First of all, I am a newbie and have never used any effect pedal. I have been considering the tech 21 VT bass just to have a bit of fun and get some variation on tones. However, I see people use the VT bass with other pedals (such as overdrive etc). My question is - why do you need to use an overdrive with the VT Bass? Does the VT bass give you the overdrive effect already? Thanks.