The 2-Band Boost-Only Onboard Preamp with Stacked Treble/Bass Pot from aguilar features a boost-only design that gives you the tone-shaping benefits of active electronics without losing the inherent sound of the instrument. The OBP-1's discrete all-FET circuitry features up to 18 dB of boost at 40 Hz and 4 kHz, creating a sonic environment high in dynamic headroom and low in noise.