My amp is an Acoustic B200H with the matching 4x10. The amp by itself is loud and bassy, but the mid range was always kind of muddy. I used a late 70's Mann P-Bass copy and an Ibanez SR405QM. I couldn't get the sound I was looking for.
So I got an MXR Bass DI+. This pedal is exactly what I needed. It has a gate that stops most feedback and all hum, the tone is shaped perfectly for what I needed. The dirty effect is ok, kind of like a Boss Distortion. Dial it back a little and it adds some grit. Plus it is a killer DI, way better than the DI on the amp.
I just got the Morley Cliff Burton Tribute Power Fuzz Wah. I haven't been able to use it with my set up yet, just at the house with my little amp. I have the original Telco Morley Power Fuzz Wah, the late 70's model with the electro optical sensor. I freaking loved that pedal!! I used to play in a Brutal Truth style grindcore band. Then, my set up was PBass tuned to B > ProCo Rat > Morley Power Fuzz Wah > DOD Analog Delay > Ampeg SVT > Apmeg 8x10. MONSTER tone.