This item was purchased and used by my child during their student days. After graduating in 2009 and becoming a working adult, they left it at home while living in company housing and apartments. It has remained unused since then, stored in the attic storage room. The storage room has become cramped due to an increase in stored items, so I am selling it to organize the space. I connected an electric bass and tested its functionality, confirming that sound output was working. Turning the three knobs allows for adjusting the sound output level in response to the bass strings' vibrations. However, turning the knobs when the strings are in a state of disrepair produces scratchy noises. After adjusting the knobs and fixing their positions, there are no noticeable noises during playing, so it should be suitable for practice.