Welcome; Unpacking; Features; Power Base Front And Back Panels - Crown POWER BASE 1 Reference Manual

Power Base Series Power Amplifiers
MODEL: POWER-BASE™ 3 12.5 AMPS
AC VOLTS: 120
MAXIMUM OUTPUT: 700 WATTS
PER CHANNEL INTO 4 OHMS AT 1 KHz
WITH NO MORE THAN 0.1% THD.
ELECTRONIC EQUIPMENT
ELKHART, IN 46517
MADE IN U.S.A.
SERIAL NUMBER
WARNING:
TO
REDUCE THE RISK OF
FIRE OR ELECTRIC
SHOCK, DO NOT EXPOSE
THIS EQUIPMENT TO
RAIN OR MOISTURE.

1 Welcome

Congratulations on choosing a Power Base amplifier.
Power Base amplifiers are compact, professional ste-
reo power amplifiers engineered to meet the most de-
manding sound reinforcement needs. They compare
very favorably to more expensive amplifiers, providing
uncolored sound and signal-to-noise ratios commonly
associated with recording studios.
This manual will help you successfully install and use
your amplifier—we strongly recommend you read all
instructions, warnings and cautions. If you plan to oper-
ate in one of the two mono modes, be sure to read Sec-
tion 2.2. Also for your protection, please save your bill
of sale as it is your official proof of purchase.

1.1 Unpacking

Please unpack and inspect your new amplifier for any
damage that may have occurred during transit. If dam-
age is found, notify the transportation company imme-
diately. Only you, the consignee, may initiate a claim
with the carrier for damage resulting during shipment.
Even if the unit arrived in perfect condition, as most do,
save all packing materials so you will have them if you
ever need to transport the unit. NEVER SHIP THE
UNIT WITHOUT THE FACTORY PACK.
Reset Power Access
Switch Cord Cover
(Power Base–3 Only)
PUSH TO RESET
60 Hz
CAUTION:
THIS COVER IS NECESSARY FOR
EFFICIENT COOLING OF THE AMPLIFIER.
REMOVE ONLY TO ACCESS GAIN SWITCH.
® INTERNATIONAL, INC.
0000
000000
THIS AMPLIFIER IS EQUIPPED WITH SELECTABLE INPUT SENSITIVITY. REMOVE COVER PLATE (ABOVE) TO ACCESS SENSITIVITY SWITCH.
CH-2
6
5 7
4 8
STEREO
9
3
BALANCED
PARALLEL BRIDGE
2 10
INPUT WIRING
MONO MONO
1 11
+
TIP
0 12
REG. U.S. PAT. OFF.
4,330,809 CAUTION: – GAIN
TURN OFF AMPLIFIER RING
4,611,180 BEFORE CHANGING THIS SWITCH!
GND SLEEVE
Stereo/Mono Ch.2
Switch Level
Control
Fig. 1.1 Power Base Front and Back Panels
Removable grille 5-Way Binding Post
and dust filter Output Connectors
OUTPUTS
CLASS 2
OUTPUT
WIRING
REQUIRED.
BRIDGE-MONO WIRING
CH-1
1 TURN AMPLIFIER OFF.
6
5 7 2 SET STEREO/MONO
4 8 SWITCH TO
9 BRIDGE-MONO.
3
UNBALANCED
2 10 3 OUTPUT ACROSS
INPUT GROUND LIFT INPUT WIRING
RED TERMINALS
1 11
+
TIP
LIFT 0 12 ONLY. (CH-1
INPUT INPUT
IS POSITIVE.)
GAIN
(AFFECTS PHONE INPUTS ONLY.) (MONO)
GND SLEEVE
Ch.2 Ground Ch.1 Ch.1
¼ Inch Lift ¼ Inch Level
Phone Switch Phone Control
Input Input

1.2 Features

Rugged, professional power amplifier built for the road.
Mounts in a standard 19 inch (48.3 cm) rack.
Crown's patented grounded bridge circuitry gener-
ates large voltage swings while avoiding electrical
stress on the output stages. This results in low distortion
and high reliability.
Front panel power switch with turn-on delay for loud-
speaker protection.
Patented Output Device Emulation Protection ( ODEP
keeps the amplifier working when others would fail.
High damping factor provides superior control over low
frequency drivers for a clean, accurate low end.
Safe with any load. Bridge-Mono and Parallel-Mono
modes offer optimal load-matching performance.
Complete protection against shorted outputs, mis-
matched loads, overheating, DC input/output and high-
frequency overload; full internal fault protection.
Balanced phone jack inputs with internal three-position
sensitivity switch. Optional XLR or barrier block input
connectors are available with the MT-XLR or MT-BB ac-
cessories.
Ground lift switch is provided to isolate the chassis
ground from the phone jack input ground.
Efficient heat sinks and self-contained forced air cool-
ing system dissipate heat quickly and evenly for extra
amplifier protection and greater power output.
Three year "No-Fault" full warranty and guaranteed
specifications protect your investment.
Power
Power
Indicator Switch
POWER
OFF
CAUTION:
TO PREVENT ELECTRIC
SHOCK DO NOT REMOVE TOP OR BOTTOM
COVERS. NO USER SERVICEABLE PARTS
INSIDE. REFER SERVICING TO QUALIFIED
SERVICE PERSONNEL. DISCONNECT POWER
CORD BEFORE REMOVING REAR COVER
PLATE TO ACCESS SENSITIVITY SWITCH.
ATTENTION:
DÉBRANCHER AVANT
D'OUVRIR.
CH-2 CH-1
PARALLEL-MONO WIRING
+
–
1
TURN AMPLIFIER OFF.
2 SET STEREO/MONO SWITCH
TO PARALLEL-MONO. –
+
3 ADD JUMPER (14
GAGE OR LARGER)
ACROSS RED TERMINALS.
4 OUTPUT ACROSS CH-1
TERMINALS ONLY.
® )
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