MXR M87 Bass Compressor

MXR M87 Bass Compressor: Detailed Control for Demanding Players

The MXR M87 Bass Compressor enters a crowded market offering a level of hands-on compression tuning that is rarely seen in compact pedals. Since its launch, bassists and even some guitarists have gravitated toward the M87 for its transparency, robust build, and adaptability. At just under $200, it sits at a professional price point, but a look beneath the hood and at real-world feedback shows why it remains a staple on pedalboards.

Feature Overview and Build Quality

Aimed specifically at electric bass, the M87 is housed in a sturdy metal enclosure and features Constant Headroom Technology, which prioritizes clear, uncolored tone even at higher input levels. It operates off a standard 9V battery or the Dunlop ECB-003 power adapter (not supplied). Five compact control knobs, output, input, attack, release, and ratio, provide precise tweaking potential. The unit includes a true bypass switch and two LED displays: one for pedal status and one ten-segment chain to show realtime gain reduction.

• Controls: Output, input, attack (20 microseconds to 800 microseconds), release, and compression ratio (4:1, 8:1, 12:1, 20:1).
• Visual feedback: Ten-segment LED meter for gain reduction, status light for on/off.
• Construction: Heavy-duty metal chassis, reliably protecting the internals during gigging and travel.
• Power: Runs on standard 9V battery or regulated adapter, battery compartment requires a screwdriver to access.

Compression, Tone, and Transparency

Where the M87 stands out is in its transparency. With well-set parameters, the pedal operates in the background, gently leveling playing dynamics without compromising the natural timbre of your bass. Several users note that the effect is only truly evident when the pedal is suddenly disengaged, translating to professional-level subtlety. Those seeking overt "squeeze" or pumping effects may need to experiment with more aggressive settings or consider another pedal altogether.

Attack and release controls are notably flexible for a pedal format. The attack parameter allows for both very fast and quite slow response, shaping whether the compressor clamps onto the note instantly (for slap or funk, or to control aggressive fingerstyle), or lets the transient through for a punchier or more expressive sound. The release control widens the expressive range, from super tight to smooth and sustained. The ratio switch jumps rapidly between moderate (4:1) to extreme (20:1) limiting, but some advanced users wish for more granular adjustment here.

Metering and Usability

The gain reduction LED strip deserves special mention for its real-world utility. Many owners report that visualizing compression in real-time accelerates the fine-tuning process, turning guesswork into objective changes. However, the control layout can take some getting used to, especially as input and attack reside on the right, output and release on the left. Some also mention that the small size of the knobs makes precise adjustments challenging for larger hands, and reproducing settings on the fly is less intuitive due to the lack of visible graduations.

For those new to studio-grade compression parameters, the learning curve is real. However, once you have found your settings, the pedal responds faithfully session after session. The pedal emits minimal noise, and there's no audible click or pop when engaging/disengaging, critical for live players and recording.

Versatility and Applications

Although designed for bass, the M87 has proven itself on electric and acoustic guitars in a variety of genres. Its wide frequency response (20 Hz to 20 kHz) allows anything from fat, glued-in-place funk bass to bright, percussive country guitars. In band settings, the pedal brings out missing punch in weaker pickups or helps even the level swings inherent in playing techniques like slapping, tapping, or expressive fingerstyle. That said, some find the pedal a little clinical, favoring transparent consistency over warmth.

Real-world reliability is generally solid. The pedal holds up through gig stress, pedalboard abuse, and years of rehearsals. There are scattered reports of units developing delayed start-up issues (LEDs taking minutes to extinguish, with reduced output until stabilizing), but these appear to be rare, and the three-year warranty from major retailers is valued.

Comparison and Value

Compared to more basic compression pedals (such as "one knob" designs), the M87 delivers a suite of features more reminiscent of studio rack units than typical stompboxes. Despite competing options like the Keeley Bassist (noted for simplicity and ruggedness), the M87 wins for sheer control and the educational benefit of a visual metering strip. The lack of a dedicated threshold control is remedied by the input/output arrangement, but may take a minute to adapt to for those used to studio hardware or digital plug-ins.

Summary: Who is the MXR M87 For?

If you are looking for transparent, flexible compression that can elevate your bass (or guitar) to polished, consistent output, the MXR M87 is a leading choice. It rewards players who want comprehensive parameter control and aren't afraid to tweak. While not the cheapest pedal, the features and build justify the investment, and even pros with experience on studio compressors find it meets their expectations. Beginners may face a steep learning curve, but once dialed in, the M87 becomes a mainstay on any serious musician's board.

• Strengths: Complete parameter control, high transparency, versatile for multiple instruments, rugged build, LED meter for clarity.
• Possible drawbacks: Steep learning curve, knobs can feel small, occasional quality control concerns, AC adapter not included.

Verdict: The MXR M87 Bass Compressor brings near-studio-grade compression to a compact pedal. For those willing to explore its extensive tweaks, tonal consistency and dynamic control are within easy reach.