7
MicroBass-III Series
Rear Panel Controls
1 Power On/Off Switch:
Press in to turn the amplifier
on, out to turn it off. Power/Protect LED is on when the
amplifier is on.
2 AC Receptacle:
The power cord is detachable and
plugs in here.
3 Speaker Output:
Power amp ¼” jack outputs. It
delivers 150W into 4 Ohms or 100W into 8 Ohms.
4 Internal Speaker On/Off Switch (Combo Only):
Turns the internal speaker off for private headphone lis-
tening or to allow the internal power amplifier to drive
an external speaker load of 4 ohms.
5 Effects Return Jack (MBE Only):
When the Return
jack is used, the Effects Loop is in series. All of the signal
goes through the Effects Loop.
6 Effects Send Jack (MBE Only):
Send and return
jacks provided for the insertion of effects after the EQ,
but before the boost section.
7 Footswitch Jack (MBE Only):
Use the RF2 Foot-
switch to turn on/off the Boost and Chorus effects.
8 Direct Outputs (MBE Only):
A pair of electronically
balanced low Z outputs, for sending a separate left and
right mic level signal to a PA system. Pre/Post Switch-
able.
9 Ground/Lift (MBE Only):
This switch disconnects
the ground on the balanced, XLR output to eliminate
hum and buzz when connecting to equipment that is on
a different ground system.
10 Direct Out Mode Switch (MBE Only):
When Mode
1 is selected, XLR Right is Mono Post and XLR Left is
Mono Pre. When Mode 2 is selected, the Direct Outs are
Post Left/Right for Stereo Chorus output.
11 Line Out:
Provides a line level signal (post Boost)
for interfacing with outboard power amplifiers or an
external DI Box.
Internal/External Speakers
The MB-III Series combos feature one 8 Ohm, 12”
low resonance speaker, which delivers surprising
low-end response and volume for it’s size. While it
works great for electric bass, the MB Series combo is
particularly well suited for acoustic upright bass.
Driving External Cabinets:
The MB Series combo electronics are identical to
the MB Series heads and are rated for the same
maximum power output and speaker load (150W
into 4 Ohms or 100W into 8 Ohms). Maximum
power is achieved by connecting one 8 Ohm ex-
tension cabinet such as the 112MBX in addition to
the combo’s internal 8 Ohm speaker load. To drive
more than one extension cabinet, the combo’s in-
ternal speaker can be disconnected by pressing the
Internal Speaker switch on the back panel. Below
is a detailed description of the maximum loads the
combos can drive.
Maximum Recommended Load:
Internal Speaker On:
One 8 Ohm extension cabinet.
Internal Speaker Off:
One 4 Ohm, or Two 8 Ohm extension cabinets.
Rear Panel & Speakers
1 2 3 5 4 6 3 7 8 8 9 10 11
1 2 3 4 3 11
