Firmware for the Synthesis Technology E520 Hyperion Stereo Effects Processor

This is firmware version 1.3b for the E520. The final published firmware version on the Synthesis Technology website is version 1.3a, released in August 2023. Since then a minor issue was reported with the Wet/Dry mix control which is addressed by this late release in March 2025.

Find out more detail about the E520 at the Synthesis Technology website.

1. Go to the view page <-- by clicking this link.
2. Click on the "download raw file" button to begin downloading.

1. Copy the firmware file “e520_fmw.bin” onto a FAT32 formatted SD card of 32GB or less.
2. Turn off the E520 and insert the SD card into your E520’s Micro SD card slot.
3. While holding in the encoder button, turn on the E520. When you see the blue bootloader screen. If your firmware file was properly copied to the SD card then you will be given the choice to install it.
4. Select “Yes” to begin installation. This will take some time but you will see progress information.
5. After flashing completes push the encoder button to restart the system.