Boss LM-2 Limiter

The Boss LM-2 Limiter is an analog limiter pedal, a form of compressor that clamps the loudest peaks of your playing so volume stays even. RockBoard's product listing classifies it as a compressor effect and gives its circuit type as analog¹.

What it does

As a limiter, the LM-2 sits in the compressor family: it reduces the level of notes that cross a set threshold, which tames peaks and can raise the apparent sustain of quieter playing. The pedal's control set centers on a threshold knob. On the LM-2B version reviewed by OvniLab, the reviewer Cyrus Joaquin Heiduska found that "the only way to get less squashing from the LM-2B is to raise the threshold (turning the knob clockwise)"². In other words, the knob sets how hard the pedal clamps: higher threshold, gentler compression; lower threshold, more of the signal caught and squeezed.

Tone and circuit

OvniLab's review also describes what the circuit does to frequency balance. With the Enhance control off, the pedal "significantly roll[s] down the high frequencies in a long wide slope", a roll-off the reviewer notes is even stronger than on Boss's LMB-3, which can read as a bass boost depending on output level². At the heart of the circuit, the review identifies a dbx 1252 VCA chip, the voltage-controlled amplifier that performs the gain reduction².

Power

The LM-2 runs on 9V DC, center negative, and draws 12mA, figures given in RockBoard's listing, which also links the English owner's manual hosted by Roland¹. At 12mA it is a light load on a pedalboard power supply.

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