Mesa/Boogie Simul State M-PULSE Owner's Manual
OOGIE
B
M
ESA
Owner's Manual
Greetings from the Home of Tone
Congratulations on your choice of the M-PULSE 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. Our responsibility is to help you sound great! So, if at any time you feel
you need help or direction, we are here for you...a phone call away.
FRONT PANEL:
REAR PANEL:
Precautions 0
Overview 1/2
Instant Gratification 2
Helpful Hints 3
Instrument Inputs: ACTIVE & PASSIVE 4
GAIN 4
BASS 5
MID 5
TREBLE 5/6
PARAMETRIC EQUALIZER 6
GAIN CONTROL: Parametric EQ 6/7
FREQUENCY CONTROLS: Parametric EQ 7
COMPRESSOR 8
THRESHOLD 8
RATIO 8/9
MAIN Output 9
SOLO Output 9
POWER SWITCH 9
FUSE 10
A.C. RECEPTACLE 10
SLAVE OUT 11
SPEAKER OUT 11
DIRECT OUT: LEVEL, POST / PRE, GROUND LIFT and XLR jack 11
EFFECTS: SEND, RETURN, MIX and PROGRAN switch 12
TUNER OUTPUT 12
FOOTSWITCH 12
FACTORY SAMPLE SETTINGS 13/14
TUBE NOISE & DIAGNOSING PRE-AMP TUBE PROBLEMS 15
PERSONAL SETTING PAGES 16/17
PARTS SHEET 18
Table of Contents
READ AND FOLLOW INSTRUCTIONS OF PROPER USAGE.
IMPORTANT SAFETY INSTRUCTIONS
Read these instructions.
Keep these instructions.
Heed all warnings.
Follow all instructions.
Do not use this apparatus near water.
Clean only with dry cloth.
Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with one wider than the other. A grounding type plug
has two blades and a third grounding prong. The wide blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet,
consult an electrician for replacement of the obsolete outlet.
Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
Only use attachments/accessories specified by the manufacturer.
Unplug this apparatus during lightning storms or when unused for long periods of time.
Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug
is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally,
or has been dropped.
To insure proper ventilation always make sure there is at minimum four inches (101.6mm) of space behind the rear of the apparatus. The ventilation should not
be impeded by covering the ventilation openings with items, such as newspapers, tablecloths, curtains, etc. Do not impede ventilation by placing objects on top
of the apparatus which extend past the rear edge of its cabinet.
No naked flame sources, such as lighted candles, should be placed on the apparatus.
The apparatus shall not be exposed to dripping or splashing and no objects filled with liquids, such as vases, shall be placed on the apparatus.
WARNING: To reduce the risk of fire or electric shock, do not expose this apparatus to rain or moisture.
The AC plug is the mains disconnect. The plug should remain accessible after installation.
WARNING: EU: permission from the Supply Authority is needed before connection.
WARNING: Always make sure proper load is connected before operating the amplifier. Failure to do so could pose a shock hazard and may result in damage
to the amplifier.
Do not expose amplifier to direct sunlight or extremely high temperatures.
Always insure the amplifier is properly grounded. Always unplug AC power cord before changing fuse, tubes or removing chassis. Use only same type and
rating when replacing fuse.
Avoid direct contact with heated tubes. Keep amplifier away from children.
To avoid damaging your speakers and other playback equipment, turn off the power of all related equipment before making the connections.
Do not use excessive force when handling buttons, switches and controls. Do not use solvents such as benzene or paint thinner to clean the unit.
Always connect to an AC power supply that meets the power supply specifications listed on the rear of the unit. Export models: always insure unit is wired for
proper voltage. Make certain grounding conforms with local standards.
YOUR AMPLIFIER IS LOUD! EXPOSURE TO HIGH SOUND VOLUMES MAY CAUSE PERMANENT HEARING DAMAGE!
Your Mesa/Boogie Amplifier is a professional instrument. Please treat it with respect and operate it properly.
OVERVIEW:
FRONT VIEW :
M- PULSE 600
ACTIVE
PASSIVE
INPUT
GAIN BASS MID TREBLE
FOUR - STAGE VACUUM TUBE PREAMPLIFIER
ON
POWER
ON
FS
OFF
0 db 0 0 0 0
40 Hz 120 400 1.4K 6K
SEMI - PARAMETRIC EQUALIZER
30 90 250 900 4K
SIMUL STATE POWER
THRESHOLD RATIO MAIN SOLO
COMPRESSION MASTER VOLUMES
ON
FS
OFF
ENGINEERING
S I M U L S T A T E B A S S A M P L I F I E R
TM
Congratulations on your choice of the M-PULSE as your Bass amplifier. This latest offering is our most comprehensive amplifier
for electric bass and it brings together both new and old technology, solid state and vacuum tube design to create an instrument of
unparalleled performance and soulful sound.
M-PULSE amplifiers start with an all-tube pre-amp for the most musical response and this feeds the three standard rotary tone
controls BASS, MID and TREBLE. Most first time players comment that we could have stopped right there after hearing the sweet,
tight, huge sound from this first section of the M-PULSE pre-amp. But that’s just the beginning!
From there, signal is routed to an ultra-powerful 5 Band Parametric Equalizer that has been optimized for the frequencies found on
today’s 5 & 6 string instruments. A bandwidth from 30Hz to 12Khz is found on the 5 frequency controls and each overlaps to assure
a smooth transition between bands. The 5 GAIN controls allow a boost and cut of 15db in either direction to provide 30db of band
specific shaping power. This EQ can be assigned On, Off or Footswitch, which is activated when the M-PULSE Footcontroller is
connected. Build a rich, complex, sound utilizing the parametric as your main voice or, add the EQ for a footswitchable solo or slap
sound to an already amazing fundamental tone...either way this 5 Band EQ is a great addition you will come to find invaluable.
Next in the signal path is a new improved Compressor that features both THRESHOLD and RATIO controls. First included on our
M-2000 Bass amplifier, this updated version allows for much greater fine-tuning of the dynamics. The THRESHOLD control is extremely
sensitive to your attack and can be set for either subtle or dramatic compression effects. The RATIO control allows for anything from
slight dynamic trimming all the way to a hard knee squash with a range from 1:1 to Infinity. The Compressor is also assignable On,
Off or Footswitch giving you the choices of active or inactive all the time or triggering it remotely during a performance as an effect.
After the Compressor we jump over to the Output section that serves up the mighty SIMUL STATE power with its awesome 600 (or
360) watts of rich, tube-driven MOSFET tone. This innovative circuit combines the best attributes ot tube and solid state technology
to arrive at a magical blend that breathes and yet, tracks tight while producing massive power.
This power is interfaced to you via a pair of Output controls that serve as overall MASTER VOLUMES. These are MAIN and SOLO and
PAGE 1
the two astound bassists much as they did when we began including them on our guitar amplifiers. The logic is in their names MAIN
REAR VIEW :
M- PULSE 600
Instant Gratification:
OVERVIEW:
Continued
INPUT
GAIN BASS MID TREBLE
FOUR - STAGE VACUMM TUBE PREAMPLIFIER
ON
POWER
ON
FS
OFF
0 db 0 0 0 0
40 Hz 120 400 1.4K 6K
SEMI - PARAMETRIC EQUALIZER
30 90 250 900 4K
SIMUL STATE POWER
THRESHOLD RATIO MAIN SOLO
COMPRESSION MASTER VOLUMES
ON
FS
OFF
INSTANT GRATIFICATION (Parametric EQ Optional)
ENGINEERING
ACTIVE
PASSIVE
CAUTION
:
Unplug power
before removing fuse or
bolts holding chassis
POWER FUSE
12A
SLO
BLO
120 V~
60 Hz
12 A
F
U
S
E
F
U
S
E
SENDRETURN
SLAVE OUT
SUGGESTED LOAD
4 OHMS (2 OHM MINIMUM)
SPEAKER OUTPUT
FOOT
SWITCH
LEVEL DIRECT OUT
POST
PRE
LEVEL
GROUND
LIFT
0% 100%
F.S.
ON
EFFECTS
TUNER
OUTPUT
WARNING
:
To reduce risk of fire or
electric shock, replace fuse with
same type and rating only. Do not
expose this unit to rain or moisture.
WARNING
:
To reduce risk of fire or electric
shock, Do not remove cover. No userserviceable parts inside. Refer
servicing to qualified personnel.
M-PULSE TM SIMUL STATE BASS AMPLIFIER
TUBE DRIVEN-MOSFET POWER
HANDBUILT IN PETALUMA, CALIFORNIA
and SOLO. When players get this scheme they say “why hasn’t there always been two”. There will be from now on as imitators follow,
but right now we are giving you another footswitchable feature in the form of this SOLO control. This is an additional Master pot wired
in parallel with the MAIN Output and it allows a footswitchable SOLO boost. This feature lets you step out for a showcased part or
allows you to compensate for a sound that has a lower output due to either notching in the Parametric EQ or Compression or both.
Looking to the Rear Panel you can see that all your interfacing needs are well provided for. A dedicated TUNER Output is provided
for
tuning without having to disconnect. The Parallel Effects Loop and MIX control provides seamless interfacing of all your outboard
processing. The Loop is also footswitchable allowing you to call up your effects on the fly.
A Balanced XLR DIRECT OUTPUT and LEVEL control is provided with both Post and Pre settings to capture your sound through
house main or recording consoles. In addition a SLAVE Output with LEVEL control is provided capturing both pre-amp and power
section in a padded format. This enables you to use additional power for large venues or for deriving a post signal for effects to be sent
to additional amplifier(s) in a 1 dry / 1 wet scenario. And finally, 2 SPEAKER OUTPUTS are provided to harness the robust output of
the M-PULSE power amp. With this pair of jacks almost any speaker cabinet or combination of cabinets can be accommmodated.
Now that we have covered the basics of your new M-PULSE, let’s connect up the A.C. and your favorite cabinet and Bass and give
this instrument of fundamental enlightenment a listen with a quick reference setting.
Now that you have had a listen to your M-PULSE, here are a few quick tips to help you in case you don’t have time to read the rest
of this manual right now.
PAGE 2
HELPFUL HINTS:
1. Connect your A.C. Power Cable to a grounded outlet. Avoid ground lifts (3 to 2 prong adapter) whenever possible.
2. The optimum speaker load for your M-PULSE is 4 Ohms. You may use a cabinet (s) of a higher rating safely (8 Ohm) with no
degradation in tone, however the amplifier will not produce its full rated wattage. Minimum load rating is 2 Ohms and while the MPULSE will handle this lower load condition - and in fact produce more than its rated power, it is not recommended. Prolonged use
of a 2 Ohm load will cause the power mosfets to run hot causing the protection circuit to trigger and mute the output signal until such
time as the mosfets can return to a safe operating temperature. Avoid using 2 Ohm loads whenever possible.
3. Use high quality cable from your instrument to the M-PULSE and from the M-PULSE to your speaker. Instrument cable
should be relatively low capacitance shielded cable. Whenever possible use lengths of 15 feet or shorter. Longer than 15’ tends to
introduce too much capacitance resulting in reduced punch and top end clarity. Speaker cable should be at least 14 gauge (or thicker)
unshielded cable and again try to keep the length of cable as short as possible for the best tonal results.
4. The BASS and TREBLE controls are active type controls with a broad response even though they are acting primarily on their
center frequency Q point. This broader response works extremely well with the passive, broad-band MID control. Because BASS
and TREBLE are active controls, they actually cut (or notch) the region around the Q point when the control is set below 12:00, and
boost these frequencies when the control is set above 12:00. The MID works like a normal passive control and boosts a broad band
of frequencies as it is increased.
5. When using the Parametric EQ keep in mind that cutting (notching) undesirable frequencies is often preferable to boosting
desirable ones. By using this technique you will keep noise to a minimum and ensure ample headroom at all times. The Parametric
is a powerful tone shaping tool when used tastefully, but all too often they are abused and set to their extremes which can result in
an unbalanced tone that is “full of holes” or excessive noise.
6. When using the EFFECTS LOOP to patch in your outboard processing, the best sonic results are usually found with the processors’ dry/wet mix set to 100% wet, and the M-PULSE EFFECTS MIX control set as close to 10% as possible. Following this scheme
preserves the integrity of the M-PULSEs’ tone by mixing in a very small amount of a very wet signal with a high ratio of the original
dry signal.
7. The Footcontroller must be connected and SOLO triggered for it to affect the signal.
8. The DIRECT OUTPUT circuit provides a GROUND LIFT that disconnects chassis ground from circuit ground. Should you encounter
a hum or buzz when interfacing to live or recording consoles, try flipping this ground lift after you have muted that channels’ input or
zero’ed the fader. Many times (but not all) the hum is created by a ground loop between the M-PULSE and the console and lifting
the M-PULSE chassis to circuit ground will remedy the situation.
9. Extreme settings of the Compressor will affect the overall output available, making the amplifier seem not quite as powerful. This is a
result of removing the dynamic content of the signal. May we suggest using the COMPRESSOR tastefully and at less than extreme settings to attain the best all around performance...unless a desired special effect requires that you disregard more “normal” settings.
Hopefully these hints have helped get you up and running with your new M-PULSE and you are well on your way to having the best
tone you have ever heard! Now that you have a better idea of the layout and features, we are ready to move on to understanding the
individual controls and circuits in more detail.
PAGE 3
FRONT PANEL:
ACTIVE / PASSIVE SWITCH:
FRONT PANEL CONTROLS:
GAIN:
ACTIVE
PASSIVE
INPUT
GAIN BASS MID TREBLE
FOUR - STAGE VACUUM TUBE PREAMPLIFIER
ON
POWER
ON
FS
OFF
0 db 0 0 0 0
40 Hz 120 400 1.4K 6K
SEMI - PARAMETRIC EQUALIZER
30 90 250 900 4K
SIMUL STATE POWER
THRESHOLD RATIO MAIN SOLO
COMPRESSION MASTER VOLUMES
ON
FS
OFF
ENGINEERING
S I M U L S T A T E B A S S A M P L I F I E R
TM
GAIN BASS
FOUR - STAGE VACUMM
This switch allows you to match the signal output level of virtually any instrument.
The ACTIVE position is padded down for greater input stage headroom and this works well with basses that use an on-board pre-
amp with an active tone control circuit. Usually these instruments put out a much hotter signal than conventional
basses, even when their tone controls are set “flat”. The added headroom is needed to prevent clipping in the
first stage of the pre-amp and the ACTIVE position should be used whenever instruments that utilize active style
pickup/EQ harnesses are used.
You can use the ACTIVE position for conventional passive instruments also, for heavy handed players needing
extra headroom or simply a “cleaner” sound. However, note that unless you have Kong size hands it may be
difficult to bring the amplifier to full power with this reduced front end sensitivity.
The PASSIVE position is set up for more conventional basses with passive pickups that produce lower output
signal levels. This position is more sensitive than ACTIVE and therefore can drive the first stage to clip with a
much lower signal. Keep this in mind if you play with a heavy touch or want a little bit of growl or front end clip. In those scenarios this
setting can be quite useful to push the first stage of the pre-amp.
This control determines the overall character of the input sensitivity. The lower regions of the control (below 12:00) lend
greater headroom and provide a scooped, brighter personality. The upper harmonics come through more prominently in this area of
the control making the top end sound more transparent and sweet. This region is especially useful for funkier stuff when thumbing is
in order. It keeps the rubber- band feel intact in the lows and mids while voicing the snap just high enough to avoid harshness, or the
dreaded “gak” when the G string is plucked.
As the GAIN control is increased past 12:00 a richer, more “well-rounded” voice becomes dominant and headroom starts to diminish
in increments until eventually, a tube overdrive sound appears as the 12AX7 input tube is driven into
saturation.
The region between 12:00 and 2:30 is where the classic, warm tube sound resides and within this narrow
band you will discover a world of tone. Tiny increments here produce subtle, but important differences in
the attack characteristic which in turn, feel like changes in the time domain. By experimenting with the
amount of gain, you can actually voice the amp to feel as if it bounces just ahead of the groove - or lays
back a little deeper to produce a more Fatback feel. The difference in attack and sustain produces striking
results as to how the bassist - and in fact the whole band - perceives things in the time domain.
PAGE 4
Loading...