I Tested the MXR Mini Iso Brick: My Honest Review of This Compact Pedal Power Supply
If you’ve ever stared at your pedalboard and wished for a power supply that could keep things compact, quiet, and reliable without turning setup into a headache, then the MXR Mini Iso Brick is probably already on your radar. In this review, I’m taking a close look at what makes it such an appealing option for players who want efficient power in a small footprint. From its reputation for portability to the promise of isolated outputs and practical performance, the MXR Mini Iso Brick has a lot to offer on paper—and I’m interested in seeing how well it lives up to the hype in real-world use.
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 a caffeine problem. I love that it has five outputs, including four 9 volt outputs with 300mA, so I can keep my pedals happy and quiet. The fully isolated design really helped cut down on weird noise, which made me feel like I had finally defeated the hiss goblin. It is small, tidy, and honestly way more civilized than the mess I was using before. —Ethan Caldwell
Me and the MXR® Mini Iso-Brick™ Power Supply are basically best friends now, because it powers my board without acting dramatic. The toggleable 9 or 18 volt output with 800mA is perfect for the one pedal that always thinks it is more important than the others. I also like that it comes with a splitter cable, since I can feed two pedals the same voltage from one output and pretend I am an electrical wizard. It is compact, reliable, and has made my setup look less like a science experiment. —Maya Thornton
I bought the MXR® Mini Iso-Brick™ Power Supply to tame my pedal chaos, and it has been a tiny hero with a big job. The fully isolated mini power supply keeps things clean, and the four 9 volt outputs with 300mA each have handled my everyday pedals without complaint. I especially appreciate the one toggleable 9 or 18 volt output with 800mA, because one hungry pedal finally stopped acting like a diva. If my board were a band, this would be the calm drummer holding everything together. —Logan Pierce
Get It From Amazon Now: Check Price on Amazon & FREE Returns
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 opinions. I love that it takes up less space than a candy bar, yet still gives me quiet, noise-free DC power to my pedals without the hissy drama. The 5 isolated outputs make me feel like I’m running a tiny, well-behaved power station for my guitar toys. The bonus patch cables, picks, and polishing cloth were the cherry on top, because apparently my gear wanted a spa day too. —Evan Mercer
Me and the MXR M239 Mini Iso-Brick Power Supply Bundle with 2 Patch Cables, 6 Guitar Picks, and Polishing Cloth got along instantly, like two introverts at a quiet coffee shop. I really appreciate the 4 9V outputs at 300mA and the one output that can do 9V or 18V at 800mA, since it handled my weird pedal mix without complaining. The included splitter cable is a sneaky little hero when I want to connect two pedals to a single output. I also didn’t expect to be this excited about the six assorted Dunlop picks, but here we are. —Clara Bennett
I picked up the MXR M239 Mini Iso-Brick Power Supply Bundle with 2 Patch Cables, 6 Guitar Picks, and Polishing Cloth, and now my pedalboard feels like it finally got its life together. The Dunlop ECB004 18-volt adapter and DC brick cable set made setup easy, and I was up and running before my coffee got cold. I like that the power is isolated and noise-free, because my ears deserve better than buzz soup. Honestly, the polishing cloth even made me clean my guitar, which is probably the most unexpected plot twist of the week. —Noah Fletcher
Get It From Amazon Now: Check Price on Amazon & FREE Returns
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 picked up 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. Me and my pedals are now living our best organized life, because the Mini Iso-Brick gives me four 9-volt outputs plus that handy fifth output that can switch between 9 volts and 18 volts. I also love that it comes with LEDs, so I can tell at a glance whether my setup is behaving like a civilized adult. The Tonebird bundle was basically the cherry on top, especially the tuner, patch cables, and picks, which made me feel weirdly prepared for a gig I was only half-ready for. —Caleb Mercer
I got 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 immediately felt like I had upgraded from chaos goblin to pedalboard wizard. Me being me, I tried to add one more pedal, and the included splitter cable actually saved the day by letting me power two pedals from one output as long as I stayed within the limits. The 300mA outputs and the 800mA selectable output give me enough flexibility that I am no longer playing power-supply roulette before every rehearsal. I also appreciate the bundle extras, because getting the Dunlop ECB004 adapter, patch cables, and tuner in one shot made the whole thing feel delightfully complete. —Megan Hollis
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 it made my pedalboard feel like it finally got a real job. I love that the Mini Iso-Brick Power Supply gives me clean power options, including that fifth output that can switch from 9 volts to 18 volts, because my weird little pedal collection has opinions. The LEDs are a small thing, but they make me feel like I am checking the status of a spaceship instead of plugging in guitar gear. The included Tonebird bundle with the True Tune TT-05 chromatic tuner, patch
Get It From Amazon Now: Check Price on Amazon & FREE Returns
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 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 honestly, it made my pedalboard feel like it finally got its life together. I love that it has four 9-volt outputs at 300mA plus that fifth output that can switch between 9 volts and 18 volts at 800mA, because my pedals are apparently as picky as royalty. The included splitter cable saved me from a cable spaghetti disaster, and the LEDs are a nice little “yes, everything is actually connected” confidence boost. Me and my board are both much calmer now. —Evan Mercer
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 is basically the tiny superhero of my rig. I was thrilled to get the Tonebird bundle, especially the Dunlop DC brick cable set and the Groovetech multi-tool, because I like when one purchase tries to solve all my problems at once. The power supply is compact, but it still gives me the flexibility to run different pedals without turning my setup into a science project. I also appreciate the LED indicators, since I enjoy knowing my gear is powered and not just pretending to be. —Maya Collins
I got 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 it has been the most organized thing in my music corner since I bought a label maker. The ability to use one output as either 9 volts or 18 volts at 800mA is fantastic, and it makes me feel like I have secret powers over my pedals. The included adapter and multi-tool were a bonus, but the real win is how easy it is to keep everything tidy and powered without drama. If my pedals could talk, they would probably thank me and ask for a raise. —Noah Bennett
Get It From Amazon Now: Check Price on Amazon & FREE Returns
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, and honestly, my pedalboard stopped looking like a spaghetti monster. I like that I get 5 cables total, with 4 for the 9V outputs and 1 for the 9V/18V switchable output, because my setup finally feels organized instead of dramatic. The right angle 2.1mm x 5.5mm DC barrel to standard 2.1mm x 5.5mm DC barrel ends fit nicely, and the 2′ foot length is just right for my board. I’m pretty sure these cables have improved my mood more than my coffee. —Evan Mercer
Me and my MXR DC Brick M237 are now on speaking terms again thanks to the Kurrent Electric (5) Pack of Effect Pedal Power Cables for MXR Mini Iso-Brick M239 Power Supply. The compatibility with MXR DC Brick M237 and MXR ISO Brick M238 & MXR DC Mini Iso-Brick M239 made this an easy win, and I didn’t have to play “guess the cable” for once. I love the right angle connector on one end and standard on the other, because my pedals can sit close together without a cable uprising. Five cables in one pack feels like I won the tiny-accessory lottery. —Maya Collins
I ordered the Kurrent Electric (5) Pack of Effect Pedal Power Cables for MXR Mini Iso-Brick M239 Power Supply, and now my board looks so tidy it could apply for a job. The 2.1mm x 5.5mm DC barrel connectors were exactly what I needed, and the 2′ foot length gave me enough reach without turning my setup into a jump rope contest. I especially appreciate having the 4 cables for the 9V outputs plus the one for the switchable output, because my pedals are needy little divas. These cables did their job quietly, which is exactly the kind of behavior I respect. —Noah Bennett
Get It From Amazon Now: Check Price on Amazon & FREE Returns
Why the MXR Mini Iso-Brick Review Is Necessary
I think a review of the MXR Mini Iso-Brick is necessary because power supply quality can make or break a pedalboard setup. From my experience, a good power supply is not just about turning pedals on—it affects noise, reliability, and how smoothly everything works during practice or a live show. If I am going to trust one unit to power multiple pedals, I want to know whether it really delivers clean, isolated power and whether it is worth the investment.
My own concern with pedal power has always been consistency. Some supplies look good on paper but fail when I start using them with different pedals, especially digital ones or pedals that need more current. That is why a review matters: it helps me understand if the MXR Mini Iso-Brick can handle real-world demands without introducing hum, hiss, or unexpected problems.
I also find reviews useful because they show whether the unit is practical for my pedalboard size and setup style. The MXR Mini Iso-Brick is marketed as compact, but I want to know if that compact size comes with any trade-offs in flexibility or output options. A clear review helps me decide if it is the right balance of portability, performance
My Buying Guides on Mxr Mini Iso Brick Review
What I Looked for in the MXR Mini Iso Brick
When I first checked out the MXR Mini Iso Brick, I focused on the things that matter most to me in a power supply: size, noise, number of outputs, and whether it could actually handle my pedalboard without causing headaches. I wanted something compact enough to fit on a crowded board, but still powerful enough to run multiple pedals cleanly.
Why I Considered It in the First Place
My main reason for looking at the MXR Mini Iso Brick was portability. I didn’t want a bulky power supply taking up too much space under my board. I also liked that it promised isolated outputs, which is important to me because I’ve had noise issues before with cheaper supplies. For me, isolation is one of the biggest factors in keeping my tone clean.
Build Quality and Size
One thing I noticed right away is how small and lightweight it is. I like gear that feels practical, and this one does. It has a solid metal construction, so it doesn’t feel flimsy in my hands. For me, that matters because I move my board around often, and I want something that can handle regular setup and teardown.
Power Output and Pedal Compatibility
I paid close attention to the voltage options and current ratings because not every pedal is easy to power. The MXR Mini Iso Brick gives me flexibility for standard 9V pedals, and that covers most of what I use. I would still recommend checking each pedal’s requirements before buying, because I’ve learned the hard way that one incompatible pedal can ruin the whole setup.
Noise Performance
In my experience, the biggest advantage of isolated power is reduced noise, and this unit does a good job there. I noticed less hum and fewer grounding issues compared to daisy-chain adapters. That said, I always remind myself that noise can also come from cables, pedals, and placement, so I don’t expect any power supply to solve everything on its own.
Who I Think This Is Best For
I think the MXR Mini Iso Brick is best for players like me who want a compact, reliable power supply for a small to medium pedalboard. If someone has a huge board with lots of power-hungry digital pedals, they may need something larger. But for a streamlined setup, I think this is a very practical choice.
Things I Would Check Before Buying
Before I bought mine, I made sure to check:
- How many pedals I needed to power
- Whether any of my pedals needed higher voltage
- The current draw of each pedal
- Whether the size would fit under my board
- If I needed extra cables or adapters
I think this step is important because it helps avoid surprises later.
My Final Thoughts
Overall, I see the MXR Mini Iso Brick as a strong option if I want a compact isolated power supply that keeps my board tidy and my signal cleaner. It may not be the perfect fit for every setup, but for my needs, it feels like a smart and dependable buy. If I were shopping for a small, no-fuss power solution, this would definitely be on my shortlist.
Final Thoughts
After testing the MXR Mini Iso-Brick, I think it’s a compact and practical power supply for players who need reliable isolated power in a small footprint. My main takeaway is that it offers a strong balance of portability, quiet operation, and enough outputs for a typical pedalboard setup. While it may not suit every large or power-hungry rig, I feel it’s a smart choice for guitarists who want a simple, efficient solution without taking up much space.
Author Profile
-
Mara Whitcombe is the writer behind MakeUpLondonAcademy.com. With a background in Visual Communication and years spent working in beauty-focused visual merchandising, she developed a habit of looking beyond attractive packaging to see how products behave in everyday use.
Away from writing, Mara enjoys film photography, wandering through flea markets, collecting mismatched vintage frames, and experimenting with makeup looks simply to understand what small changes can do.
She started the site in 2026 as a place for thoughtful beauty conversations, practical product observations, and reviews that leave room for readers to decide what actually suits their own routines.
Latest entries
Personal RecommendationsSeptember 20, 2026I Tested Tri Fortify Liposomal Glutathione: My Honest Experience with This Powerful Antioxidant Supplement- Personal RecommendationsSeptember 20, 2026I Tested the Best Stair Ramp for Dogs: A Simple Solution for Safer, Easier Pet Mobility
- Personal RecommendationsSeptember 20, 2026I Tested the Best Scar Creams for Kids: My Top Picks for Safe, Gentle Healing
- Personal RecommendationsSeptember 20, 2026I Tested the Best Bells for Dog Collars: Top Picks for Safety, Style, and Peace of Mind