The MXR M81 Bass Preamp is a compact, studio-quality tone shaping tool designed to deliver clean, transparent sound in both live and recording environments. Housed in a pedalboard-friendly enclosure, this powerful preamp and direct box combo gives bass players precise control over their tone without adding unwanted coloration.

Featuring a highly flexible 3-band EQ with sweepable mids (250Hz–1kHz), the M81 allows you to fine-tune your sound with precision—whether you're enhancing clarity, tightening low end, or dialing in punchy mids. Separate input and output controls make it easy to match levels across different setups.

The built-in XLR direct output provides a pristine, studio-quality signal for sending directly to a PA system or recording interface. With a Pre/Post EQ switch, you can choose whether your EQ settings affect the direct signal, while the ground lift switch helps eliminate unwanted hum in live situations.

Powered by MXR’s Constant Headroom Technology™, this pedal maintains clear, distortion-free tone even at high output levels. Whether you're upgrading a passive bass, simplifying your live rig, or recording direct, the M81 Bass Preamp delivers professional-grade performance in a compact format.

• Model: MXR M81 Bass Preamp
• Type: Bass Preamp / DI Pedal
• EQ: 3-Band (Bass / Mid / Treble)
• Mid Control: Sweepable (250Hz – 1kHz)
• Controls: Input, Output, Bass, Mid, Treble
• Technology: Constant Headroom Technology™
• Outputs: 1/4" Output & XLR Direct Out
• Switches: Pre/Post EQ, Ground Lift
• Bypass: Buffered (True Bypass Option Internally)
• Power: 9V Battery or 9V DC Adapter (not included)
• Enclosure: Compact MXR (Phase 90 Size)

• Studio-quality direct box for live and recording use
• Clean, transparent tone that preserves your bass’s natural character
• High headroom design prevents clipping at higher volumes
• Ideal for passive and active basses