Схема и документация усилителя Other GENERALMUSIC P500

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TECHNICAL SPECIFICATIONS
TECHNICAL SPECIFICATIONS
TECHNICAL SPECIFICATIONS
TECHNICAL SPECIFICATIONS
TECHNICAL SPECIFICATIONS
Dimensions:
483x88x325mm (2U)
Power Requirements:
(230Vac±10% 50Hz)
Output Power:
stereo/parallel)
2x 300Watts
stereo/parallel)
2x 200Watts
Max. Undistorted Out: (4
stereo/parallel)
stereo/parallel)
Input Sensitivity:
(constant sensitivity)
0.775Vrms (0dB)
(constant gain)
1.75Vrms (+7dB)
Input Impedance:
(unbalanced)
Voltage Gain:
(constant sensitivity)
(constant gain)
Damping Factor:
stereo/parallel)
stereo/parallel)
Frequency Response
at Full Power:
(SMPTE 60Hz/7KHz 4:1)
(unweighted)
TEST PROCEDURES & ADJUSTMENTS
TEST PROCEDURES & ADJUSTMENTS
TEST PROCEDURES & ADJUSTMENTS
TEST PROCEDURES & ADJUSTMENTS
TEST PROCEDURES & ADJUSTMENTS
µ To prevent short circuit during any test, the oscilloscope must be
the oscilloscope must be
the oscilloscope must be
the oscilloscope must be
the oscilloscope must be
EARTH insulated
EARTH insulated
EARTH insulated
EARTH insulated
EARTH insulated, this occurs because some test require to connect itsprobe to the amplifier output, non-compliance may cause damages tooscilloscope inputs circuitry.
µ Before removing or installing any modules and connectors, disconnect
the amplifier from AC MAINS
the amplifier from AC MAINS
the amplifier from AC MAINS
the amplifier from AC MAINS
the amplifier from AC MAINS and measure the DC supply voltagesacross each of the power suppliy capacitors. If your measurement on anyof the caps is greater than 10Vdc, connect a 100
20W resistor across
the applicable caps to discharge them for your safety. Remember toremove the discharge resistor immediately after discharging caps. Do not
power up the amplifier with the discharge resistor connected
power up the amplifier with the discharge resistor connected
power up the amplifier with the discharge resistor connected
power up the amplifier with the discharge resistor connected
power up the amplifier with the discharge resistor connected.
µ Read these notes entirely before proceeding to any operation. These
notes are not comprehensive of all damages that possibly occur, butincludes some specifically advices, checks and adjustments relative tothis amplifier.
µ The power supply utilizes a dual bipolar DC rail configuration with low and
high voltages; one positive and one negative low rail (+/-Vcc1) and onepositive and one negative high rail (+/-Vcc2).
Visual Check
Visual Check
Visual Check
Visual Check
Visual Check
µ Use compressed air to clear dust in the amplifier chassis.
µ Before proceed to supply the amplifier check visually the internal assem-
bly, if appears an evident damage find the most possible reasons thatcause it.
µ Check the wiring cables for possible interruptions or shorts.
µ If the damage has burnt a printed circuit board don't try to repair it, re-
place with a new one.
Test Instruments
Test Instruments
Test Instruments
Test Instruments
Test Instruments
µ Audio Generator
µ Dual Trace Oscilloscope
µ Digital Multimeter
20W resistors
µ Variac (0?250Vac)
µ Temperature Meter
µ Connect the Variac between the mains and the amplifier and set it at zero
µ Set the amplifier in STEREO MODE and turn full clockwise the LEVEL
potentiometers.
µ Connect the audio generator to the channel inputs and set it to 1KHz
(0dB) sinusoidal signal.
µ Insert the temperature meter through the IC3 interstice located at centre
of heatsink.
µ The procedures that follow must be executed subsequently in the order
Supply Check
Supply Check
Supply Check
Supply Check
Supply Check
µ Remove the transformer secondary fuses (located on SUPPLY & PRO-
TECTIONS board), set the Variac to the nominal mains voltage, checkwith the Multimeter the AC supply voltages:
F1-F2=52±2Vac
F3-F4=90±3Vac.
µ Re-set the Variac at zero voltage, turn off the amplifier and put the fuses
back on its holders.
µ Connect the oscilloscope probes CH1/2 to the channel outputs, before
RL1 and RL2, set both to 20V/div. 200
µ Set up the Variac slowly monitoring the Outputs with the oscilloscope
CH1/2 connected, it should display the sinusoidal input signal amplifiedwith no distortions, if a distortion occur check the POWER AMPLIFIERboards as suggested in the ADVICES section.
µ If the protection trips, turn off the amplifier, wait some minutes and
disconnect the supplies from the outputs modules (CN2, CN3 on POWERAMPLIFIER boards), continue to check the supplies.
µ CAUTION: Before re-connecting the output modules to the supplies,
CAUTION: Before re-connecting the output modules to the supplies,
CAUTION: Before re-connecting the output modules to the supplies,
CAUTION: Before re-connecting the output modules to the supplies,
CAUTION: Before re-connecting the output modules to the supplies,you must have the capacitors discharged for your safety: connect a
you must have the capacitors discharged for your safety: connect a
you must have the capacitors discharged for your safety: connect a
you must have the capacitors discharged for your safety: connect a
you must have the capacitors discharged for your safety: connect a100
20W resistor across the caps and remove the resistor just after
20W resistor across the caps and remove the resistor just after
20W resistor across the caps and remove the resistor just after
20W resistor across the caps and remove the resistor just after
20W resistor across the caps and remove the resistor just after
they are discharged.
they are discharged.
they are discharged.
they are discharged.
they are discharged.
µ Finally verify the DC supplies on SUPPLIES & PROTECTIONS Board:
=+35±1.5Vdc
=-35±1.5Vdc
CN3 pin3-4-5 =+15±1VdcCN3 pin8-9-10 =-15±1Vdc
µ If one or more voltages don't correspond, check the rectifiers, capacitors
and transformers disconnecting them from circuitry, refer to schematics.
Channels Check
Channels Check
Channels Check
Channels Check
Channels Check
µ The channel A is facing the front and channel B the rear of the chassis.
µ These procedures are intended for one channel at a time, repeat these
operation for the other channel.
µ Verify, with the Multimeter, the insulation between the heatsink and the
transistors collectors.
SETUP:Connect the CH1 scope GND clip to CN3 pin 1 (GND terminal).Connect the CH1 probe tip to CN3 pin 2 (AMP output).Connect the CH2 probe tip to D20 cathode.Set the LEVEL potentiometers full clockwise.The load resistor is disconnected.
µ INITIAL TEST:
INITIAL TEST:
INITIAL TEST:
INITIAL TEST:
INITIAL TEST:Increase slowly the Variac. The channel output signals must be symmetri-cal respect the GND without visible distortion and oscillation as shown inFig.1 Trace A. If there is a distortion read the section ADVICES andproceed to check the other channel.Verify that, when the heatsink temperature is less than 50°c, the coolingfan voltage must be between 10 and 14Vdc.
µ HIGH RAIL CHECK:
HIGH RAIL CHECK:
HIGH RAIL CHECK:
HIGH RAIL CHECK:
HIGH RAIL CHECK:When the output signal (Positive half-wave) is less than 30Vp the voltageon D20 cathode must remain constant at 36V, when the output signalexceeds 30Vp the voltage must follow the output signal with 6V offset(see
Fig.1 Trace B), to check the negative high rail connect the probe to
D30 anode (see
Fig.1 Trace C).
Connect the 4
500W load on the output and repeat the INITIAL and
HIGH RAIL checks.Check the signal clipping, it must occur at 48±2Vpp (see
Fig.2 Trace
Trace B (20V/div.)
Trace A (20V/div.)
Trace C (20V/div.)