
Congratulations on the purchase of your new M-188 MXR Bass
Auto Q stomp box! MXR effects have been favored by professional guitarists for decades. While other effects have come
and gone, MXR’s keep getting the job done … with bulletproof
construction, quiet, reliable switching and tasteful, musically
inspired tone shaping.
DESCRIPTION
• Authentic Crybaby®Bass Wah tones and Q control
• Sensitivity circuit delivers effects at any volume
• Blendable LFO shimmer goes from tremble to shriek
• Fully adjustable transition from wah to LFO
• Indestructible, die-cast zinc housing
POWER
The MXR M-188 Bass Auto Q uses one 9-volt battery. The battery access is
through the bottom of the pedal. The Bass Auto Q uses the Dunlop ECB03
Adapter (ECB03E for Europe), a 9-volt DC regulated AC adapter. Plug polarity
is positive on the barrel and negative in the center. Note:Battery must be
installed to operate the Bass Auto Q unless an AC adapter is used.
M-188 bassautoQ

CONTROLS
Footswitch toggles Effect On/Bypass (red LED indicates on).
Range Knob controls frequency floor of effect.
The “Q” Knob adjusts the intensity of the wah effect.
Volume Knob controls overall effect volume (inactive in Bypass mode).
Decay Knob controls dropoff decay of wah effect.
Blend Knob controls mix between wah and shimmer.
Rate Knob controls the speed of the shimmer effect.
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B
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DIRECTIONS
To set up the MXR M-188 Bass Auto Q, plug your instrument into the Input
jack and your amplifier into the Output jack. Be sure the Footswitch is in
the Off position (red LED off), or Bypass mode. Set all knobs except Blend
to their straight up, or 12 o’clock positions, and set the Blend Knob all the
way off (counterclockwise). Then turn the effect on with the Footswitch
(red LED on). Play some notes while switching the effect on and off, adjusting the Volume Knob until the volume is approximately equal in both modes.
This is a good starting point for volume; though you may want to readjust
volume after making other settings.
Adjust the Range Knob to select the frequency floor, or how low the
effect should go. Play both single notes and chords to hear how your sound
is affected.
The “Q” Knob adjusts the intensity of the wah effect by adjusting the
peak of the wah filter. The higher and narrower the peak goes (“Q” knob
clockwise), the more intense the wah effect sounds. The Volume Knob is
interactive with other controls, so that you may want to readjust it after
each new tone setting. The only other knob that impacts the wah effect is
Decay; when the Blend Knob is all the way off (counterclockwise), the
Decay Knob controls only the dropoff of the wah effect.
The final two knobs, Rate and Blend, control the “variable shimmer”
effect that is unique to the Auto Q. Turn the Blend Knobup to introduce
the shimmer effect and control which effect is more dominant, the auto
wah (counterclockwise) or shimmer (clockwise). Straight up mixes both
effects equally. Adjust the Rate Knob for the desired speed of the shimmer effect.
When the shimmer effect is blended in, the Decay Knob controls not
only the dropoff of the wah, but also the transition from wah to shimmer.
You can start a note with wah, and end it with a shimmering flourish for
sounds you can’t get anywhere else!

SAMPLE SETTINGS
To help you get started using your M-188 MXR Bass Auto Q stomp box,
we’ve provided a roadmap of knobs and switch settings used by top artists.
You’re set to play with any of these settings or find your favorite and experiment from there.
DUNLOP MANUFACTURING, INC. P.O. BOX 846 BENICIA, CA 94510 U.S.A.
TEL: 1-707-745-2722 FAX: 1-707-745-2658 WWW.JIMDUNLOP.COM
JUSTIN MELDAL-JOHNSEN / BECK
“STUPID DECAY”
LEE SKYLAR / LA STUDIO SESSION PLAYER
“MUTT”
CHRIS CHANNEY / ALANIS MORRISSETTE
“BOOTSY”
MARK BROWNE / LA STUDIO SESSION PLAYER
“70’S VIBE”
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