Gallien-Krueger MB Fusion 800 operation manual

MB FUSION 800

OWNER’S MANUAL

MB FUSION 800

Congratulations!

Your purchase of a new Gallien-Krueger MB
Fusion 800 amplifier is surely the result of much
careful consideration
we at Gallien-Krueger are pleased that you chose
us, and are determined that you will be a satisfied
customer. In choosing a MB Fusion 800 amplifier,
you now own an amplifier with many unique
features which will allow you to create your own
distinct sound.

on your part. For our part,

To get the most out of your new purchase, please

Introduction

take a few minutes to read through this manual.
If you are in a hurry, we suggest you at least read
through the Quick Start section before setting up
your new rig. This will help get you started and
give you a few quick tips, but is
for reading the rest of the manual.

Your amplifier should have come with the
following items, please check the contents of the
box to ensure that you have everything.

Included with your MB Fusion 800 amp:

Power cord 1
Owner’s manual 1
Warranty card (U.S. only) 1
Safety instructions sheet 1
One button foot switch 1

If your MB Fusion 800 amplifier did not come with all
the items listed, or if you encounter problems
while setting up your new equipment, please
contact your local dealer or GK as soon as
possible.

Gallien-Krueger, Inc.

2234 Industrial Drive
Stockton, CA 95206
phone: [phone]
fax: [phone]
www.gallien.com
email: [e-mail]

We wish you a lifetime of good playing and
remember to always have fun

not a substitute

!

GK Philosophy

I have never seen the point in doing things
the way others have done them. I also have not
been very interested in following the latest fad.
I’m a Stanford educated engineer who worked
my way through school as a musician. Like all
musicians, I have lugged amplifiers up stairways
and into car trunks, always wondering why these
things had to be so heavy, bulky and hard to
handle.
As the principal innovator at GK, our
products reflect my attitudes and life
experiences. I don’t model my designs after
other manufacturers’ products. Instead, I
believe new and old problems are best solved with
new solutions. Having
products enjoy a unique, unmatched sound,
allowing you every opportunity to make an
original statement.
Having supported my products for over
forty years, I have learned from the story they tell.
Gallien-Krueger is a reflection of that story, and
has a commitment to support that legacy. Just as
the products I created over forty years ago are still
telling their story, the products we create today
will be talking to us tomorrow.

We’ll be listening,

Robert Gallien
Founder and President

taken our own path, GK

2

Table Of Contents

MB FUSION 800

Safety Information
Quick Start/Tech Talk
Front Panel Controls
Rear Panel Features
Specications

4
5
6
7
8

*All Features and specications are subject to change without notice

Please read the Safety Information section on page 4 before continuing.

Gallien-Krueger
2234 Industrial Drive
Stockton, CA 95206
phone: [phone]
fax: [phone]

email: [e-mail]
www.gallien.com

Warning!
This amplifier is capable of producing high
sound pressure levels. Continued exposure
to high SPL’s can cause damage to your
hearing. Always set the volume at a safe
listening level or use hearing the volume at a
safe

listening level or use hearing

Table of Contents

C AU TION :

The lightning f lash with arrow head
symbol, wit hin the equilateral
triangle, i s int ended to alert the
us er to t he presence of uninsulat ed
“dangerous volt age” within the
product enc losure that may be of
su ffi cient magnitude t o constit ut e a
risk o f electric shock to persons

WA RNING :

C AU TION :

ATTENTION:

TO R EDUCE T HE RISK OF FIRE OR EL ECT RI C S HOC K,
DO N OT EXPOSE T HIS APPLIANCE TO R AIN OR MOISTURE

TO PR EVENT E LEC TRI C SH OC K, MAT CH WIDE BLA DE OF PLUG TO
WIDE SL OT, FULLY I NSERTED .

POUR EVITER LES CHO CS ELE CT RIQUES, INRO DUIRE LA LAM ELA
PLUS LAR GE DE LA FICHE DAN S L A BORNE CO RRESPONDANTE
DE LA P RISE ET POU SER JU SQU’AU FOND.

C A U TION

DO N OT OPEN

RISK OF ELE CTR IC S HOC K

TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT
REMOVE TOP COVER. NO USER SERVICEABLE PARTS
INSIDE. REFER ALL SERVICING TO QUALIFIED
SERVICE PERSONNEL.

The e xclamation point wit hin an
equilateral t riangle, is intended t o
alert the u ser t o the presence of
important operating, serv icing and
maintenanc e instructions in t he
literat ure accompany ing this
appliance .

3

MB FUSION 800

Safety Information

Please read all enclosed safety precautions before
connecting or operating this product.

Verify Line Voltage and Amperage:

Your new amp has been factory configured for use
with the specific line voltage for your location.
Products using 100-120 volt power supplies are not
compatible in locations wired for 200-240 volt
operation and 200-240 volt units are not compatible
in 100-120 volt locations.

120 Volt/60Hz 15A circuit for
USA/Canada.
230 Volt/(50/60Hz) 10A circuit for

Safety Information

UK/Australia.
230 Volt/(50/60Hz) 10A circuit for
Europe.
100 Volt/50Hz 15A circuit for
Japan.
220 Volt/50Hz 10A circuit for
Korea.
Proper AC circuit for all other
countries.

Connecting the amplifier to a line with specifications
other than indicated above can create safety and fire
hazard, and may damage the amplifier. If you have any
questions about the voltage requirements for your
specific model, or about the line voltage in your area,
contact your dealer before plugging the unit into a wall
outlet.

Verify AC Circuit Capacity Before Use:

high power output of your amplifier may require heavy
current draw under full-load conditions. To insure
proper performance and avoid potential safety hazards,
we recommend connection to line circuits with
amperage specified above. Connecting to the same
circuit used by other heavy power devices, such as high
wattage lights, may cause circuit breakers to trip. It is
always a good idea to avoid using any audio equipment
on the same AC circuit as equipment with motors, such
as air conditioners or refrigerators. This will lessen the
possibility of power variation and electrical start-up
noise affecting your sound.

AC Power Cord:

the power cord supplied with your unit. If a
replacement cord is needed, make certain to use a
standard IEC compliant cord. Damaged power cords
should be replaced immediately. When setting up, make
certain that the AC plug is easily accessible. If you do
not intend to use the amplifier for a considerable length
of time, disconnect the plug from the AC Mains Socket.
Do not use an extension cord.

Earth Grounding Connection: To prevent electric

shock, do not remove the grounding plug on the power
cord, or use any plug or extension cord that

To avoid safety hazards, use only

The

does not have a grounding plug provided. Make certain
that the AC outlet is properly grounded as well. Do not
use an adapter plug with this product

Do Not Open the Amplifier Enclosure:

are no user serviceable parts inside this product.
Opening the amplifier enclosure may present a shock
hazard. Modification to the product will void your
warranty. If liquid enters the unit, or any metal object
such as a paper clip accidentally falls inside the
enclosure, disconnect the unit from the AC power
source immediately and consult an authorized service
station.

Setup:

To insure proper operation and to avoid

potential safety hazards, place the unit on a firm, level
surface. Do not plug or unplug the instrument or
speaker cable while the amplifier power is on.

Heat & Ventilation:

provided for proper ventilation. There should be at least
one centimeter (.4 inches) on top and nine centimeters
(3.54 inches) clearance along the sides and rear of unit
for proper ventilation. This also applies to rack
mounting the unit. GK recommends using the MB
Fusion 800 Rack Kit available from an authorized GK
dealer or from our store at www.gallien.com.

Avoid using in extremely hot or cold locations and
areas that are exposed to direct sunlight or near heating
equipment. Avoid using in moist or high humidity
areas.

Remember, power amplifiers generate heat. The
ventilation slots on the enclosure are specifically
designed to remove this heat. Blocking or placing other
electronic equipment near the heat dissipation system
may possibly affect the long term reliability of both
your amplifier and the other equipment.

NEVER BLOCK THE FANS OR VENT
HOLES ON THE SIDES OF THE UNIT!

Make sure there is space

.

There

4

MB FUSION 800

Quick Start

These directions will take you through the basics
and give you a good start for setting up your sound.

Connect your Speaker: Connect your speaker
cabinets to the amplifier outputs marked
SPEAKER using a standard two conductor
speakon cable or Gallien-Krueger four conductor
speaker cable. Be sure not to exceed the
recommended speaker load as noted below.

Maximum Recommended Speaker Loads: One 4
Ohm, and one or two 8 Ohm cabinets.

Initial front panel control settings: Set all EQ
controls and the contour knob to 12 o’clock. Set the
Gain A, Gain B, Level B and Master controls to the
full counter clockwise position. Disengage all
voicing filter functions by pressing the contour,
treble and bass knobs until they are lit white.
Confirm that the Gain A and Limiter are active by
pressing the Gain A and Master knob until they are
lit blue. The -10db and mute switch should be in the
off (down) position.

Plug in your bass: Using an instrument (shielded)
cable, connect your bass to the input jack and press
the power switch to the on (in) position. If you
have active tone controls on your bass, turn all of
the controls to the middle or flat position and turn
the volume all the way up. If you have
conventional, passive tone controls, turn all tone
and volume controls all the way up.

Level and Master Volume settings: Set the Master
control to 12 o’clock. Turn the Gain A knob up as
you play until the desired output volume is reached.
If distortion is audible due to input clipping, (or the
ring surrounding the pad switch frequently flashes
red) set the -10dB pad switch to up position and
increase the Gain A level until the desired output
volume is reached. Decrease the volume on your
instrument if clipping persists. For high volume
applications, it may be necessary to increase the
Master control beyond the 12 o’clock setting.

Gain B/Level B: Pushing the Gain B knob (also
selectable from the provided footswitch) activates
the Gain B input and Level B controls. Once
activated ( indicated by the Gain B and Level B
knob lit blue ), bring the Level B control to the 12
o’clock position and increase the Gain B level until
the desired volume is heard. Higher Gain B
settings will produce more overdriven/distorted
tones while lower settings will maintain a clearer,
less overdriven tone. When used in conjunction
with the Level B control, the desired overdrive and
output volume can be set relative to the Gain A level.
Y

ou should be hearing your bass quite well through
both the Gain A and Gain B channels. At this point
you can experiment with different EQ and Contour
settings.

Tech Talk

Deep: The Deep switch extends the low frequency

range of the amplifier to accommodate the extra low
range of the B string on 5 and 6 string basses. Players
of four string basses may also find desirable results
with this filter as well.

Presence: The Presence control adds extra sparkle
on the high end for better clarity and ‘openness’ in
your tone. This is particularly useful when soloing or
playing chords.

Limiter: When the limiter is engaged it prevents the
power amp from distorting.

The Limiter is active
upon power up (Master is lit blue) and is
recommended for high volume applications.

Active Equalization: The equalizer in GK
amplifiers is unique and reflects over 40 years of
continuous development and refinement. The active
circuitry allows you to either boost or cut at a given
frequency with greater integrity in signal
reproduction. The treble is a shelving type control
that boosts the high frequencies evenly.
Respectively, the bass is a shelving control that
evenly boosts the low frequencies. The high mid and
low mid are peak (band pass) type controls with wide
Q (bandwidth) patterns which are much more
musical sounding.

Contour: The Contour adds a variable control and
center frequency select for precise tone shaping.
With the control at zero, the response is essentially
‘flat’ (as in no shaping). As the contour is increased,
it scoops out the midrange. Additionally, it
compensates to keep the overall volume level
constant. With it’s variable control, the Contour will
accommodate everyone from the smooth finger style
player to the aggressive slap player.

Gain and Master A/B: The Gain A/B settings
determine the overall drive of the signal. Lower
settings will allow for the cleanest sound, while
higher settings will result in an overdriven signal as
the tubes distort. For high volume applications where
maximum headroom is desired, the Master A/B
knobs should be set a 3 o’clock or higher.

Direct Out: The MB Fusion provides a low noise,
high quality balanced direct output for connection to
PA and recording consoles. With the Pre/Post EQ
switch set to “Pre” (Out), the direct output signal is
fed directly from the input stage. The direct output
signal is only effected by the Input Volume, -10db
Pad and Mute. This allows you to adjust your tone
and volume on stage without changing the Direct
Output signal. Changing the Pre/Post EQ switch to
“Post” (In), sends the "GK Sound" (EQ settings etc.)
and preamp response to the Direct out jack. This
gives you complete control over the Direct out’s tone
and volume.

Quick Start/Tech Talk

5

MB FUSION 800

INPUT

GAIN A CONTOUR TREBLE HI-MID LOW-MID BASS MASTERLEVEL-B

PUSH A

4

GAIN B

PUSH B PUSH

5 6

-10dB MUTE

CLIP

2

1

3

Front Panel Features

1

Input: A standard ¼” input jack to connect active or
passive basses using a shielded cable.

-10 dB Pad/Clip indicator: This is generally set to

2

the down position except in cases where distortion is
audible due to input clipping or if the ring around the

Front Panel Controls

switch flashes red often. If the -10dB pad is active
(up position) and input clipping is still audible,
reduce the volume on your bass.

3

Mute: Set this switch to on (up) position when
tuning or unplugging your instrument. The input
signal will be sent to the tuner output located on the
rear panel but no signal will be sent to the speaker or
XLR outputs. When the mute is active, the ring
surrounding the mute switch will be lit red.

4

Gain A (push): Sets the preamp gain after the input
stage and is used in conjunction with the input pad to
optimize the input signal level sent through the
preamp. Activated by default upon power up and
when the Gain A knob is pressed as well as from the
provided footswitch. The Gain A knob is lit blue
when active.

5

Gain B (push): Allows an additional preamp gain
level to be set independent of Gain A. When used in
conjunction with the Level B control, the desired
overdrive and output volume can be set relative to the
Gain A level. Activated by pressing the Gain B knob
or by the included footswitch. Gain B remains active
and is lit blue until Gain A is selected.

6

Contour: With the control at zero (full counter
clockwise position), the response is considered “flat”
(no tone shaping). As the Contour knob is turned
clockwise mid frequencies are reduced and low and
high frequencies are increased while maintaining
uniform volume.

Push Contour: Pushing the Contour knob toggles
the center frequency of the Contour circuit
between 500Hz (knob lit white) and 800Hz
(knob lit blue).

7

Treble (push): (+10/-19dB @7 kHz) Boost and cut
shelving EQ. Use this control to add or remove edge
and definition.

Push Presence: (+4dB@10kHz) Adds extra sparkle
on the high end for better clarity and openness in
your tone. This is particularly useful when soloing or
playing chords. Pushing the Treble knob toggles the
Presence circuit off (knob lit white) and on (knob lit
blue).

WHT 500 Hz

BLU 800 Hz

PUSH

PRESENCE

7

POWER

OFF

ON

11

PUSH LIM

MB FUSION

12

800

13

PUSH
DEEP

8

8

Hi-Mid: (+5/-8dB @ 1kHz) Boost and cut “Q

10

9

Optimized” band pass EQ. This works on lower
string harmonics and effects the punch of your
sound.

9

Lo-Mid: (+6/-9dB @ 250Hz) Boost and cut ”Q
optimized” band pass EQ. This works for the main
body of your sound.

10

Bass (push): (+/-14dB @ 40Hz) Boost and cut
shelving EQ. This is used to control the low end push
of your sound.

Push Deep: (+4dB @ 30Hz) Extends the low
frequency range of the amplifier to accommodate the
extra low range of the B string on a 5 or 6 string bass.
Users of 4 string basses may also find desirable
results with this filter as well. Pushing the Bass knob
toggles the Deep circuit off (knob lit white) and on
(knob lit blue).

11

Level B: This is the volume control prior to the
Master when Gain B is activated. When used in
conjunction with the Gain B knob, varying amounts
of tube overdrive and/or volume boost are available.
Level B is lit blue when active.

Master (push): This is the final master volume when

12

Gain A or Gain B/Level B are activated. This sets the
overall output of the amplifier once the appropriate
volume ratio between the Gain A and Gain B are set.
Push Limiter: Prevents the power amp from
distorting and is recommended during high volume
applications. Upon powering up the amplifier, the
Master knob indicator is lit blue indicating the limiter
is engaged. When the Master knob is pushed the
limiter function is disengaged and the knob indicator
changes to white. If power amp clipping occurs, the
knob indicator will flash red indicating that the
limiter function should be engaged.

13

Power Switch: Turns the amplifier on and off. When

pushed to the in (on) position, the ring surrounding
the button will light red during power up then change
to blue, indicating the amp is ready for normal
operation. Should the amp experience a fault
(overheat or over current) the amp will mute and the
ring will light red until the condition is corrected.
This LED turns off when the power is switched to the
out (off) position. This turns the amp off but it does
not completely disconnect the power from the AC
mains.

6

Gain A/B Sample Setting

PUSH

WHT 500 Hz

BLU 800 Hz

PUSH
DEEP

PUSH

PRESENCE

MB FUSION 800

INPUT

GAIN A CONTOUR TREBLE HI-MID LOW-MID BASS MASTERLEVEL-B

PUSH A

GAIN B

PUSH B

-10dB MUTE

CLIP

The switchable Gain A and Gain B settings can
be used to achieve a volume boost or volume cut
as well as to add “GK growl” when selected by
the footswitch or by pressing the corresponding
knob on the front panel. The illustration above
shows one possible setting for clean, high

DIRECT OUT

EQ

PRE

AC INPUT

120V/60Hz

1

POST

2

4

3

Rear Panel Features

1

AC Receptacle: The detachable power cord
plugs in here.

2

Balanced Direct Out: This electronically
balanced output allows a direct connection to a
P.A. system.

3

Pre/Post EQ Button: This button switches the
direct out signal to be before or after the EQ.

4

Foot switch Input: A foot switch is provided to
toggle between Gain A and Gain B modes.

5

Tuner Output: This output comes directly off of
the input stage and can be patched to a tuner
using a shielded patch cord. This output is
unaffected by the Tuning Mute Feature.

6

Return: This input allows the signal from
outboard effects devices to be inserted before the
boost section.

7

Send: This output allows signal from the preamp
to be fed to outboard effects devices from a point
after the EQ section.

8

Headphone/Line out/Chain out: This unique
output allows the user to send a direct

PUSH LIM

MB FUSION

headroom when Gain A is active and a more
overdriven tone when Gain B is activated. Level

B is used to determine the relative volume while
Gain B is selected. The Master sets the overall
output while either Gain A or Gain B are active.

PATCH BAY

6

5

SENDRETURNTUNERFT. SWITCH

FX

HEADPHONES (1)

LINE OUT/CHAIN OUT (2)

7

1

2

8

9

(unbalanced) line out to devices with unbalanced
inputs such as personal multitrack recorders. This
connection requires a shielded patch cord. The
Chain out allows the user to connect directly to a
GK MBP powered extension cabinet. This
connection is made with a balanced, tip, ring,
sleeve to male XLR cable.

tip ring sleeve

Unswitched, this headphone jack can be used to
monitor your playing with headphones.

9

Headphone/Line Out/Chain Out switch: This
button toggles the output from headphone to
line/chain out.

10

Speaker: The speaker output to a speaker cabinet
delivers 800w into 4 Ohm loads. Lower
impedances such as 8 Ohms or 16 Ohms and no
load are acceptable. One 4 Ohm speaker and one
8 Ohm speaker is not recommended. A high
current twist-lock 2 pin or 4 pin GK Speakon
connector is required for this connection.

POWER

OFF

ON

800

800 WATTS @ 4 OHMS

SPEAKER

CLASS 2 WIRING

10

Rear Panel Features

male

XLR

7

CONTOUR BRIGHT

R

INPUT

-10dB

Introduction

500HZ

800HZ

MB FUSION 800

MB FUSION 800 BLOCK DIAGRAM

PRE

DEEP

POST

HI-MID

GAIN A

A-B/ FOOT

SW

GAIN B

LOW MID BASS

TUNER

SEND

MASTER A

TREBLE

MASTER B

SPECIFICATIONS

RETURN

A-B/ FOOT

SW

MUTE

GRND LIFT

DETECTOR

LIMITER

CLIP

BALANCE

DIRECT OUT

ONOFF

800W/ 4 OHMS

DIGITAL POWER AMP

HEAD PHONE

LINE OUT/CHAIN OUT

SWITCH

LINE OUT/CHAIN OUT

1+

1- 2-

2+

1+

1- 2-

2+

RING
TIP

SPEAKON JACK

SPEAKON JACK

HEAD PHONE/
LINE OUT

Power Output: 560W @ 8 Ohms
800W @ 4 Ohms
Audio Inputs:
Instrument Input 1/4" Mono, Unbalanced
Level 0.6 Vrms
w/ -10dB 1.6 Vrms
Impedance 1 M Ohm
Return Input 1/4" Mono, Unbalanced
Impedance 50k Ohms

Audio Outputs:
Send Output 1/4" Mono, Unbalanced
Impedance 220 Ohms
Tuner Output 1/4" Mono, Unbalanced
Impedance 10K Ohms
Direct Out XLR, Balanced
Impedance 500 Ohms

Speaker Out Speakon Jack, x2

Equalizer:

Bass +/-14dB @ 40Hz
Lo-Mid +6/-9dB @ 250Hz
Hi-Mid +5/-8dB @ 1kHz
Treble +10/-19dB @ 7kHz

Voicing Filters:

Contour -16dB @ 500Hz or

-15dB @ 800Hz
Deep +4dB @ 30Hz
Bright +4dB @ 10kHz

Noise: -90dB "A" weighted
Cooling: Variable Speed Fan

MB FUSION 800 BASS AMPLIFIER

OWNER'S MANUAL
PART # 160-0710-A

Protection: Full short circuit, thermal, RF
protection Stable into reactive and
mismatched loads. Five second
muted warm up
Dimensions: 1.75" [44.45mm] High

11.00" [279.40mm] Wide

12.25" [311.15mm] Deep
1 Rack space

Weight: 5.5lbs.
Consumption: 880W (Full)

160W (Average)
Mains Voltage: USA/CANADA 120 Volts, 60Hz
UK/Australia 240 Volts, 50Hz
Europe 230/240 Volts, 50/60Hz
Japan 100 Volts, 50/60Hz
Korea 220 Volts, 50 Hz
Mains: Standard IEC Receptacle.

LR110409

This device has been tested and found to
comply with CAN/CSA 60065-03 Safety
Requirements.

USC

UL std. No. 60065-2007 Safety
Requirements.

This device complies with Part 15 of the
FCC Rules. Operation is subject to the
following two conditions:
(1) This device may not cause harmful
interference, and
(2) This device must accept any
interference received, including
interference that may cause undesired
operation.
Note: This equipment has been tested and
found to comply with the limits for a
Class B digital device, pursuant to part 15
of the FCC Rules.

8