Some Ibanez basses with Humbucking pickups are equipped with a so called "3-way Power Tap Switch", e.g., SR300E or SR375EF. This switch provides three modes with different sounds[1]:
- Tap mode: Single coil mode
- Series mode: humbucking mode ("normal" mode, since the pickups are humbuckers)
- Power tap mode: combines heights of a single coil pickup and the "fat bottom" of a humbucking pickup
While in "Single Coil" mode the tap signal of a humbucking pickup is connected directly to its ground signal, in "Power tap mode" this connections goes through a high pass filter (a filter, that lets only through frequencies above a certain threshold); this high pass filter consists of a capacitor and a resistor. The purpose of this is that for high frequencies the humbucking pickups act like single coil pickups, while for low frequencies the pickups act like humbucking pickups. However, the noise produced by single coil pickups will get through the high pass filter.[2][3]