Preamp "Pop" Noise

[Chris Wohlfeil]

Hi Ken and Everybody else,

I have a problem with the preamp on my Ken Smith Bass:
When going from passive to active, and pushing down the volume knob, I get a very loud popping noise. I get this noise even when I turn down the volume of the bass, so I actually have to turn down the volume on the amp, on order to avoid this.
Any Ideas what this could be and how I can solve the Problem?

Many thanks,

Chris.