MXR M87 BASS COMPRESSOR

An MXR Compressor Designed for Modern Dynamic Control

With the M87 Bass Compressor, MXR aimed to bring rack-style dynamic processing reflexes to your pedalboard: fine adjustments, clean response, and comfortable headroom. Its CHT Constant Headroom Technology helps maintain a clear signal when playing hard, which is especially appreciated with active basses, pick playing, or percussive techniques. The idea is simple: preserve the instrument's character while securing level and consistency to better fit into the mix.

For Which Bassists and Playing Contexts?

The MXR M87 is aimed at bassists who want to control their dynamics without changing their sound. Whether you're looking for a bass compression pedal that can be subtle (just evening out volume differences) or, on the contrary, very shaping (to "lock" a line), it covers both approaches. It excels in funk and slap to tame peaks while preserving attack, in rock to stabilize volume and thicken presence, in pop to even out notes, and in metal to achieve tighter lows and a solid foundation. In recording, it facilitates more consistent and controlled takes; live, it reduces surprises and keeps your bass at the right level even when the intensity rises.

Settings, Ergonomics, and Key Points

The control panel is designed for speed and depth. The Input knob sets the incoming level and directly influences where compression begins to work. The Ratio determines the firmness of the effect: low for subtle smoothing, high for pronounced compression. The Attack and Release settings shape the playing feel: faster attack to tame an overly aggressive transient, or slower to retain more "punch" at the note's start; short release for a snappy response, or longer for a smoother, more consistent sustain. Finally, Output lets you balance the volume between compressed and bypassed sound (or even slightly boost the level if you want to cut through the mix).

The major practical advantage remains the gain reduction indicator: the 10 LEDs clearly show how much the pedal is compressing, making adjustments reliable even in a dark room or during a quick soundcheck. And thanks to the true hard bypass, when the pedal is off, you get a direct signal path, ideal for preserving the natural behavior of your bass and other effects.

Sound Character

The M87 is typically the compressor you choose when you want cleanliness and clarity. At moderate settings, it acts like a "stabilizer": notes sit better, sustain becomes more even, and lows stay solid without becoming muddy. It respects the instrument's personality (vintage passive bass, modern active bass, fingerstyle or pick playing) while providing a very reassuring sense of control. Pushing the ratio and input yields more pronounced, more "locked" compression, perfect for lines that need to remain consistent and present. Its responsiveness makes it easy to find the right balance between lively dynamics and perfectly controlled level.

Technical specifications

Effects	Bass, Compressor	EQ	No
Technology	Analog	Settings	input, release, output, attack, ratio
Format	Pedal	Use	Bass
Inputs	Jack	Color	White
Outputs	Jack	Power supply included	No
True bypass	Yes	Power supply	9V battery, DC 9 V
Display	Led

Category	Bass	Power	9V Battery or 9V DC
Effect	Compressor	Compatible power adapter (not included)	MDU ECB003E
Expression pedal	No	Required current	provide a 9V DC power supply capable of delivering at least 20 mA
Gain reduction indicator	Yes (10 LEDs)