MESA BOOGIE Owner's Manual
Greetings from the Home of Tone Congratulations on your choice of the Big Block 750 as your Bass amplifier and welcome to the MESA/Boogie family! As a discriminating player you probably know that you have purchased the most comprehensive instrument for amplifying Bass that is available. What you might not realize is that this entitles you to all the experience, resources and commitment our twenty-five years of service to musicians world wide has to offer.
PRECAUTIONS & WARNINGS Your MESA/Boogie Amplifier is a professional instrument. Please treat it with respect and operate it properly. USE COMMON SENSE AND ALWAYS OBSERVE THESE PRECAUTIONS: WARNING: Vacuum tube amplifiers generate heat. To insure proper ventilation always make certain there is at least four inches (100mm) of space behind the rear of the amplifier cabinet. Keep away from curtains or any flammable objects. WARNING: Do not block any ventilation openings on the rear or top of the amplifier.
Table of Contents Precautions Overview 0 1/2 FRONT PANEL: INSTRUMENT INPUT TUNER CONTROLS: OVERDRIVE GAIN BASS PASSIVE MID ACTIVE MID FREQUENCY TREBLE MASTER O.D.MASTER POWER SWITCH 3 3 3/4 4 4/5 5 5 6 6 6 7 7 REAR PANEL: FUSE A.C.
Operating Instructions Overview: Congratulations on your choice of the M-PULSE BIG BLOCK 750 as your amplifier and welcome to the MESA/Boogie Family! First we would like to thank you for choosing us as your amplifier company. This is something we never take for granted and you will come to find that we are here to help you sound your best should you ever need help.
Overview: (Continued) Looking at the Front Panel, it is apparent how logically the controls are laid out before you, creating a simple and intuitive platform for expression. However, don’t let this simplicity deceive you as to the incredible shaping power of this preamp. The tone controls are voiced such that minimal shaping is needed to achieve a warm musical blend, yet should you want to create your own signature sound, they can take you anywhere you wish to go quickly and effortlessly.
FRONT PANEL CONTROLS: INPUT: This jack is the instrument INPUT which feeds the first tube in the all-tube preamp of the BIG BLOCK. It is set up with enough headroom to handle both passive and active style instruments. For active instruments you may find yourself running the GAIN control somewhere between 10:00 and 2:00 for optimum headroom. If you do hear a soft clip creeping in at higher settings, don’t worry, this is the beauty of a tube front end.
FRONT PANEL CONTROLS: (Continued) OVERDRIVE: (Continued) Note that the GAIN control is still active when the OVERDRIVE is switched into the signal path. The GAIN control is wired in series with the OVERDRIVE and therefore, it can be used to further fine-tune the amount of overdrive present in the mix. The effect of the GAIN control is more apparent at the lower region of the OVERDRIVE control, where sweeping the GAIN is very noticeable. At higher OVERDRIVE settings it has a fairly diminished effect.
FRONT PANEL CONTROLS: (Continued) BASS: (Continued) This type of broad band, active rotary control makes it possible to achieve bass characteristics far beyond that of a conventional passive type control. It can increase the low end to an almost absurd level and with a flick of the wrist, dip it to near transitor radio skinniness. Needless to say, with any control this powerful a certain amount of finesse must be applied to achieve musical results.
FRONT PANEL CONTROLS: (Continued) FREQUENCY: This control determines the frequency range that the ACTIVE MID control will cut or boost. As mentioned earlier, it covers a broad range that sweeps from the low midrange region to the lower treble frequencies. The control sweeps from 200Hz on the low side to 2Khz on the high side - with 340 Hz riding the center, straight up at 12:00 on the control.
FRONT PANEL CONTROLS: (Continued) O.D. MASTER: This control, like the OVERDRIVE, is designed to help you think outside the box. It provides an independent volume control for the OVERDIVE mode, allowing you to preset the level of the overdriven sound and footswitch to it for specific parts. The O.D. MASTER is only active when the Footswitch is connected to the Rear Panel FOOTSWITCH jack.
REAR PANEL CONTROLS: REAR VIEW: Big Block 750 CAUTION:Unplug power before removing fuse or bolts holding chassis FUSE FUSE POWER 120 V~ 60 Hz 15 A POST PRE M-PULSE BIG BLOCK 750 SIMUL STATE BASS AMPLIFIER LEVEL SLAVE OUT TUBE DRIVEN-MOSFET POWER GROUND LIFT EFFECTS SPEAKER OUTPUT FUSE 15A SLO BLO DIRECT OUTPUT LEVEL RETURN SEND FOOT SWITCH TUNER SUGGESTED LOAD 2 OHMS MINIMUM HANDBUILT IN PETALUMA , CALIFORNIA FUSE: This is the A.C. Mains Fuse for the BIG BLOCK 750.
REAR PANEL CONTROLS: (Continued) GROUND LIFT / POST & PRE / DIRECT OUT: (Continued) PRE gives you just the sound of your instrument and no BIG BLOCK 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.
REAR PANEL CONTROLS: TUNER: FOOT SWITCH (Continued) This Rear Panel auxiliary TUNER output is wired in parallel with the Front Panel TUNER output. This provides for Rear Panel interfacing of rack mount tuners, where it is preferable to have all wiring stay in the rear of a rack system. TUNER The Footcontroller MUTE switch activates the MUTE feature in both Front and Rear outputs simultaneously.
FACTORY SAMPLE SETTINGS SAMPLE SET #1: Round Warm R & B S I M U L S T A T E TM OVERDRIVE INPUT ENGINEERING B A S S A M P L I F I E R GAIN BASS PASSIVE-MID ACTIVE-MID FREQUENCY TREBLE MASTER O.D.MASTER TUNER AC OFF MUTE OVERDRIVE 5 - STAGE VACUUM TUBE AMPLIFIER SAMPLE SET #2: Scoopy Slap S I M U L S T A T E TM OVERDRIVE INPUT ENGINEERING B A S S A M P L I F I E R GAIN BASS PASSIVE-MID ACTIVE-MID FREQUENCY TREBLE MASTER O.D.
PERSONAL SETTINGS SHEET S I M U L S T A T E TM OVERDRIVE INPUT ENGINEERING B A S S A M P L I F I E R GAIN BASS PASSIVE-MID ACTIVE-MID FREQUENCY TREBLE MASTER O.D.MASTER TUNER AC OFF MUTE OVERDRIVE 5 - STAGE VACUUM TUBE AMPLIFIER S I M U L S T A T E TM OVERDRIVE INPUT ENGINEERING B A S S A M P L I F I E R GAIN BASS PASSIVE-MID ACTIVE-MID FREQUENCY TREBLE MASTER O.D.
DIAGNOSING PREAMP TUBE PROBLEMS: At some point it is quite possible that you will experience some kind of minor pre-amp tube noise. Rest assured - this is no cause for alarm and you can take care of the problem yourself in a matter of minutes by simply swapping tubes. It is always a good idea to keep at least a couple of spare pre-amp tubes on hand at all times to insure uninterrupted performance.
S I M U L S T A T E TM ENGINEERING B A S S A M P L I F I E R OVERDRIVE INPUT SWITCH pt# 600631 ALL FRONT PANEL KNOBS SAME part # 408114 FRONT VIEW: Big Block 750 PASSIVE-MID BASS GAIN ACTIVE-MID FREQUENCY TREBLE MASTER O.D.
MESA BOOGIE The Spirit of Art in Technology Thank you for trusting MESA/Boogie to be your amplifier company and we wish you many years of toneful enjoyment from this handbuilt all tube instrument.
The Spirit of Art in Technology (707) 778-6565 FAX NO.
