Gallien-krueger MB500 User Manual

MB500

MB500

OWNER’S MANUAL

OWNER’S MANUAL

MB500

MB500

Congratulations!

Your purchase of a new Gallien-Krueger MB
Series amplifier is surely the result of much care­ful consideration
at Gallien-Krueger are pleased that you chose us,
and are determined that you will be a satisfied
customer. In choosing a MB Series 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, we

To get the most out of your new purchase, please
take a few minutes to read through this manual.

Introduction

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 not a substitute
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 500 Amplifier:

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

*Item purchased outside the U.S. are supported by
the distributor. Contact the distributor in your
country for warranty coverage.

If your MB Series amplifier did not come with all
items listed, or if you encounter problems wh
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]
Internet: www.gallien-krueger.com
Email: [e-mail]

the

ile

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 taken our own path, GK
products enjoy a unique, unmatched sound,
allowing you every opportunity to make an
original statement.

Having supported my products for over thirty
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 thirty five years ago
are still telling their story, the products we create
today will be talking to us tomorrow.

We’ll be listening,

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

Robert Gallien
Founder and President

2

MB500

MB500

Table Of Contents

Safety Information 4
Quick Start 5
Front Panel Controls 6
Rear Panel Features 7
Sample Settings 8
Sound Tips 9
Installation and Maintenance 10
Tech Talk 11
Specifications 12

*All Features and specifications are subject to change without notice

Please read the Safety Information section on page 4 and installation
instructions on page 10 before continuing.

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

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

Table of Contents

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 protection if the unit

is operated at higher levels.

CAUTION

RISK OF ELECTRIC SHOCK

CAUTION:

The lightning flash with arrow

presence of uninsulated “dangerous voltage”
within the product inclosure that may be of
sufficient magnitude to constitute
a risk of electitric shock to persons

WARNING:

CAUTION:

ATTENTION:

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

head symbol, within the
equilateral triangle, is
intended to alert the user to the

TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK,
DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE

TO PREVENT ELECTRIC SHOCK, MATCH WIDE BLADE OF PLUG TO
WIDE SLOT, FULLY INSERTED.

POUR EVITER LES CHOCS ELECTRIQUES, INRODUIRE LA LAME LA
PLUS LARGE DE LA FICHE DANS LA BORNE CORRESPONDANTE
DE LA PRISE ET POUSER JUSQU’AU FOND.

DO NOT OPEN

The exclamation point within an

to alert the user to the presence

maintenance (
literature accompanying the appliance.

equilateral triangle, is intended

of important operating and

!

servicing) instructions in the

!

3

MB500

MB500

Safety Information

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

Verify Line Voltage and Amperage: Your new
MB 500 Bass amplifier has been factory
configured for use with the specific line voltage
for your location:

100-120 Volts/60Hz 15A circuit for USA/Canada.
220-240 Volts/(50-60Hz) 10A circuit for
UK/Australia.
220-240 Volts/(50-60Hz) 10A circuit for Europe.
100-120 Volts/50Hz 15A circuit for Japan.
220-240 Volts/50Hz 10A circuit for Korea.
Proper AC circuit for all other countries.

Safety Information

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:

The 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
“as 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 sameAC 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.

Please refer to page 10 for more
instructions concerning installation.

AC Power Cord:

To avoid safety hazards, use only 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 extention 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 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 theAC 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:

Make sure there is space provided for proper
ventilation. Avoidusing 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.

THE FAN VENT HOLES ON THE SIDES
OF THE UNIT.

NEVER BLOCK

There

4

MB500

MB500

Quick Start

The MB 500 amplifier is designed to be simple to operate. All controls have a well defined purpose.
These directions will take you through the basics and give you a good start for setting up your sound.

1. Plug it in:

Set the power switch to Off and connect the supplied power cord, from the amplifier AC receptacle, to
an AC power outlet of proper voltage and power rating (see safety information on page 5 for details).

2. Connect your cabinets:

Connect your speaker cabinets to the amplifier outputs marked Speaker. The MB features dual use
speaker connections. These unique jacks allow for Speakon or 1/4” plugs to be used. Be sure not to
exceed the recommended speaker load as noted below.

Maximum Recommended Speaker Loads:

One 4 Ohm, or two 8 Ohm cabinets.

3. Initial front panel control settings:

Set all EQ controls and contour knob to 12 o’clock. Set the Input Volume, Master and Master B
controls at 0. The Boost knob should be set to 12 o' clock and the boost button (between Boost and
Master B konbs) in the out position.

4. Plug in your bass:

Using an instrument (shielded) cable, connect your bass to the Input jack and press the power switch
on. 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.

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5. Level and Master Volume Settings:

Set the Master Volume to 3 o’clock. Turn the Input Volume knob up as you play to the desired output
level. It is recommended that the limiter be used during high volume applications. If the clip light (pad
button) flashes more than occasionally, press the -10dB pad button in and turn the Input Volume knob
up. If it is still lighting often, try turning the volume down on your bass.

6. Boost/Master B:

Engage the button located between the Boost and Master B knobs. This will activate the Boost section
of the pre amp. This can also be done with the included foot switch. Turn up the Master B knob to the
desired volume level.

You should be hearing your bass quite well through the Master and Master B channels. At this point
you can experiment with different EQ, Contour and Boost settings. Various sample settings can also be
found on page 8.

5

MB500

MB500

ON

OFFONOFF

ON

OFF

15

Front Panel Features

INPUT

-10dB

OFF

ON

CLIP

1

2

GAIN CONTOUR TREBLE HI-MID LOW-MID BASS BOOST MASTER-B M A STER

MUTE

4

3

5 6

Front Panel Features

1

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

2

-10 dB Pad/Clip indicator: Input attenuator
button. This button is generally set to the out
position except in cases where the clip LED
flashes more than occasionally. It may be
necessary to “pad” the input if you are using a
bass with active electronics or very high output.
The pad button light flashes red when the input is
being overdriven. If the -10dB is pressed and the
clip indicator still flashes frequently, reduce the
volume on your bass.

3

Mute: Set this switch to “on” when tuning or
unplugging your bass. No signal will be sent to
the speakers or the P.A. system. When muted this
button turns red.

4

Gain: Sets the preamp gain after the input stage.
It is used in conjunction with the input pad to
optimize the amplifier’s headroom.

5

Contour: As part of the amps active equalization
the contour control decreases the mid-range
frequencies while boosting low and high
frequencies.

6

Treble: Boost and cut at 7 kHz +14 dB shelving
type. Use this control to add or remove edge and
definition.

7

Hi-Mid: Boost and cut at 1 kHz +6 dB. A “Q
Optimized,” band pass type, this works on lower
string harmonics and effects the punch of your
sound.

8

Low-Mid: Boost and cut at 250Hz +6dB/-10 dB.
A “Q optimized” band pass type, this works for
main body of your sound.

POWER

G.I.V.E

7

8

9

9

Bass: Boost and cut a 60Hz +10 dB, shelving

10

11

12

MB 500

13 14

type. This is used to control the low end push.
Boost: This is a post E.Q. gain stage using

10

G.I.V.E. technology which adds “growl” as it is
turned up.

11

GIVE: This button activates the Boost and
Master B volume control.. This can also be
activated using the foot switch (included).

12

Master B: This is the master volume control
when boost is activated.

13

Master: This is the master volume control when
the boost is inactive.

14

Power Switch: Turns the amplifier on and off. In
the on position, the ring surrounding the button
will light red during power up then changes to
blue, indicating the amp is ready for normal
operation. Should the amp experience a fault
(over heat 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 off. This turns the amp off but it does
not completely disconnect the power from the
AC mains.

15

Limiter: When this button is engaged it prevents
the power amp from distorting. It is
recommended that this feature be used during
high volume applications.

6

MB500

MB500

Safety Information

FULL POWER

580W

AC INPUT

120V/60Hz

GND

LIFT

2

DIRECT OUT

EQGND

PRE

POST

3 4 5 6 7 8 91 10

Rear Panel Features

1

AC Receptacle: The detachable power cord
plugs in here.

2

Ground Lift: This switch disconnects the
ground of the balanced, XLR output to eliminate
hum and buzz when connecting to equipment

Safety Information

that is running on a different ground system.

3

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

4

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

5

Foot switch Input: A foot switch is provided to
engage Boost and Master B modes.

6

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.

7

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

8

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

9

Headphone/Line out: When switched, this
output allows the user to send a direct
(unbalanced) line out to devices with unbalanced
inputs such as personal multitrack recorders.
This connection requires a shielded patch cord.
Unswitched, this headphone jack can be used to
monitor your playing with headphones.

PATCH BAY

SENDRETURNTUNERFT. SWITCH

HEADPHONES (1)

LINE OUT (2)

1

2

500 WATTS @ 4 OHMS

SPEAKER

CLASS 2 WIRING

11

FX

Headphone/Line out switch: This switch

10

toggles the output from headphone to line out.

11

Speaker: Power amp output to speaker cabinet.
Delivers 500w 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. This unique
speaker output allows you to use a ¼” plug or the
high current, twist-lock Speakon connector.

Rear Panel Features

7

MB500

MB500

ON

OFFONOFF

ON

OFF

ON

OFF

ON

OFFONOFF

ON

OFF

ON

OFF

ON

OFFONOFF

ON

OFF

ON

OFF

ON

OFFONOFF

ON

OFF

Settings & Sounds :

The MB 500 is versatile in its sound and tone. Below are a few suggested amp settings that can be
used as starting points to define your own sound.

*Volume settings should be adjusted to appropriate level.

It is recommended that the limiter be

used during high volume applications.

Note: At higher playing levels the contour should be set lower for mid-range clarity. To get
800RB voicing, the contour should be set to 0 or 10 only.

INPUT

Sample Settings

INPUT

Slap:

-10dB

OFF

ON

CLIP

GAIN CONTOUR TREBLE HI-MID LOW-MID BASS BOOST MASTE R-B M ASTER

MUTE

Rock:

-10dB

CLIP

GAIN CONTOUR TREBLE HI-MID LOW-MID BASS BOOST MASTE R-B M ASTER

MUTE

Reggae:

Both pickups recommended.

POWER

G.I.V.E

MB 500

Both pickups recommended.

POWER

G.I.V.E

MB 500

Front pickup recommended.

INPUT

-10dB

CLIP

INPUT

-10dB

CLIP

GAIN CONTOUR TREBLE HI-MID LOW-MID BASS BOOST MASTE R-B M ASTER

MUTE

G.I.V.E

Jazz/Fusion:

GAIN CONTOUR TREBLE HI-MID LOW-MID BASS BOOST MASTE R-B M ASTER

MUTE

G.I.V.E

Both pickups recommended.

POWER

MB 500

POWER

MB 500

8

M

B500

Sound Tips

M

B500

The MB 500 has several unique features which, if
used properly, will obtain the sound you have been
searching for.

The Equalizer:

The Equalizer is used to fine tune your sound.
When adjusting making adjustments, do it just a
little at a time. These are active circuits and small
changes can make a big difference in your sound.
With a little experimentation you will find that this
equalizer is very easy to use and provides you with
a large variety of great sounds unique to GK.

Contour:

Increasing the Contour level will scoop out
midrange frequencies while boosting the highs and
lows. The sound, once again, is unique to GK and
available on any other Bass amp. Lower contour
settings are recommended for midrange clarity at
higher playing levels.

Boost/Master B:

Turning up the Boost control will add a little growl
to your tone by adding a small amount of ever
order harmonic distortion. This is an unmistakable
GK trade mark sound that you will surely grow to
appreciate. Raising the Boost while lowering
Master B will add more growl while keeping the
sound level the same. You can use Master B to
increase or lower the overall output volume when
switching the Boost on via the front panel or from
the included foot switch. In either normal or boost
mode, the cleanest sound is obtained with Master
Volume settings at 3 o'clock.

Direct Out:

The MB Series provides a low noise, high quality
balanced direct output for connection to PA and
recording consoles. A Ground Lift switch is

included to remove hum and buzz when
connecting to equipment powered by a different
ground system.

With the Pre/Post EQ switch set to “Pre” (Out), the
direct output signal is fed directly from the input
stage providing a low noise output superior to
external direct boxes and impedance transformers.
In the "Pre" position, 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 level and confusing your sound man.

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.

Limiter: When this button is engaged it prevents
the power amp from distorting. It is recommended
that this feature b e used during high volume
applications.

Sound Tips

9

M

M

B500

B500

Installation:

To insure proper operation and to avoid potential
safety hazards, place the unit on a firm, level
surface.

Ventilation:

Make certain that proper space is provided for ven­tilation. Never block the fan vent holes located on
the sides of the amplifier. If the amplifier will be
installed in a rack or other enclosed area, make sure
that there is sufficient air movement within the
enclosure to allow proper cooling. Consult your
dealer for more information. Avoid installation in

Installation

extremely hot or cold locations, and areas that are
exposed to direct sunlight, or near heating equip­ment. Avoid moist or humid locations.

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 heat­dissipation system may possibly affect the long­term reliability of both your amplifier and the other
equipment.

Maintenance:

Your new amplifier is rugged. It was built to give
you a lifetime of trouble-free operation, if it is
operated in accordance with the instructions con­tained in this manual. The only maintenance
required is cleaning. If you are going to move your
amplifier around frequently, we recommend a road
case to protect it from scratches and road wear.

Packaging:

The carton and packing materials used in shipping
your new amplifier were specifically designed to cush­ion it from the shocks and vibration that occur during
transport. We suggest that you save the carton and
packing materials for use in shipping, in the event you
move, or the amplifier needs repair.

Moving the Unit:

Before moving the unit, be certain to disconnect
any interconnection cords with other components,
and make sure that you disconnect the unit from the
AC outlet.

Cleaning:

When the unit gets dirty, clean only with a dry
cloth. Never use benzene, thinner, alcohol, or other
volatile cleaning agents. Do not use abrasive clean­ers, as they may damage the finish of metal parts.
Avoid spraying insecticides near the unit.

10

MB500

MB500

Tech Talk

Characteristics of the MB 500:

The MB 500 is a flexible, state-of-the-art amplifier
designed to deliver maximum performance while
remaining small, lightweight and simple to operate.
This is accomplished through a few, very important
features:

· Class D power supply and power amp.

· Four, Bass specific bands of active equalization
for precise tone control.

.

“G.I.V.E.” Technology:

As in all GK pre-amps, the MB Series pre-amp
incorporates what we call G.I.V.E (Gate Induced
Valve Effect) Technology. We use field effect
devices with the gate biased in a way that
emphasizes the optimum harmonic content of the
signal. Working in concert with our unique Four
Band Active Equalizer, and three stage Voicing Filter
Section, G.I.V.E. technology produces a consistently
pleasing bass tone.

Tech Talk

· Balanced direct output eliminates the need for a
direct box.

· Continuously variable fan cooling.

Equalization:

Standard tone controls and graphic equalizers give
you plenty of variation, but they don’t provide what
the instrument really needs. The fact is, graphic
equalizers are intended for room equalization. The
equalization in Gallien-Krueger amplifiers reflects
40 years of continuous development and refinement.

The GK equalizer is unique to the industry, it’s not
just a normal four band equalizer, each section is a
special circuit optimized to perform a Bass specific
job in its range of operation.

These sections are wired in series, so they add to one
another creating a tremendously flexible equalizer,
that sounds natural at any setting. Now it is possible
to obtain the sound you desire.

Contour:

The Contour is used to completely revoice the
amplifier. The Contour control tunes between two
different shaping circuits, with greatly different
responses. With the control all the way up, the low
end is slightly boosted, the mids are dropped and the
high end is pushed up. This is only found in GK
amplifiers.

Limiter:

The limiter is designed to detect signal levels at the
input of the power amp that cause unwanted distor­tion. It attenuates extreme peaks to allow high
volume output while maintaining signal integrity.

Cool Running = Reliability:

To cool the amp when its being driven hard, we’ve
designed a temperature sensitive fan cooling system.
When the amp is under a light load, the fan is off or
running at a low speed, reducing fan noise. As the
amp works harder, the fan speed increases to keep
everything cool.

Smart Protection Circuitry:

The MB Series protection circuitry constantly
monitors for unsafe operating conditions such as
short circuits, miss-wired speaker cables, blown
speakers, improper ventilation, and incorrect speaker
configurations. In addition, protection is provided
during power up/down. If the MB Series senses any
unsafe operating conditions, the output signal is
immediately muted and the power light changes
from Blue to Red. The amplifier will remain muted
until the fault is removed. If the protection circuit
activates while playing, turn the amplifier off and
check the amplifier speaker output connections. Be
sure that you are not exceeding the maximum
recommend load described in this manual. If the
problem persists, contact GK directly for technical
advice.

In Closing:

You should now have a thorough understanding of
how your new MB Series amplifier works and what
advantages it can offer you in getting “your” sound.
We thank you for reading the Owner’s Manual and
wish you the best of times! Please send us your
comments via www.gallien-krueger.com or email us
at [e-mail].

11

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ci

f

icepS

1+

2+

2-

1+

2+

2-

MB500 BLOCK DIAGRAM

INPUT

GND

LIFT

CLIP

-10dB
PAD

DIRECT OUT

TUNING

MUTE

TUNER

PRE

POST

CONTOURGAIN

4 BAND

EQ

SEND

RETURN

BOOST

MASTER-B

G.I.V.E SW / FT SW

CLIP

DETECTOR

ONOFF

LIMITER

MASTER

500W/ 4 OHMS

DIGITAL POWER AMP

HEAD PHONE

LINE OUT

SW

LNE OUT

1+

1-1-2-

2+

1+

1-1-2-

2+

RING
TIP

HEAD PHONE/
LINE OUT

1/4” / SPEAKON

COMBO

1/4” / SPEAKON

COMBO

Specifications

s

Output Power:

Input Section:
Maximum Input Level
With -10dB pad
Input Impedance
Send Output Impedance
Return Input Impedance
Tuner Output Impedance
Direct Output Impedance

Equalizer:

Bass
Lo-Mid
Hi-Mid
Treble

Voicing Filters:

Contour

MB500 SPECS

350W @ 8 Ohms
500W @ 4 Ohms

0.6V Rms

1.6V Rms
1M Ohms
220 Ohms
50K Ohms
10K Ohms
500 Ohms

+/-10dB @ 60Hz
+6dB/-10dB @ 250Hz
+6dB/-10dB @ 1KHz
+/-14dB @ 7KHz

+2dB @ 50Hz/

-10dB @ 500Hz/
+3dB @ 7 KHz

Noise: -90 dB reference to 500W/350W, “A” Weighted

Cooling: Variable Speed Fan

Amplifier Protection:

Full short circuit, thermal and RF protection.
Stable into reactive and mismatch loads.
Five second muted warm-up.

Dimensions (HxWxD):

1.75”[44.45mm] x 11”[279.4mm] x 9”[228.67mm].
1 Rack spaces.

Weight:

3 lbs. 12 oz. 1.7 Kg.

Power requirements:

U.S.A./Canada 120V/60Hz.
580W(full power), 75.6W(average power)
Europe 230V/50Hz/60Hz
580W(full power), 75.6W(average power)
Japan 100V/50Hz
580W(full power), 75.6(average power)

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