ok I have a reggie hamilton jazz bass.. I like it very much, it's got a bone nut and badassII and I like everything except.. for the preamp.. the freqs on the standard preamp are made for a 5 string not a 4 string so the bass is useless.. when I drop tune to B.. it's awesome but in standard tuning it sucks.. so I'm thinking of getting an aguilar OBP-3.. Bass control: plus/minus 18 dB @ 40 Hz. Mid control: plus/minus 16 dB @ 400Hz or 800 Hz. User selectable frequency center. Treble control: plus/minus 16 dB @ 6.5 KHz. Input impedance: 1 meg ohm Output impedance: 100 ohm 9 or 18 volts operation. Additional 6dB with 18 volts. Distortion: .019 into 10k ohm load Noise: -95 dBm unweighted. Battery life: 324 hours then I'm thinking of getting the mid selector switch replaced by a push/pull pot in the mid control and getting an active/passive swtich.. and I'm getting an 18 volt for 6 more db of headroom.. so what do you guys think ?