M281 Thump Bass Preamp

The MXR M281 Thump Bass Preamp is a compact pedal that combines the tone- sweetening magic of the Echoplex Preamp with a three-band EQ and midrange frequency adjustment, offering versatile tonal shaping capabilities for bass players. The pedal features the following technical specifications:

- Input Impedance: 1 MΩ
- Output Impedance: 100 Ω
- TONE CONTROLS:
- Bass: +15/-7 dBV at 40 Hz
- Mid: ±16 dBV at 1 kHz
- Treble: ±10 dBV at 4 kHz
- Frequency Sweep: 250 Hz to 1 kHz
- Noise Floor: -95 dBV
- Bypass: True Hardwire
- Current Draw: 9 mA
- Power Supply: 9 Volts DC (powered by Dunlop ECB003 9-volt adapter or DC Brick, Iso-Brick, and Mini Iso-Brick power supplies)

The pedal's design includes separate Input and Output level controls, a 3-band EQ section with sweepable midrange, and a footswitch for toggling the effect on/off (indicated by a blue LED). The Thump Bass Preamp is suitable for various use-cases, such as punching up a solo, boosting the signal in a live mix, or adding edge to the sound of a passive bass.

The pedal is designed to be powered by a 9-volt adapter or compatible power supplies and cannot be powered by a battery. It is housed in a compact MXR mini housing, providing bass players with a versatile and space-saving solution for enhancing their tone.