monophonic or single channel amplifier. The amplifier can be used only
with 8 Ohm or higher loads in M
B
ONO
used to provide a higher power output with greater headroom to your
speaker. Before setting your amplifier for M
sure that your speaker can handle the high power level provided by the
amplifier in M
mode.
B
ONO
RIDGE
CAUTION:
100 V
OVER
MAY BE PRODUCED AT THE BRIDGE OUTPUT TERMINALS IN
. M
THIS MODE
AKE SURE THE POWER IS OFF BEFORE SETTING THE OPERATION MODE
(8)
.
SWITCH
TO THE BRIDGE POSITION
With the power O
, connect your input cable to CH 1 input only, using
FF
the XLR B
(10) or ¼" TRS B
I
ALANCED
NPUT
ALANCED
Connect the loudspeaker to the B
RIDGED
sure the polarity of your connection is correct.
NOTE:
THE TOTAL SPEAKER LOAD MUST BE AT LEAST
8 O
M
TRY TO OPERATE AT LESS THAN
HMS IN THE
&
FIER WILL GO INTO PROTECT MODE
CEASE OPERATION UNTIL YOU CORRECT THE
.
LOAD CONDITIONS
With the CH 1 (13) volume rotary control set to zero (fully counterclock-
wise), push the P
B
(11) to turn O
OWER
UTTON
to the input. The level of the input signal should be as high as you will ever
need it to be. This way, it will be as high above the amplifier's noise floor
as possible, ensuring an excellent performance & signal to noise ratio.
Adjust the CH 1 (13) volume rotary control to achieve the desired maxi-
mum listening level.
NOTE:
,
WHEN THE CLIP LEDS LIGHT
THERE IS DISTORTION PRESENT IN THE AMPLI
'
.
FIER
S OUTPUT SECTION
IF A CLIP LED REMAINS ON OR FLASHES REPEATEDLY
REDUCE THE SIGNAL LEVEL BY LOWERING THE INPUT LEVEL CONTROL FOR CH
.
REDUCE THE LEVEL AT THE SOURCE
DURING MONO BRIDGE OPERATION
;
,
'
LEVEL IS INACTIVE
HOWEVER
BOTH CHANNELS
LEDS WILL FLASH SIMULTANEOUSLY
&
.
SHOW OUTPUT CONDITIONS
2. P
B
: Once all of your connections have been made in the rear
OWER
UTTON
panel and your operations settings are made, turn on the amplifier by
pressing the P
(11). The P
B
OWER
UTTON
OWER
& O
. The P
B
(11) LED lights when the power is on. If the LED
FF
OWER
UTTON
does not light, refer to the troubleshooting guide.
3. G
: The G
L
S
L
S
ROUND
IFT
WITCH
ROUND
IFT
WITCH
anced input connectors' ground/shield from the amplifier's ground. When
the signal ground lifted, the sound source disconnects from the
amplifier's ground preventing ground loops which can generate
hum & noise. Depending on your system's configuration, applying the
ground may create a quieter signal path. Sometimes lifting the ground can
eliminate ground loops & hum to create a quieter signal path.
With the power amplifier O
, listen to the system in idle mode (no signal
N
present) with the ground applied (the G
ROUND
position).
Turn the power O
before moving the G
FF
ROUND
ground by moving the G
(7) to the right, turn the power
L
S
ROUND
IFT
WITCH
back on & listen to determine which position will provide a signal free of
background noise & hum. Keep the G
ROUND
position if the noise level remains the same in either position.
mode. This mode is
CAUTION:
RIDGE
.
WAY
TERMINATION OF THE AC GROUND CAN BE HAZARDOUS
B
operation, make
ONO
RIDGE
4. D
ECIBEL
bel (dB) level as well as clipping.
NOTE:
IN MONO BRIDGE MODE
CLIPPING OCCURS
speakers especially if the distortion is hard and frequent. The
amplifier has true Clip LEDs to help you monitor the amplifier's
(9) of CH 1.
I
NPUT
output & achieve undistorted sound. The Clip LED for each chan-
O
S
(5) only. Be
nel lights when your signal level is so strong that the distortion reaches 1%
UTPUT
PEAKON
THD. The Clip LED should not remain constantly O
8 O
. I
during operation.
HMS OR ABOVE
F YOU
B
,
-
For clean sound reproduction, the Clip LED should only light occasional-
ONO
RIDGE MODE
THE AMPLI
ly for an instant. If the LED remains on or flashes repeatedly, you will hear
distorted sound that can be damaging to your speaker system. If this
occurs, reduce the signal level by lowering the input volume rotary control
the amplifier. Apply a signal
for the channel that is clipping or reduce the level at the source.
N
If the Clip LED lights when no signal is present, it may indicate an RF sig-
nal on the output which may cause damage to speakers (the RF signal will
not be audible).
5. V
: CH 1 (13) & CH 2 (14) volume rotary control establish the
OLUME
input levels required for each channel. Only the CH 1 (13) volume rotary
-
control works in M
,
6. P
ROTECT
1
OR
hensive protection circuitry to ensure the reliability &
,
2
THE CH
longevity of your unit. These include Short Circuit, DC,
Thermal Cut-off, Sub/Ultrasonic Frequency Filters, Turn-
on Delay, Main Fuse, & Secondary DC Fuses.
lights briefly during a turn-on delay which indicates that the out-
(11) turns the unit O
B
UTTON
N
puts are disconnected internally. There will be an audible click when the
outputs reconnect & the P
P
LED (12) indicates that there is a problem either in the amplifier's
ROTECT
(7) is used to lift the bal-
external connections, load or temperature conditions, or its internal func-
tions. If one of these situations occurs, the amplifier senses the problem &
automatically switches into protection mode.
The P
ROTECT
fier will stop outputting signal. If this occurs, switch off the amplifier &
refer to the Troubleshooting Guide. If the P
when resuming amplifier operation, do not use the amplifier & contact an
authorized service technician.
(7) in the left
L
S
IFT
WITCH
NOTE:
THE PROTECT LED
The GPA S
L
S
(7). Lift the
IFT
WITCH
mounting of the unit in a standard, 19-inch equipment rack. Use a Philips-
head screwdriver along with the supplied mounting hardware to attach the
R
E
.
ACK
ARS
L
S
(7) in the ground
IFT
WITCH
DO NOT DEFEAT THE AC GROUND PIN ON THE POWER CABLE IN ANY
.
: The D
(15) indicates the audio signal's deci-
M
M
ETER
ECIBEL
ETER
,
1,
2
BOTH THE CH
CH
METERS
)
.
WILL OPERATE SIMULTANEOUSLY
Clipping refers to audible distortion that can be damaging to
N
mode.
B
ONO
RIDGE
LED: The GPA series features several types of compre-
When you first turn O
the amplifier, the P
N
LED (12) will turn O
ROTECT
LED (12) will light to warn you of the trouble & the ampli-
LED (12) remains lit
ROTECT
(12)
GPA-1000.
IS NOT INCLUDED ON THE
amplifiers come supplied with R
ERIES
ACK
<5>
SPECIFICATIONS:
1000
Output Power EIA:................................................1 kHz at 1% THD, WRMS
&
(
CLIP LEDS
WHEN
Both Channels Driven at 8 Ohms
70
Both Channels Driven at 4 Ohms
90
Mono Bridge at 8 Ohms
180
or flash repeatedly
Dynamic Headroom, dB:..............................................................at 8 Ohms
1.3
......................................................................................................at 4 Ohms
1.8
Frequency Response..............................................................30 Hz - 50 kHz
Total Harmonic Distortion............Less than 0.05%, typical 0.02% at 1 kHz
Signal to Noise ratio..........................100 dB below rated power at 8 Ohms
Damping factor..................................................greater than 200 at 8 Ohms
Slew rate...........................................................................................20 V/µS
Voltage gain..............................................................................................dB
27
Input Sensitivity (for rated power at 8 Ohms)..................................1 VRMS
Input Impedance Unbalanced......................................................10 kOhm
Input Impedance Balanced............................................................20 kOhm
Power consumption (at rated power at 4 Ohms, both channels driven)...W
400
AC Power Requirements....................110-120 V / 60 Hz ; 220-240 V / 50 Hz
Indicators:................................................................................1 Power LED
LED (12)
ROTECT
.................................................................1 Protect LED (except GPA-1000)
..................................................................................VU-meter per Channel
. Otherwise, the
Cooling...........................................................Fan, Front-to-Rear Forced Air
FF
Protection:............................................Short Circuit, DC, Thermal Cut-off,
.................................................................Sub/Ultrasonic Frequency Filters,
...........................................Turn-on Delay, Main Fuse, Secondary DC Fuses
C
:
ONNECTORS
Balanced/Unbalanced inputs.................................................XLR & ¼" Jack
Speaker Outputs:..........................................................Speakons & ¼" Jack
D
:
IMENSIONS
GPA series.............................19"W x 10.75"D x 3.5"H (483 x 273 x 89 mm)
Weight.........................................................................................................
13.6 lbs
E
to allow the
ARS
6.2 kg
S
&
PECIFICATIONS
DESIGN ARE SUBJECT TO CHANGE WITHOUT NOTICE FOR PUR
.
POSE OF IMPROVEMENT
GPA Series
2000
3000
85
140
110
200
220
400
1.4
1.5
1.9
2.0
28
30
500
800
16.5 lbs
18.3 lbs
20.2 lbs
7.5 kg
8.3 kg
4 0 0 0
200
300
600
1.6
2.2
32
1200
9.2 kg
-