Rolls RA280 User Manual
SPECIFICATIONS
Power Output, Stereo: 80 Watts RMS/ch. 4 Ω
50 Watts RMS/ch. 8 Ω
Bridged 150 Watts RMS 8 Ω
Sensitivity: <1 VRMS for full output
THD, IMD: <.08% (1kHz @ 1 Watt).05%
S/N Ratio: 106 dBU
Power Bandwidth: 50 Hz - 25 kHz +/- 1dB
Damping Factor: > 150
Slew Rate: 100 Volts/microSecond
Phase Shift: <10 Deg., 20Hz - 20kHz
Input Impedance: 10 KΩ Balanced
Power: 120 VAC 60Hz 2.5A
230 VAC 50Hz
Size: 19” x 3.5” x 7.5”
(48 x 9 x 19 cm)
Weight: 12 lbs (5.5 kg)
LIMITED WARRANTY
This product is warranted to the original consumer purchaser to be free from
defects in materials and workmanship under normal installation, use and service for a
period of one (1) year from the date of purchase as shown on the purchaser’s receipt.
The obligation of Rolls Corporation under this warranty shall be limited to
repair or replacement (at our option), during the warranty period of any part which
proves defective in material or workmanship under normal installation, use and service,
provided the product is returned to Rolls Corporation, TRANSPORTATION CHARGES
PREPAID. Products returned to us or to an authorized Service Center must be accompanied by a copy of the purchase receipt. In the absence of such purchase receipt, the
warranty period shall be one (1) year from the date of manufacture.
This warranty shall be invalid if the product is damaged as a result of
defacement, misuse, abuse, neglect, accident, destruction or alteration of the serial
number, improper electrical voltages or currents, repair, alteration or maintenance by
any person or party other than our own service facility or an authorized Service Center,
or any use violative of instructions furnished by us.
This one-year warranty is in lieu of all expressed warranties, obligations or
liabilities. ANY IMPLIED WARRANTIES, OBLIGATIONS, OR LIABILITIES,
INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, SHALL BE
LIMITED IN DURATION TO THE ONE YEAR DURATION OF THIS WRITTEN
LIMITED WARRANTY. Some states do not allow limitations on how long an implied
warranty lasts, so the above limitation may not apply to you.
IN NO EVENT SHALL WE BE LIABLE FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES FOR BREACH OF THIS OR ANY OTHER
WARRANTY, EXPRESSED OR IMPLIED, WHATSOEVER. Some states do not allow
the exclusion or limitation of special, incidental or consequential damages so the above
limitation or exclusion may not apply to you. This warranty gives you specific legal
rights, and you may also have other rights which vary from state to state.
RA280
Po wer Amplifier
80 Watt Stereo
150 Watt Bridged
VOLUME 1
1 4 28 80
WATTS 4 Ohms
M
OSFET POWER AMPLIFIER
VOLUME 2
PWR
1 4 28 80
WATTS 4 Ohms
RA280
Rolls Corporation
Salt Lake City, UT
12/98
OWNERS MANUAL
Thank you for your purchase of the Rolls RA280 Power Amplifier. The
RA280 is a stereo 80 Watt/channel RMS power amplifier in a standard 2
rack space format. It is intended for professional audio, musical, and
studio applications. The unit features 80W per channel RMS into four
ohms, 50W per channel RMS into eight ohms, and 150 watts into eight
ohms bridged.
The unit also features MOSFET drivers in a voltage and current gain
circuit, a one-second input turn on delay, and LED power output meters.
The RA280 is built solid and has a painted steel chassis, special highperformance transformers and a fused power line. The MOSFET output
stage is fault protected and helps the RA280 forgive output shorts.
INSPECTION
1. Unpack and Inspect the RA280 package
Your RA280 was carefully packed at the factory in a protective carton.
Nonetheless, be sure to examine the unit and the carton for any signs of
damage that may have occurred during shipping. If obvious physical
damage is noticed, contact the carrier immediately to make a damage
claim. We suggest saving the shipping carton and packing materials for
safely transporting the unit in the future.
2. Please complete the Warranty Registration Card and return it to the
factory.
INSTALLATION
Connect the power cord to an AC power source, connect the input to the signal
source and to the RA280 via the RCA or 1/4" input jacks . Speakers may be
connected by using 1/4" jacks, or the dual banana posts which are preferred.
When using in bridged mode, the banana connectors must be used.
Turn the Volume controls fully counterclockwise (off), and turn on the power
switch, the power LED should light. With the program material running, slowing
increase the Volume controls until the desired level of sound is present.
We've included the one second turn-on delay to prevent possible speaker
damage in case all equipment is on a single power strip.
FAULT PROTECTION
The fault protection in the RA280 limits the current to the output stage in the
faulted channel and turns on all the LEDs in that channel. This mode is entered
whenever the output stage is called upon for too much power, it may also be
fooled by impedances lower than four ohms which may cause the output stage
to overheat and burn up the MOSFETs.
IMPORTANT: Since the RA280 is convection cooled, the unit radiates heat from
the rear and, depending on it's load demand, it may become very hot if drawn
upon heavily.
Should the unit need service, contact Rolls directly, obtain a Return Authorization number (RA Number), and return the unit to us for repair.
SCHEMATIC
4A 120V - 2A 230 V
MAINS POWER
OUTPUT 2 OUTPUT 1
WARNING
For continued prootection against
risk of fire, replace only with
same type and rating of fuse.
RISQUE DE CHOC - NE PAS ENLEVER
-
OUTPUT 1
+
+
OUTPUT 2
-
SERIAL NUMBER
MADE IN U.S.A.
CHANNEL 2 INPUT CHANNEL 1 INPUT
BRIDGE NORMAL
CORPORATION
CAUTION
TO REDUCE THE RISK OF ELECTRIC
SHOCK DO NOT NOT REMOVE LID. NO
USER SERVICABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED
SERVICE PERSONNEL
WARNING:
To reduce the risk of electric
shock or fire do not expose
this device to rain or moisture.
BRIDGING
To bridge the RA280, move the Bridging switch to the "Bridge" position. The
Channel 1 knob controls the level of the bridged output, Channel 2 knob is
inactive.
Connect the input to Channel 1 input, then connect the load to the two positive
(red) banana jacks. Make no connections to the black banana jacks. The level
meters will both light, and the output power into 8 ohms is the sum of the LEDs
that light.
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