Feature:1. Onboard bass frequency regulator potentiometer can make a relatively wide adjustment, so that subwoofer can be blend in the midtotreble harmoniously without a sense of violation2. Dual 5532 2.0 full‑tone + 0.1 bass structure can control the volume of each channel of 2.0+0.1, adjustable bass frequency phase with powerful bass3. Both full frequency and bass output signals have independent interfaces, which is very convenient4. Support both DC 12‑30V and AC 9‑20V input voltage, powerful and practical5. Made of high quality material with fine workmanship to guarantee a stable performanceSpecification:Item Type: Preamp boardChip Model: NE553278M12Architecture: Dual 5532 2.0 full tone + 0.1 bassFrequency Range: Full tone 20-20KHz / bass 20-200HzFeatures: 2.0+0.1 controllable volume, adjustable bass frequency and phase.Package List:1 x Preamp Board