Abstract: A digital recording device (110) is portable and battery powered, designed particularly for operation with a guitar (115) and other stringed musical instruments (115a) whether fitted with magnetic pick-ups or not. The device (110) is sufficiently small and light weight to be carried by the musical instrument's jack socket (105) while being used. When not in use, the device is small enough to he considered “pocket sized”. The device uses a novel microphone (915) technique to receive and digitise acoustic signals produced by a musical instrument, or other source of analogue data, and store it numerically, for subsequent transfer in digital file format via a wireless connection (1055) and/or a Universal Serial Bus port. The device (110) offers a means of digitally recording music directly at the instrument, for subsequent playback or transfer to another device or piece of equipment.