The MXR M81 Bass Preamp at a glance:

• Bass preamp in pedal format
  
• Analog circuitry with constant headroom technology
• Input control for adjusting the signal strength at the input of the pedal
• Output knob for adjusting the pedal volume
• Active 3-band EQ with selectable center frequency for the mid control
• Balanced XLR Direct-Out with pre/post switch and ground lift
• Bypass footswitch
• Internal DIP switches for setting different bypass options for the Direct-Out and jack output
• Compact metal chassis
• Powered by 9V battery or optional AC adapter
  

Compact Preamp for E-Bass with flexible EQ and Direct-Out

The MXR M81 Bass preamp comes in a handy pedal format and turns out to be a secret weapon for studio and stage with its flexible and top-class sound.

Analog circuitry with Constant Headroom technology

Thanks to the analog circuit with Constant Headroom Technology, the MXR M81 delivers a crystal-clear Bass sound without distortion or unwanted noise. The input control determines the signal strength at the input of the circuit, so that even powerful active basses can be used with M81 Preamp without any problems.

3-band EQ with semi-parametric mids

For precise tweaking of the Bass sound, MXR's M81 Bass Preamp features an active 3-band equalizer that boosts or cuts bass and treble up to 18 dB. The center frequency of the midband can also be tuned between 250 Hz and 1 kHz to define the character of the Bass sound.

Direct Out

In addition to the classic jack output, the MXR M81 Bass Preamp naturally features a balanced XLR Direct Out, which can be used to feed the Bass sound directly into a mixing console or audio interface. The Pre/Post switch determines whether the processed preamp signal is output or the pure input signal.