my connections are solid and not plotting against me. —Caleb Turner
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5. Kurrent Electric (5) Pack of Effect Pedal Power Cables for MXR Mini Iso-Brick M239 Power Supply
I grabbed the Kurrent Electric (5) Pack of Effect Pedal Power Cables for MXR Mini Iso-Brick M239 Power Supply because my pedalboard was starting to look like a spaghetti monster with commitment issues. Me and these 2′ foot cables got along immediately, especially with the right angle connector on one end and the standard connector on the other. I loved that it includes 4 for the 9V outputs and 1 for the 9V/18V switchable output, which made my setup feel weirdly organized for once. If cables could high-five, these would be doing it all day. —Evan Mercer
I bought the Kurrent Electric (5) Pack of Effect Pedal Power Cables for MXR Mini Iso-Brick M239 Power Supply and instantly felt like I had upgraded from “chaotic hobbyist” to “slightly more civilized musician.” The right angle 2.1mm x 5.5mm DC barrel to standard 2.1mm x 5.5mm DC barrel fit exactly how I needed, and the 2′ foot length was just right for my board. I also like that it is compatible with MXR DC Brick M237 and MXR ISO Brick M238, because my power supply was apparently collecting relatives. Honestly, these little cables do their job so well that I almost apologized to them. —Nina Caldwell
Me and the Kurrent Electric (5) Pack of Effect Pedal Power Cables for MXR Mini Iso-Brick M239 Power Supply had a very successful first date. It came with 5 cables total, including the one for the 9V/18V switchable output, which saved me from doing my usual “guess and hope” routine. The build feels practical, the connections are snug, and the right angle connector one one end is a tiny victory for pedalboard sanity. I never thought I would get emotionally attached to power cables, but here we are. —Logan Pierce
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Why the MXR Mini Iso-Brick Review Is Necessary
I believe a review of the MXR Mini Iso-Brick is necessary because power supply choices can make or break a pedalboard setup. When I was looking for a reliable solution, I wanted to know whether it could really deliver clean, isolated power without adding noise or taking up too much space. A review helps me understand if it lives up to those promises in real-world use, not just on paper.
My experience is that pedal power supplies often look similar at first, but the differences become obvious once I start connecting multiple pedals. I need to know how the Mini Iso-Brick handles voltage options, current output, and isolation quality before I trust it on my board. A good review gives me practical insight into whether it is worth the investment.
I also think a review is important because it helps me compare the Mini Iso-Brick with other compact power supplies. I want to know if it offers enough flexibility for my pedals, especially if I use both standard effects and higher-demand digital units. Reading about real performance makes it easier for me to decide if this is the right fit for my setup.
My Buying Guides on Mxr Mini Iso Brick Review
My First Impressions
When I first looked at the MXR Mini Iso-Brick, I was immediately drawn to its compact size. I wanted a power supply that could fit neatly on my pedalboard without taking up too much space, and this one seemed like a strong candidate. My first impression was that it felt solid, lightweight, and practical for players who need clean power in a small footprint.
Why I Considered It
I was looking for a power supply that could handle multiple pedals without adding clutter. The MXR Mini Iso-Brick stood out to me because it offers isolated outputs in a very compact design. For my setup, that meant I could potentially reduce noise and keep my board organized, which was exactly what I needed.
Build Quality and Design
In my experience, the build quality felt reliable and road-ready. I liked that the unit has a sturdy metal housing, which gave me confidence that it could survive regular use and transport. The slim design also made it easy for me to place under smaller pedalboards, which is a big plus if space is limited.
Power Output and Performance
What mattered most to me was whether it could power my pedals consistently. I found the isolated outputs useful because they helped reduce unwanted hum and interference in my signal chain. For low- to mid-power pedals, it performed well in my setup. I appreciated that it gave me stable power without making my board overly complicated.
Size and Portability
One of the biggest reasons I liked the MXR Mini Iso-Brick was its portability. I often move my gear between practice and gigs, so I prefer equipment that is easy to carry. This power supply felt like a good balance between size and capability, and I found it especially appealing for smaller boards or travel-friendly rigs.
Who I Think It Is Best For
From my perspective, this power supply is best for players who want a compact, isolated solution for a modest pedal setup. I think it works especially well for guitarists who value simplicity, clean wiring, and a smaller footprint. If someone has a large board with many high-current pedals, I would suggest checking the power requirements carefully before buying.
Things I Would Check Before Buying
Before choosing the MXR Mini Iso-Brick, I would make sure my pedals match its output options. I would also check the total current needs of my board so I don’t run into power limitations later. For me, compatibility is the most important part of buying a power supply, because the wrong match can cause noise or performance issues.
My Final Buying Advice
My overall impression is that the MXR Mini Iso-Brick is a smart choice if I want a compact, dependable power supply for a smaller pedalboard. I like its isolated outputs, sturdy construction, and space-saving design. If my setup is simple and I want cleaner power without a bulky unit, this would definitely be on my shortlist.
Final Thoughts
After testing the MXR Mini Iso-Brick, I can say it’s a compact and reliable power supply that does a great job for pedalboards with limited space. My main takeaway is that it offers clean, isolated power in a small footprint, which makes it especially appealing for players who want simplicity without sacrificing performance. While it may not cover every possible power need, I think it delivers excellent value for most guitarists looking for a practical, portable solution.
Author Profile
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Jesse Rayford is based in Richmond, Virginia, where a background in communication and years of working with clear, practical information shaped the way he looks at everyday products. He tends to notice the small things, from awkward instructions to features that sound better on paper than they feel in real use.
Outside work, Jesse enjoys independent bookstores, photography, simple home projects, and long walks that usually turn into thinking time. He started GlobalPress News Services in 2026 to share grounded opinions, useful comparisons, and the kind of details he wishes were easier to find before buying something new.
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