Ground_Lift,_Post/Pre,_Direct_Out; Effects_Loop:_Send_&_Return; Footswitch - Mesa/Boogie Big-Block 750 Owner's Manual

reAr PANeL CONTrOLS:

GROUND_LIFT,_POST/PRE,_DIRECT_OUT:_

750 enhancement so that an engineer can create their own sound with your unprocessed signal at the console. This is very handy
for sound reinforcement applications as the sound you use on stage may be too big with enhanced low end for a large venue house
application.
GROUND_LIFT:_This switch removes the circuit-to-chassis ground connection from the XLR jack. Leave it in the grounded position
(switch down) normally unless you experience a hum when connecting to a console. If you do experience a hum when connecting
the XLR Output to a console, try lifting the ground (switch up) on the circuit. This will usually (but not always) remedy most ground
loop type noise from the signal path.
Sometimes it may also be necessary to lift the A.C. Cable Ground also by using a 3-2 ground adapter to achieve a quiet signal
path.
NOTE: Ground loops can occur in many places in a complex signal path. The DIRECT OUTPUT GROUND LIFT switch is not a cure-
all and therefore should not be expected to remedy every type of ground related problem.
EFFECTS:
These two jacks provide an interface for external signal processors and they access a point between the preamp and
power section. This wiring scheme creates a Series Effects Loop that is well matched to the input and output impedance of most good
quality processing devices. The jacks used in the loop are switching-type jacks - meaning that when nothing
is inserted into either SEND or RETURN_the preamp signal bypasses the jacks. When cables are inserted
M-PULSE BIG BLOCK 750
SIMUL STATE BASS AMPLIFIER
the signal path is interrupted and sent through the EFFECTS_LOOP.
TUBE DRIVEN-MOSFET POWER
EFFECTS
Because the loop is wired in series, anything you do to the signal here will affect the entire sound of the
amplifier. Therefore we suggest using only the highest possible quality of processing devices and the best
possible low capacitance cables of the shortest possible length.
RETURN SEND
NOTE: Cable lengths of 1 foot are best with 3 feet being about the longest desirable length. Using longer interface cables in the series
loop will introduce unwanted capacitance and begin to roll off top end and attack.
To_use_the_EFFECTS_LOOP:
1_) Connect the SEND jack to your processors' INPUT.
2_)_Connect the RETURN jack to your processors' OUTPUT.
3_) Adjust the dry/wet blend with your processors' MIX ( WET OUTPUT ) control.

FOOTSWITCH:

This 1/4" stereo jack accepts the stereo phone plug from the included BIG BLOCK Footswitch. Connecting the
FOOTSWITCH via this jack allows remote activation of the OVERDRIVE and TUNER MUTE features.
GROUND
LIFT
DIRECT OUTPUT
LEVEL
HANDBUILT IN PETALUMA , CALIFORNIA
(Continued)
TUBE DRIVEN-MOSFET POWER
The TUNER MUTE feature can only be activated when the FOOTSWITCH is con-
EFFECTS
nected.
RETURN SEND
FOOT
TUNER
SWITCH
(Continued)
PRE gives you just the sound of your instrument and no BIG BLOCK
PAGE_9