Jim Dunlop MXR Bass Compressor Pedal

The Bass Compressor provides recording-quality compression with Constant Headroom Technology and true bypass switching for keeping your low end tight and clean.

This pedal can be powered by a 9-volt battery, a Dunlop ECB003 9-volt adapter, or the DC Brick, Iso-Brick, and Mini Iso-Brick power supplies (not included).

Directions:

1. Run a cable from your bass to the Bass Compressor’s INPUT jack and run another cable from the Bass Compressor’s OUTPUT jack to your amplifier.
2. Set RELEASE, ATTACK, OUTPUT and INPUT controls to 12 o’clock and the RATIO control to 4.
3. Turn the effect on by depressing the footswitch.
4. Observe the METER display while playing normally and set the INPUT knob so that the first 3 to 7 green gain reduction LEDs light, clockwise to light more and counterclockwise to light less LEDs.
5. Rotate the OUTPUT knob clockwise to increase overall effect volume or counterclockwise to decrease it.
6. Rotate the ATTACK knob clockwise to increase reaction time of compression or counterclockwise to decrease it.
7. Rotate the RELEASE knob clockwise to increase the time it takes your signal to return to its uncompressed level or counterclockwise to decrease it.
8. Use the RATIO knob to select compression ratio. The 4 setting selects a 4:1 ratio, meaning that if the input level rises 4 decibelsabove threshold, the output level will only rise by 1 decibel. Therefore, gain has been reduced by 3 decibels. The 8 setting selects an 8:1 compression ratio, 12 selects 12:1, and 20 selects 20:1.

Input Impedance 1 MΩ
Output Impedance 600 Ω
Max Input Level +14 dBV
Max Output Level +8.5 dBV
Freq. Response
±1 dB, 20 Hz to 20 kHz
Noise Floor* -90 dBV
THD** >0.5%
Gain 31 dB
Compression Ratio
4:1, 8:1, 12:1, 20:1
Attack Time 20 µs to 800 µs
Release Time 50 ms to 1.1 s
Bypass True Hardwire
Current Draw
LEDs OFF 14 mA
LEDs ON 19 mA
Power Supply 9 volts DC