A problem with my special project

Hi all. I made a special cane for somebody, and I'm having trouble with it. I thought one of you could tell me what I might be doing wrong here.

It's a purpleheart and maple electric dulcimer built around a wooden walking stick. It includes a bass guitar pickup, a 2.5 watt amp module, and a miniature 3 watt speaker. The amplified sound is distorted, like if you were using a "fuzz box" with it. But I want a clean, amplified sound to come from it. I tried lowering the pickup and setting the amp trimpot adjustment to "clean", with no improvement. is the sound a result of the speaker being too close to the pickup, or something else?