Gallien-krueger 700RB User Manual

700RB

700RB Series

Owners Manual

700RB/210

700RB/112

700RB/115

700RB Series

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Table Of Contents

Table of Contents

Introduction.....................................................................

Quick Start.......................................................................

Sound Tips.......................................................................

Bi-Amp and Normal Operation....................................

Safety Information..........................................................

Installation and Maintenance........................................

Front Panel Controls.....................................................

Rear Panel Controls......................................................

700RB Series Combos...................................................

Tech Talk.......................................................................

Specifications.................................................................

*All Features and specifications are subject to change without notice

**This list is subject to change without notice.

3
5
6
7

8
9
10
11
12
13
16

.

CACAUTION:

COCOVER (OR BA

WARNING:

ATTENTION:

CORRESPOND

Gallien-Krueger

2240 Paragon Dr.
San Jose, CA, 95131
phone: [phone]
fax: [phone]
www.gallien-krueger.com

TO REDUCE

REFER SER

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within the product's enclosure that ma
sufficient magnitude to constitute a r
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TO REDUCE

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Congratulations

700RB Series

Your purchase of a new Gallien-Krueger 700RB Series
product is surely the result of much careful consideration
on your part. For our part, we at Gallien-Krueger are
pleased that you chose us, and are determined that you
will be a satisfied customer. In choosing a 700RB Series
product, you own an amplifier with many unique
features, that can take you where you have never been
before.

To get the most out of your new purchase please 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
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 700RB Head:
700RB 1
Rack mount Ears with Hardware 2
RBH Amplifier Clip 2
Power Cord 1
4 Conductor Speakon Cable 1
Owner’s Manual 1
Warranty Card 1
Safety Instructions Sheet 1

If your 700RB Series amplifier or combo did not come
with all the items listed above, or if you encounter
problems while setting up your new equipment, please
contact your local dealer, or us as soon as possible at:

Gallien-Kruger, Inc.
2240 Paragon Drive
San Jose, CA 95131
phone: [phone]
fax: [phone]
Internet: www.gallien-krueger.com
Email: [e-mail]

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

Introduction

Included with your 700RB Combo:
700RB/112 (/115, or /210) 1
Power Cord 1
Owner’s Manual 1
Warranty Card 1
Safety Instructions Sheet 1

3

Always Listening

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 am a Stanford
educated engineer who worked his 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.

Introduction

As I am the principal innovator at
reflect my attitudes and life experiences. I don’t model
my designs after other manufacturer’s products (as
some of our competitors are proud of reciting).
Instead, I believe new and old problems are best solved
with new solutions. Having taken our own path,
products enjoy a unique, unmatched sound, allowing
the artist using them every opportunity to make an
original statement.
Having supported my products for over thirty years, I
have learned from the story they tell.
is a reflection of that story, and has a commitment to
support that legacy. Just as the products I created
thirty years ago are still telling their story, the products
we create today will be talking to us tomorrow.
We’ll be listening,

GK

, our products

Gallien-Krueger

700RB Series

GK

Robert Gallien

4

Quick Start

The 700RB Series is designed to be simple to operate.
All controls have a well defined purpose and are well
behaved. These directions will take you through the
basics and give you a good start for setting up your
sound.

700RB Series

Quick Start

First:

Set the power switch to Off and connect the supplied
power cable, from the amplifier AC receptacle, to an AC
power outlet of proper voltage and power rating (see
safety information on page 7 for details).

Next:

Connect your speaker cabinets to the amplifier outputs
marked 380W AMP ONLY or “SPEAKON” OUTPUTS.
Be sure not to exceed the recommended speaker load
below.

Maximum Recommended Speaker Load:

One 4 Ohm, or two 8 Ohm cabinets on the 380W Amp.
One or two 8 Ohm horns on the 50W Amp.

If you are using an RBH Series cabinet, use the supplied
4 conductor Speakon cable to connect to the “Speakon”
outputs on the rear panel of the amplifier. Set the Woofer
X-Over and Tweeter Hi Cut switches on the front panel to
the IN position. In addition, set the switch on the RBH
cabinet to Bi-Amp.

For connection to all other cabinets, connect to the 1/4”
outputs labeled 380W amp only. Set the Woofer X­Over switch on the front panel to the Out position.

For more information on Bi-Amp and Normal Operation,
see page 7.

Caution:

Do not connect the Speakon cable labeled “Bridge Mode”
to the 700RB. This may result in damage to the ampli­fier.

Then:

Set all EQ controls and the Boost control to 12 o’clock.
The Voicing Filters should be turned all the way down to
get a flat response. Set the Volume and Master Volumes
at 0. If you have a five string bass, push the button
marked String Bass in.

Next:

Using an instrument cable, connect your bass to the
Input jack and turn the power switch on and play. If the
input clipping LED flashes, push the button marked

10db

in. This will prevent you from overdriving the

preamp.

-

Now:

Set the volume control to 12 o’clock and slowly bring the
Master volume up. Do not turn the Volume control in
the input section past 12 o’clock unless you want an
overdrive effect. If you have a bass with passive electron­ics make sure the controls are all the way up. If you
have a bass with active electronics, turn all of the EQ
controls on the bass to the middle or flat position.

At This Point:

You should be hearing your bass quite well. You can use
the Volume and Woofer-Master to achieve a comfortable
sound level.
up the Woofer-Master control first.

Remember:

If you need more volume, turn

5

700RB Series

Sound Tips

The 700RB Series has several unique features which,
if used properly, will obtain that sound you have been
searching for.

Sound Tips

The Equalizer:

The Equalizer is used to fine tune your sound. When
adjusting it, 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, never sounds weird
and provides you with a large variety of great sounds,
unique to GK.

Contour:

Increasing the Contour level will scoop out mid-range
frequencies while boosting the highs and lows. The
sound, once again, is unique to GK and unavailable on
any other Bass amp.

String Bass:

The way a Bass amp deals with the instrument low string
is a critical part of its sound. In fact, a five string
instrument requires an entirely different low end re­sponse than a four string instrument. No equalizer can
make the necessary adjustments to accommodate both.
However, the String Bass button on the 700RB Series does
just that. When it is out, the 700RB is voiced like the
800RB (the world’s classic four string amp). Push it
in and the 700RB is voiced for five string instruments.
For some playing styles you may want it in, even with
a four string instrument.

Boost/Master:

Turning up the Boost control, will add a little growl to
your tone. This is an unmistakable GK trade mark
sound, that you will grow to appreciate. Raising the
Boost while lowering the Master will add more growl
while keeping the sound level the same. Growl is
actually a small amount of even order harmonic distor­tion, that sounds great through a woofer, but horrible
through a horn (see Bi-Amp solution below). For
most playing situations, the Master is set between 12 &
3 o’clock. The cleanest sound is obtained by setting
the Master above 12 o’clock, and going above 3
o’clock for maximum power situations.

Direct Out:

The 700RB provides a low noise, high quality bal­anced direct out 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 our
low noise, high headroom, FET input stage providing
a low noise output superior to external direct boxes
and impedance transformers. In addition, this output
is calibrated for 1.0V (0 dBV) output and can be
adjusted to unity gain (instrument level) by adjusting
the Level control to -15 dB (U) . With the switch in
the Pre position, the Direct Output signal is only
effected by the Level, -10dB Pad, and Tuning Mute
controls. 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” and preamp response to the
Direct Out jack. This gives you complete control over
the Direct Out’s tone and volume. In addition, a
Ground (Gnd) Lift switch is included to remove hum
and buzz when connecting to equipment powered by
a different ground system.

6

Bi-Amp and Normal Operation

The 700RB’s unique design allows for easy setup into Bi­Amp or Normal configurations. The operational mode is
configured by how you connect your speaker cabinets. In
addition, you have the option of driving one cabinet in
Bi-Amp and one with Normal operation.

700RB setup up for Bi-Amp Operation:

700RB Series

Bi-Amp & Normal Operation

700RB setup up for Normal Operation:

700RB setup up for Bi-Amp Operation:

The Bi-Amp feature of the 700RB series is automati­cally engaged when you connect an RBH series
cabinet (with switch on the cabinet set to Bi-Amp) to
the 700RB with the supplied 4 conductor Speakon
cable. This setup gives the 700RB complete control of
the tweeter and woofer signals sent to your rig. Now
you can push the woofers to the max., while the
tweeter remains clean, crisp and free of clipping
distortion. In addition, a smooth tight tone is easily
dialed in by adjusting the Tweeter and Woofer Master
controls on the 700RB front panel. Note: In the Bi­Amp configuration, we recommend starting with the
Woofer X-Over and Tweeter Hi-Cut controls in.

GK Speakon Cable

1+ 380W Amp +

1- 380W Amp -

2+ 380W Amp +

2- 380W Amp -

GK RBH Series Cabinet
410RBH, 210RBH,
115RBH
Set to Bi-Amp mode.

700RB setup up for Normal Operation:

The 700RB series amplifier is configured for
normal operation when you are connecting to any
cabinet with a 2 conductor Speakon cable, 1/4” to
1/4” speaker cable or 1/4” to banana plug speaker
cable. In this setup, the speaker cabinet is driven
by the 380W amp and the 50W tweeter amplifier is
not used. If you are using RBH series cabinets, the
volume of the tweeter (relative to the woofer’s
volume) can be adjusted using the Horn Level
control of the cabinet’s internal crossover.

GK Speakon Cable
1+ 380W Amp +
1- 380W Amp -

¼ Speaker Cable
Tip 380W Amp +
Shield 380W Amp -

GK RBH Series Cabinet
410RBH, 210RBH, 115RBH
Set to Full Range mode.

Any brand name cabinet with
appropriate impedance and
power rating.

7

Safety Information

700RB Series

Verify Line, Voltage and Amperage Before
Use:

Your new 700RB Series Bass Amp has been factory
configured for use with:

· 120 Volt/60Hz 20 Amp circuit for USA & Canada.

.
.

· 230 Volt/50Hz 10 Amp circuit for Europe
& Australia.

.

· 100 Volt/50Hz 20 Amp circuit for Japan.

.

· Proper AC circuit for all other countries.

Connecting the amplifier to a line with specifications
other than indicated above can create a safety and fire

Safety Information

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 multiple
amplifiers to the same circuit, or connecting the ampli­fier 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 to possibility of power variation and
electrical start-up noise affecting your sound.

Do Not Use Extension Cords:

To avoid safety hazards, use only the power cord supplied
with your unit. If a replacement cord is used, make
certain that it is of consistent quality and gauge as the
original. We do not recommend using extension cords
with this product. As with all electrical devices, do not
run power cords under rugs or carpets or place heavy
objects on them. Damaged power cords should be
replaced immediately with cords meeting factory specifi­cations.

Handle The AC Power Cord Gently:

When disconnecting the power cord from an AC outlet,
always pull the plug, never pull the cord. If you do not
intend to use the amplifier for a considerable length of
time, disconnect the plug from the AC outlet.

Do Not Open The Amplifier Enclosure:

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

Unpacking:

The carton and packing materials used in shipping your
new amplifier were specially 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.

8

700RB Series

Installation and Maintenance

Installation:

.

· To insure proper operation and to avoid
potential safety hazards, place the unit on a
firm, level surface. When installing the unit
in a rack, be sure the mounting hardware can
support the amplifier’s weight. To save space
in your rack, the 700RB’s feet can be
removed using a Philips head screwdriver.

.

· Make certain that proper space is provided for
ventilation. The 700RB Series requires at
least ½ inch clearance above for proper
ventilation. Never block the fan vent holes in
the top or front 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 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 heat sink fins and ventilation slots that
form part of the enclosure are specially
designed to remove this heat. Placing other
electronic equipment near these heat­dissipation systems may possibly affect the
long-term reliability of both your amplifier
and the other equipment.

Installation & Maintenance

Cleaning:

When the unit gets dirty, wipe it with a clean, soft and
dry cloth. If necessary, first wipe the surface with a
soft cloth slightly dampened with mild, soapy water,
followed by a fresh cloth with clean water. Wipe
immediately 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.

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.

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.

9

700RB Series

Front Panel Controls

Front Panel Controls

1-Balanced Direct Out:

An electronically balanced output, that you can run
to your P.A. system.

2-Pre/Post EQ Button:

Selects the direct out signal from before or after the EQ.

3-Direct Level Out

Controls the level at the direct out jack.

4-Input:

A standard ¼” input jack and input attenuator button.
The button is generally left out, except in rare cases when
the clip LED flashes.

5-Tuning Mute Button:

Set this switch to “On” when tuning up. No signal
will be sent to the speakers, or the P.A. system.

6-Volume:

Sets pre-amp gain after the input stage. It is used in
conjunction with the input pad, to optimize the
amplifier’s headroom.

7-Voicing Filters:
String Bass:

Setting this button voices the pre-amp for basses with
“B” tuning. Leave it out and the amp is voiced like the
800RB, for 4 string basses.

Contour:

Drops the mid-range frequencies while boosting lows &
highs.

Presence:

Adds edge and definition to higher frequencies.

Active Equalization:
8-Treble:

Boost and cut at 7 kHz +15dB shelving type. Add or
remove edge and definition.

11

12

10

1

2

4

3

6

5

7

9

8

141516

13

17

18

19

9-High Mid:

Boost and cut at 1 kHz +10dB, “Q Optimized,” band
pass type. Works on lower string harmonics, and
effects the punch of your sound.

10-Low Mid:

Boost and cut at 250Hz +10dB, “Q Optimized,”
band pass type. Works on the main body of your
sound.

11-Bass:

Boost and cut at 60Hz +10dB, shelving type. Controls
low end push.

12-Boost:

A post EQ gain stage using GIVE technology which
adds “growl” as it is turned up.

13-Tweeter/Master:

Controls output level to tweeter.

14-Tweeter Hi-Cut:

Cuts frequencies above 10kHz, producing a more
“cone” like sound from the tweeter.

15-Woofer/Master:

Controls output level of 380W amplifier. For Bi­Amp operation, this controls the woofer level.

16-Woofer X-Over:

Set this button to engage the electronic crossover
for the woofer. The tweeter is always crossed over.

17-Effects Loop:

Send and return jacks provided for the insertion of
effects after the EQ, but before the boost section.
Some effect units have gain, turning the BOOST
down, will compensate for this.

18-Tuner Output

Output to tuner.

19-Power Switch

Turns the amplifier on or off. Should a problem
occur during operation press this switch first.

10

700RB Series

3

Rear Panel Controls

Rear Panel Controls

1- AC Receptacle:

The power cord is detachable and plugs in here.

2- 380W Amp Only:

380W power amp output for Full-Range operation
only. They deliver 380 watts into 4 Ohms. Lower
impedances should not be used. Each jack has a
minimum of 8 Ohms each. Higher impedances such
as 8 Ohms, 16 Ohms, or No Load are acceptable. No
damage will result from operating the amplifier with
the speakers disconnected.

3- Speakon Outputs:

Enables BI-AMP operation by connecting a GK-RBH
Series cabinet with the provided 4 conductor Speakon
cable. This connects the 50W amplifier allowing the
Tweeter control on the front panel to control the signal
going to the horn. See Bi-Amp and Normal Operation
on page 7 for more information.

1

2

CAUTION:

UNDER NO CIRCUMSTANCES
SHOULD THE 380W AMP AND
THE 50W AMP BE CONNECTED
TOGETHER OR BE CONNECTED
TO THE SAME SPEAKER !!!

Caution:

Do not connect a Speakon cable labeled “Bridge
Mode” to the 700RB. This may result in damage to
the amplifier.

Maximum Recommended Load:

One 4 Ohm or two 8 Ohm cabinets on the 380W Amp.
One or two 8 Ohm horns on the 50W Amp.

11

11

700RB Series

700RB Series Combos

The 700RB Series combos deliver the 700RB’s unique
features and distinct sound by using a variety of
internal speaker configurations, GK’s RBH cabinet
technology and a unique Lock N’ Roll transport
system.

Speaker Configurations:

700RB/112 One 8 Ohm 12″speaker and
700RB/115 One 8 Ohm 15″speaker and

700RB Series Combos

700RB/210 Two 16 Ohm 10″speakers

The 700RB combo electronics are identical to the
700RB head and are rated for the same maximum
power output and speaker load (380W into 4 Ohms,
and 75W into 4 Ohms). Maximum power is achieved
by connecting one 8 Ohm extension cabinet (such as
the 210RBH, 410RBH, or 115RBH) in addition to the
combo’s internal 8 Ohm speaker load. To drive more
than one extension cabinet, the combo’s internal
speaker can be disconnected by unplugging the
Speakon cable connected to the combo’s back panel.
Below is a detailed description of the maximum loads
the combos can drive.

Maximum recommended load with the
internal speaker connected:

One 8 Ohm cabinet on the 380W Amp.
One 8 Ohm horn on the 50W Amp.

one 8 Ohm horn

one 8 Ohm horn

(wired in parallel for an 8
Ohm equivalent load)and
one 8 Ohm horn

Lock N Roll Transport System:

The Lock N’ Roll transport system is designed for
quick and easy rolling of the combo on flat surfaces
such as carpet, flooring, pavement, etc. To engage the
lock and roll handle, first move the combo into the
upright position (front perpendicular to the ground).
Next, stand behind the cabinet and lift the Lock N’
Roll handle up with your right hand. The handle will
lock into place after about 1 1/2 feet. Finally, grab
the handle and tilt towards the back of the combo.
The wheels on the bottom of the cabinet will auto­matically engage and allow smooth rolling.

To disengage the Lock N’ Roll system, first return the
combo to its upright position and stand behind the unit.
Next, with your left hand, pull the locking latch at the
base of the handle to your left, while pushing the handle
down gently with your right hand. Finally, push the
handle down until it stops and is flush with the top of the
combo.

The 700RB Series combos are designed for maximum
setup versatility to accommodate a variety of playing
situations. For practicing and close monitoring situa­tions, tilt the cabinet back into its “Rock Back” position.
For stronger bass and audience projection, leave the
combo in the upright position.

Maximum recommended load with the
internal speaker disconnected:

One 4 Ohm, or Two 8 Ohm cabinets on the 380W Amp.
One or Two 8 Ohm horns on the 50W Amp.

12

700RB Series

Tech Talk

Characteristics of the 700RB:

The 700RB Series is a flexible, state-of-the-art Bass
Amplifier, designed to deliver maximum performance,
and be simple to operate. This is accomplished
through a few, very important features:

.

· Extremely high current power supply and
power amp circuitry, gets the sound out of
your head.

.

· Bi-Amp sound, two power amps, 380 Watts for
the woofer, and 50 Watts for the horn.

.

· Electronic crossover, seamless two way sound.

.

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

.

· Three voicing filters for shaping and
customizing your sound.

.

· Balanced direct output with level control
eliminates need for a direct box.

.

· Continuously variable fan cooling.

.

· Designed and Built in the U.S. for years of
reliability and quality service.

Current Output & Bass Response:

When a power amplifier is pushing several speaker cones,
and a high-power transient like a string slap comes
along, the amp has to tap into a large power reserve to
maintain cone control. It’s kind of like grabbing a swing
at the bottom of it’s travel and trying to push it the other
way - it could knock you over. If the amplifier doesn’t
have this ability, the sound is unresponsive and less out
front. The amp loses it’s punch and feel at higher
playing levels. Instead of responding to your every
command, the amplifier simply cuts those transients off,
leaving you with the feeling that something is missing
in your sound.

There is nothing in the 700RB Series power amp to
come between you and your sound except faithful,
raw power.

Bi-Amp Sound:

Bass players have always liked the growl they get from
slight overdrive. In GK amps this comes partly from
the boost circuits and partly from the power amp. The
problem is that growl, sounds great through woofers, and
horrible through horns. In the typical full range system
with a passive crossover, there is no way to get growl and
keep the definition that the horn provides. The horn
always has to be turned down. In a Bi-Amp system like
the 700RB Series, the woofer and the horn, each have
their own power amp, allowing us to get growl in the
woofer only, while keeping the horn sound crystal clear.
Now you can over-drive the woofer as much as you want,
and leave the horn all the way up, keeping the definition
it brings to your sound. Running the 700RB Series in Bi­Amp mode through a GK-RBH cabinet, for the first time
allows full access to the benefits of Bi-Amp sound. This is
the reason the 700RB Series is a Bi-Amp, and it is the
reason you will be able to explore an entirely new
territory of Bass sound.

Tech Talk

Since most amplifiers have limited output current
capacity, they need “current limiting circuits” to
protect against self-destruction. High-power tran­sients trigger these circuits, which rob the amplifier of
it’s ability to control speaker cones. This creates a
mushy, unresponsive feel to your sound. The 700RB
Series has extremely high current capacity, so it
doesn’t need current limiting circuits for over-load
protection.

13

Tech Talk

700RB Series

Tech Talk

Electronic Crossover:

Bi-Amp systems allow the crossover to be electronic
and therefore, have much higher quality than passive
crossovers. A crossover separates the sound into two
parts (high and low frequency). The highs are sent to
the horn or high frequency cabinet and the lows are
sent to the woofer. In an ideal system, adding the
highs and the lows back together would recover the
original signal. Most passive Bass systems have very
poor crossovers, resulting in severe signal corruption.
When these signals are added back together (as in
your ear), they have very little in common with the
original signal. The 700RB Series uses a Constant
Voltage crossover which results in very little signal
corruption. In fact, when the high and low signals
are added back together, the result is extremely close
to the original. This makes a two-way system sound
more seamless, and less artificial. We have also
included a Tweeter Hi-Cut switch in the crossover,
which rolls the tweeter off above 10kHz giving it a less
glassy, more cone like sound.

Equalization:

The sound you want is in your head, but you just can’t
get it. You think it’s you, your bass or maybe your amp.
Yes, your amp. Standard tone controls and graphic
equalizers don’t get it. Sure, they 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, and are only put in bass amps
because it’s a no-brainer for the designer. The equaliza­tion in Gallien-Krueger amplifiers reflects 30 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 doesn’t sound weird at any setting. You actually
might even get to hear that sound in your head.

Voicing Filters:

Voicing filters are used to completely re-voice the
amplifier. In the case of the Contour and String Bass
controls, the effect is dramatic.

The Contour control tunes between two different shaping
circuits, with greatly different response. 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 a
response contour not available with a normal equalizer,
and is only found in GK amplifiers.

The way a Bass amp deals with the instrument low string
is a critical part of it’s sound. In fact, a five string
instrument requires an entirely different low end re­sponse than a four string instrument. No equalizer can
make the necessary adjustments to accommodate both,
however the String Bass button on the 700RB Series does
just that. When it is out, the 700RB is voiced like the
800RB (the world’s classic four string amp). Push it
in and the 700RB is voiced for five string instruments.
For some playing styles you may want it in, even with
a four string instrument…at least now, you have a
choice!

G.I.V.E. Technology:

As in all GK pre-amps, the 700RB 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.

14

Tech Talk

700RB Series

Cool Running = Reliability:

The 700RB Series uses a “dual rail power supply” that
generates about half the heat of conventional amplifiers.
Low output signals run off a low voltage supply, and high
level signals run off a high voltage supply. This keeps
the amp running a lot cooler and makes it much more
reliable. 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 700RB’s protection circuitry constantly monitors for
unsafe operating conditions such as short circuits, miss­wired speaker cables, blown speakers, improper ventila­tion and incorrect speaker configurations. In addition,
protection is provided during power up/down. If the
700RB senses any unsafe operating conditions, the
output signal is immediately muted and the power light
changes to from Green 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. Also, check to see that you
have connected the amplifier to your speakers as de­scribed in Bi-Amp and Normal Operation on page 7. If
the problem persists, contact GK directly for advice.

Speakon Cables:

To make use of the 700RB’s Bi-Amp feature you will
need to use the four conductor Speakon cable (provided
with the 700RB head, and included with the combos for
connection to the internal speaker) to connect to a GK
RBH Series cabinet. This specially designed cable carries
the signals for both amplifiers (380W Woofer Amp and
50W Tweeter Amp) to the speaker cabinet. Plus, they are
the coolest speaker connectors currently available. Below
is a table describing the Speakon cable connections to the
700RB head and combos.

Speakon Pin # Signal WireColor
1+ 380W Woofer Amp + White
1- 380W Woofer Amp - Black
2+ 50W Tweeter Amp + Red
2- 50W Tweeter Amp - Green

To obtain an additional 4 conductor Speakon cable for
use with the 700RB please contact your local
dealer or contact GK directly.

In Closing:

You should now have a thorough understanding of how
your new 700RB 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].

Tech Talk

Low Noise Operation:

The 700RB Series uses a high gain, high headroom,
low noise input stage. It has such a large dynamic
range (60v p-p) that very few instruments can
overdrive it. Even most basses with “active” electron­ics do not need the input attenuator to be set. The
benefit to you is less hiss from your horn, and over all,
much less noise.

15

Block Diagram

Specifications

700RB Series Specifications:

700RB Series

Output Power:
380W Amplifier 225W @ 8 Ohms

380W @ 4 Ohms

50W Amplifier 50W @ 8 Ohms

75W @ 4 Ohms
Input Section:
Maximum Input Level 0.6V Rms
With -10dB pad 1.6V Rms
Input Impedance 1M Ohm
Send output impedance 220 Ohm
Return input impedance 50k Ohm
Tuner Output Impedance 10k Ohm
Direct Output Impedance 500 Ohms
Equalizer:
Bass +10db @ 60Hz
Lo-Mid +6db/-10db @ 250Hz
Hi-Mid +6db/-10db @ 1kHz
Treble +14db @ 7kHz
Voicing Filters:
String Bass Button +11db@20Hz
Contour +2db@50Hz /

-10db@500Hz /

+3db@7kHz
Presence +9db@10kHz
Crossover Triple pole constant

voltage crossover at 5kHz
Noise -90db referenced to 380W,

“A” weighted

Cooling Continuously Variable-

Speed Fan

Amplifier Protection:

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

Dimensions (HxWxD):

3 1/2” x 17” x 8 ¼”
(2 Rack Spaces)

Weight:

18lbs

Power Requirements:

U.S.A./Canada 120V/60Hz

615W (full power)
210W(average power)

Europe 230V/50Hz

615W (full power)
210W (average power)

Japan 100V/50Hz

615W (full power)
210W (average power)

16

700RB Series Owners Manual

Part #160-0001-B

Printed in the U.S.A.