The Inner Bamboo Bass Instruments B-II Bass Preamp is a high-end preamp pedal for bass guitar. It is an analog circuit built to shape a bass signal before it reaches an amp or recording chain, sitting alongside other preamp pedals in the wider field of bass pedals1.
What it does
The B-II's main job is tone shaping. It carries a 3-band EQ covering Bass, Mid, and Treble, and each band has a dedicated frequency switch, which lets a player choose not just how much of each band is cut or boosted but where in the spectrum that band sits. Inner Bamboo describes this as allowing precise control over the tone1.
The pedal also runs an internal voltage boost from 9V to 18V. Inner Bamboo says this provides significant headroom and a clear, dynamic sound, meaning the circuit has more room before the signal compresses or distorts1.
Power
The B-II runs on 9V DC, center negative, and draws 230mA1.
At 230mA, the B-II draws more current than many pedals on a shared daisy-chain output can supply. Plan for a dedicated isolated outlet on the pedalboard power supply.
Demo
A demo of the B-II by GRACIAS.nagoya (JA) is available1.
Videos
Hiroshi Ishizuka Bass Channel
Questions
Does the Inner Bamboo B-II run on a battery?
The pedal runs on 9V DC, center negative, and draws 230mA. Because of that current draw, a standard daisy-chain supply or a battery is not a practical way to power it; use an isolated supply outlet rated for at least 230mA.
Sources (1)
- Bass Preamp by Inner Bamboo Bass Instruments, RockBoard PedalPedia, 2026