On most recorders, there is a volume control knob or button. This knob or button will typically have a range of settings, from low to high. To increase the volume, turn the knob or button clockwise. To decrease the volume, turn the knob or button counterclockwise.
Some recorders also have a volume control in the software that accompanies them. This software can typically be found on the computer or device that is used to record. To change the volume in the software, open the software and go to the settings menu. There should be a volume control option in the settings menu. Adjust the volume control to your desired level.
If the recorder does not have a volume control, you may be able to change the volume by using the device's headphone jack. To do this, connect a pair of headphones to the headphone jack and adjust the volume on the headphones.
If the recorder is not connected to a computer or device, you may be able to change the volume by disconnecting and reconnecting the power cable. This may reset the recorder to its default volume setting.
If none of these methods work, you may need to contact the manufacturer of the recorder for assistance.