Here are some troubleshooting tips if you're experiencing feedback when using the EC-10M:
- Reduce the COMPRESSOR level. You can do so by turning the COMPRESSOR knob counterclockwise.
- Reduce the MIC VOLUME level, and/or the MIC GAIN (side panel) by turning their knobs counterclockwise.
- Lower the volume level on the amp if necessary.
- Confirm that the amplifier is not positioned directly behind or near the back of the cajon. If the amp is too close to the mic or angled at its direction, feedback is more likely to occur.