MXR M238 Iso-Brick Power Supply

Product Overview

The MXR M238 Iso-Brick Power Supply is a compact and robust unit designed to provide clean, isolated DC power to a wide range of guitar pedals and effects. It features 10 fully isolated outputs, effectively eliminating ground loop noise and ensuring optimal performance for your analog and digital effects. The Iso-Brick is built to withstand the rigors of gigging and offers versatile power options for various pedal types.

Figure 1: The MXR M238 Iso-Brick Power Supply, showing the unit, power adapter, and included patch cables.

Setup

1. Power Connection: Connect the included 18V power adapter to the "18V in" jack on the MXR Iso-Brick. Once connected, the blue indicator LED on the unit will illuminate, confirming that the unit is receiving power.
   

   Figure 2: Close-up of the Iso-Brick's output jacks and indicator LEDs.

2. Connecting Pedals: The Iso-Brick features 10 fully isolated outputs, each with specific voltage and current ratings.
   • Two 9V outputs at 100mA
   • Two 9V outputs at 300mA
   • Two 9V outputs at 450mA
   • Two 18V outputs at 250mA
   • Two variable outputs adjustable from 6V to 15V at 250mA

   Use the appropriate patch cables (three 6-inch MXR patch cables are included) to connect your pedals to the corresponding output jacks. Ensure that the voltage and current requirements of your pedals match the output specifications to prevent damage.

   

   Figure 3: An included 6-inch MXR patch cable.

3. Mounting: The compact design of the Iso-Brick allows for easy mounting on most pedalboards, helping to keep your setup tidy and efficient.

Operating Instructions

The MXR Iso-Brick is designed for straightforward operation. Once connected to power and your pedals, it provides stable and noise-free power. The individual indicator LEDs next to each output jack confirm power delivery to the connected pedal.

Variable Voltage Outputs

The two variable outputs (adjustable from 6V to 15V at 250mA) offer unique tonal possibilities. By adjusting the voltage, you can emulate the "voltage sag" effect of a drained battery, which is often sought after by musicians for vintage-style fuzz and overdrive tones. Use the small rotary knobs next to these outputs to precisely dial in the desired voltage.

Figure 4: Close-up of the variable voltage outputs with adjustment knobs.

Maintenance

The MXR Iso-Brick Power Supply is built for durability and requires minimal maintenance. To ensure its longevity and optimal performance:

• Keep the unit clean and free from dust and debris. Use a soft, dry cloth for cleaning.
• Avoid exposing the unit to extreme temperatures, humidity, or direct sunlight.
• Do not attempt to open the casing or modify the internal components, as this will void the warranty and could lead to electric shock.
• Ensure all cables are securely connected and not under undue strain.

Troubleshooting

If you encounter issues with your MXR Iso-Brick Power Supply, consider the following common troubleshooting steps:

• No Power Indicator Light:
  • Ensure the 18V power adapter is securely plugged into both the Iso-Brick and a working power outlet.
  • Verify that the power outlet is functional.
• Pedal Not Receiving Power:
  • Check that the patch cable is firmly connected to both the Iso-Brick output and the pedal's power input.
  • Confirm that the pedal's voltage and current requirements match the specific output used on the Iso-Brick.
  • Try a different output on the Iso-Brick or a different patch cable to isolate the issue.
• Excessive Noise/Hum:
  • While the Iso-Brick is designed to eliminate ground loop noise, ensure all other components in your signal chain (pedals, amplifier, cables) are functioning correctly and are not introducing noise.
  • Verify that all connections are secure.

If problems persist after attempting these steps, please contact MXR customer support for further assistance.

Specifications

Warranty and Support

For detailed warranty information and customer support, please refer to the official MXR website or contact your authorized dealer. Keep your proof of purchase for warranty claims.

This product is manufactured by Dunlop.