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MXR M238 ISO Brick Review

A compact, quiet, flexible, and stress-reducing power supply.

Discussing power supplies is about as diverting as watching shower mold spread. But the pedal-powering possibilities of MXR’s versatile and powerful new m238 ISO Brick make the issue much more fun to think about.

To start, it makes pedalboard layout easy. The recessed, right-angled barrel connecter means there’s no DC cord hogging space. There are 10 outputs, each fully isolated to eliminate noise. (Yes, this unit is very quiet) Two 9V 450 mA outputs accommodate most power-hungry DSP-type pedals. There are also two 100mA and two 300mA 9V outputs—plus a real treat: two 6-15V variable voltage outputs for approximating voltage sag or increasing headroom. Each output also has an LED that glows blue when you’ve got a proper connection.

The inclusion of adaptors for UK/EU/Australian power and the fact that the ISO Brick makes voltage conversion a no-worry proposition are significant bonuses. I used it for shows in the US, UK, and Europe, and setup was as simple as clipping on the appropriate attachment and plugging in­—priceless convenience from a power supply brimming with stress-reducing features.

Test gear: Boss DD-5, TR-2, and CS-3, Strymon Flint, Stomp Under Foot Civil War, Electro-Harmonix Pedal Bag


Compact. Super quiet isolated power sources. Multiple voltage and current settings (including higher ones that accommodate DSP pedals.) Click-in adapters for overseas use.



MXR M238 ISO Brick Power

Ease of Use: