15
700RB-II/1001RB-II Series
Tech Talk
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 is used to completely revoice the ampli-
fier. 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 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 1001RB-II/700RB-II Series does just that.
When it is out, the 1001RB-II/700RB-II is voiced like
the 800RB. Push it in and the 1001RB-II/700RB-II is
voiced for five string instruments. For some playing
styles you may want it in, even with a four string
instrument.
Low Noise Operation:
The 1001RB-II/700RB-II Series uses a high gain,
high headroom, low noise input stage. It has such a
large dynamic range (60v p-p) that very few instru-
ments 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.
“G.I.V.E.” Technology:
As in all GK pre-amps, the 1001RB-II/700RB-II 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. Work-
ing 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.
Cool Running = Reliability:
The 1001RB-II/700RB-II 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 1001RB-II/700RB-II’s 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 1001RB-II/
700RB-II 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 techni-
cal advice.
Speakon Cables
:
To make use of the 1001RB-II/700RB-II’s Bi-Amp
feature you will need to use the four conductor
Speakon style cable (provided with the 1001RB-II/
700RB-II head, and built into the combos for connec-
tion to the internal speaker) to connect to a GK RBH/
SBX Series cabinet. This specially designed cable
carries the signals for both amplifiers (700W/480W
Woofer Amp and 50W Tweeter Amp) to the speaker
cabinet. Below is a table describing the Speakon
cable connections to the 1001RB-II/700RB-II head
and combos.
Speakon Pin #
Signal
1+
Woofer/Main Amp +
1 -
Woofer/Main Amp -
2+
50W /Tweeter Amp +
2 -
50W /Tweeter Amp -
To obtain an additional 4 conductor Speakon cable
for use with the 1001RB-II/700RB-II please contact
your local dealer or contact GK directly.
In Closing:
You should now have a thorough understanding of
how your new 1001RB-II/700RB-II 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 [email protected].
