SMPTE-IM
2OHz to 2OkHz,
8Hz to 5OkHz, +Ol-3dB
Greater
106dB
6k unbalanced,
Standard 19” Rack Mounting
3.Y
13.2Y
2119.5 2119.5
Less
than
+I-0.2dB
than
500
below rated output (20 Hz to 20 kHz)
12k
balanced
602
300
waKs
500
watts
1100
watts1500 watts
32
1.20 Vrms
0.01%
3.r
13.2v
PLX2402
425watts 550
700
watts 900watts
32
1.50 Vrms
3.5” 3.Y
13.2Y13.2Y
2119.5
PLX3002
2000 watts
32
1.70
2119.5
watts
vrms
Page 6
Introduction
This manual is prepared to assist service personnel with the repair and calibration of PLX power
amplifiers
and sophisticated audio test equipment.
Documentation
This manual contains schematics, printed circuit board (PCB) drawings, parts lists, and
mechanical assembly drawings. This information should be used in conjunction with the
test and troubleshooting guide.
The electrical and electronic components are identified by circuit identification numbers on
the schematics and the parts list. The test
designations shown in the schematics.
.
The procedures described in this manual require advanced technical experience
CAUTION: To reduce the risk of electric shock,
do not remove the cover. No user-serviceable
parts inside. Refer servicing to qualified
personnel.
WARNING: To prevent fire or electric shock, do
not expose this equipment to rain or moisture.
&
troubleshooting sections refer to
CAUTION
Equivalent Parts
Although many of the electronic components used in this product may be available from
WC.
electronic suppliers, some components are specially tested and approved by
product repaired with
Repairs performed using non-QSC parts may void the product warranty.
you may contact
Parts orders to QSC should include the product model number, the part description, and
the QSC part number (from the parts list in this manual). Parts will be shipped via UPS,
F.O.B. Costa Mesa, California. Shipping, handling and COD charges may be added to
the cost of the parts.
non-WC
QSC
Technical Services for assistance.
supplied components may not meet factory specifications.
men
A
in doubt,
Factory Repair
It may become necessary to return a product to the factory for repair. Call QSC Technical
Services for return instructions. QSC Technical Services may be reached at (800)
772-2834.
Test and Troubleshooting Equipment
-Audio
-
Distortion Analyzer capable of 0.01% THD+N
-
High Power Load Bank
-
Function Generator 8 Digital Multimeter
-
2OMHz
Oscilloscope
-
Variac (0-140
VAC, 30-40A)
(8,4,8
2
ohms)
Precision - System One
+
Thermometer
2
Page 7
Test & Calibration
PLX 1202 Test Procedure
.
SET-UP
1.
Connect a test load to the output terminals of the amplifier.
-
2. Make sure Mode Switches 1
3. Connect a distortion analyzer with a resolution of
output terminals of the amplifier. Enable the
4. Connect a dual-channel oscilloscope to the following test points:
Chl
-
a
IOX
(vertical sensitivity -
Ch2
-
a IX scope probe (vertical sensitivity -
output.
5.
Set amp gain pots fully clockwise and turn on power switch.
6. Connect the output of the signal generator to the input terminals of the amplifier and
select an output of 1.30
7. Plug the amplifier into a variac and set up an AC line current monitor.
. POWER UP 8 MUTE DELAY TEST
CAUTION: To avoid damage to the main printed circuit board, place a 50 ohm
240VAC) in series with the high
supply has a shorted device at initial power up, this AC resistor pad will help prevent undue damage. After
the amplifier has been fully powered up via the variac, confirm that the amplifier has achieved
stable operation during idle. Remove AC power from the amplifier and disconnect the series
resistor for normal operation. Continue with the test
10 are in the default position (1 on, 10 on, all others off).
O.Ol%, 20-2OkHz
8OkHz
low pass filter.
2V/cm)
scope probe to the channel speaker output.
O.lV/cm)
VRMS,
1
kHz
sine wave.
(+)
lead on the AC cable during variac ramp up. If the switching power
&
calibration process.
to the distortion analyzer
(or better) to the
225W
resistor (100 ohm,
I. Slowly raise the variac voltage and watch for excessive current draw (line current
greater than
0.5A
a.c. at 60 Volts). This is slightly less for 240V.
Pause at
(2OOVAC European) for three seconds until the mute I protect circuit disengages.
Continue to
12OVAC
(240V European).
2. Verify that the fan is operating at low speed.
3. Turn the power switch off and on a few times to verify the 3 second power-up muting
delay.
l CHANNEL OUTPUT
I. Look for amplified signal on the scope for channel 1. Switch the input signal and scope
/
to channel 2 and repeat output test. Check for noisy
contaminated gain pots by
observing general instability on the distortion waveform while adjusting the gain control
levels.
2. Select an 8 ohm load and confirm that this amplifier is producing 200 watts at 1 kHz just
below the point of clipping. Check both channels.
l BRIDGE MODE
1. Turn the power switch off.
#7
2. Set Mode Switch
on CH2 are disabled with Mode Switch
3.
Set load to both red output binding posts
4. Apply a 1.30
in the on position. The gain control, limiter, and filter switch positions
#7
on.
(CHI
positive and CH2 negative).
VRMS,
1
kHz
sinewave input to channel I of the amplifier. Check the power
and verify that the output does not immediately collapse. Check for 700 watts at 8 ohms.
9OVAC
Page 8
5.
Turn power off and place the amplifier back into the Stereo mode with output
loads connected to each channel.
. BIAS
1. Let the amplifier cool down to room temperature.
2. With an input amplitude of
1.3OVrms
input signal 20dB (80%) from full output. Adjust the crossover
VR166 (CH2) for about a
4OOmVpk-pk
increase the input frequency to
trimpot
2OkHz.
VR43
crossover spike protruding from the noise trace
on the oscilloscope. It will be necessary to have the oscilloscope measure unfiltered
distortion from the amplifier in order to see the crossover spike. It is necessary to
disable the 80kHz
lowpass
filter on the analyzer for this test.
Further trim so that
the total distortion for that channel is less than 0.1% THD+N.
3. With the trim settings achieved, and with no signal plugged into the amplifier and with an
8 ohm load, verify that the AC idle current from the AC service is no more than 1 .O
amperes.
4. Let the amplifier cool down and check channel 2.
. SHORT CIRCUIT CURRENT
1.
Select a 2 ohm load and apply a
of the amplifier.
Ensure that power is on and that the gain controls are fully up.
1.3Vrms
sinewave (1
kHz)
input signal to both channels
2. While the amplifier is producing power into the loads, apply a short to the output binding
posts of each channel. In other words, apply a jumper between the red and black
binding posts of each channel. Once this is done, combined AC line current draw for
both channels should be no greater than
13A ac.
This is with a 120 volt AC service to
the amplifier. Current may be lower if AC line voltage is lower.
3. Remove the short from each channel and verify that the channels recover in to 2 ohm
loads. The output should not experience any hang up and a full
sinewave
should be
present just as it was before a short was applied for this test.
4. If the amplifier does not pass any of the above steps, troubleshoot the current limit
section of the amplifier. If steps 2, 3, and 4 above pass, continue to the next test
FREQUENCY RESPONSE.
Reduce the
(CHl)
and
l FREQUENCY RESPONSE
1,
Set load to 8 ohms and scale the input generator to gain 1 watt of power from the
amplifier on each channel. Gain controls on the amplifier should be fully up.
2.
Check frequency response from
2OHz
to 20kHz
(+I- 0.2OdB)
by sweeping random
frequencies between these extremes. This is done by verifying the same voltage
amplitude at each of the frequencies selected (within
2OHz
to
2OkHz).
Check both
channels.
l POWER vs. DISTORTION TEST
I. Check to ensure that both channels will produce rated power at
2OHz, 2KHz,
into an 8 ohm load.
2. While verifying rated power, check that at all frequencies the distortion measurement is
less than or equal to 0.03% THD.
l THERMAL TEST
1. Set input frequency to 1 KHz and short both channels while they are producing power into
a load.
2. Apply a short to the output of each channel.
3. AC line current draw should be about 11 - 13.5 amperes for both channels. As the
amplifier gets hot, there will be some current drift upwards and the fan speed will
increase. This is not a problem as long as the case temperature on the output
transistors does not exceed
105
degrees C.
and 20kHz.
4
Page 9
4.
Verify that the NTC circuit causes thermal shutdown after an extended period.
5. When thermal shutdown occurs, verify AC idle current of less that 0.90 amperes
l CM TEST
1. Select an 8 ohm load and confirm that this amplifier is producing rated power.
2. Check the Common Mode of the amplifier by inserting a
channel and observe about 6
dB
of output voltage reduction. There will also be a 180
1/4”
input jack halfway into each
degree phase inversion at the output of the channel under test.
l OUTPUT NOISE
1. Set the amplifier gain controls all the way up, with a 1
kHz 1.3OVrms sinewave
signal. Note the output level at full power just below clipping. Adjust gain if needed.
2. Remove the input signal connector from the amplifier and measure the residual noise
level produced into the load by the amplifier. The noise signal should be 107
from the full output power point measured. A signal to noise ratio should be better than
or equal to
l FINAL CHECK
107dB.
Check both channels.
This completes the amplifier test procedure for this model.Inspect the amplifier for
mechanical defects. Inspect the solder connections. Reassemble the amplifier and verify
the amplifier’s operation before returning the product to service.
input
dB
down
PLX 1602 Test Procedure
.
SET-UP
1.
Connect a test load to the output terminals of the amplifier.
2.
Make sure Mode Switches 1
Connect a distortion analyzer with a resolution of
3.
output terminals of the amplifier.Enable the 80kHz low pass filter.
4.
Connect a dual-channel oscilloscope to the following test points:
Chl -
a 1 OX (vertical sensitivity -
Ch2
-
a IX scope probe (vertical sensitivity -
output.
5.
Set amp gain pots fully clockwise and turn on power switch.
Connect the output of the signal generator to the input terminals of the amplifier and
6.
select an output of 1.30
Plug the amplifier into a variac and set up an AC line current monitor.
7.
l POWER UP 8 MUTE DELAY TEST
CAUTION: To avoid damage to the main printed circuit board, place a 50 ohm 225W resistor (100 ohm,
240VAC) in series with the high
supply has a shorted device at initial power up, this AC resistor pad will help prevent undue damage. After
the amplifier has been fully powered up via the variac, confirm that the amplifier has achieved
stable operation during idle. Remove AC power from the amplifier and disconnect the series
resistor for normal operation. Continue with the test
Slowly raise the variac voltage and watch for excessive current draw (line current
greater than
(2OOVAC
European) for three seconds until the mute I protect circuit disengages.
Continue to
0.5A a.c
12OVAC (24OV
at 60 Volts).
Verify that the fan is operating at low speed.
-
10 are in the default position (1 on, 10 on, all others off)
VRMS,
1
(+)
lead on the AC cable during variac ramp up. If the switching power
European).
O.Ol%, 20-20kHz
2V/cm)
scope probe to the channel speaker output.
O.lV/cm)
kHz
sine wave.
&
calibration process.
T/I;s is s/;ghf/y less
to the distortion analyzer
for 240V. Pause at
(or better) to the
9OVAC
Page 10
3. Turn the power switch off and on a few times to verify the 3 second power-up muting
delay.
. CHANNEL OUTPUT
1. Look for amplified signal on the scope for channel 1. Switch the input signal and scope
to channel 2 and repeat output test. Check for noisy
/
contaminated gain pots by
observing general instability on the distortion waveform while adjusting the gain control
levels.
2. Select an 8 ohm load and confirm that this amplifier is producing 300 watts at 1 kHz just
below the point of clipping. Check both channels.
. BRIDGE MODE
1. Turn the power switch off.
2. Set Mode Switch
on CH2 are disabled with Mode Switch
3. Set load to both red output binding posts
4. Apply a 1.30
#7
in the on position. The gain control, limiter, and filter switch positions
#7
on.
(CHI
positive and CH2 negative).
VRMS,
1
kHz
sinewave input to channel 1 of the amplifier. Check the power
and verify that the output does not immediately collapse. Check for 1000 watts at 8
ohms.
5.
Turn power off and place the amplifier under test back into the Stereo mode with output
loads connected to each channel.
l BIAS
I. Let the amplifier cool down to room temperature.
2. With an input amplitude of
input signal 20dB (80%) from full output. Adjust the crossover
VR166 (CH2) for about a
1.3OVrms
increase the input frequency to 20kHz. Reduce the
4OOmVpk-pk
trimpot
VR43
crossover spike protruding from the noise trace
on the oscilloscope. It will be necessary to have the oscilloscope measure unfiltered
distortion from the amplifier in order to see the crossover spike.
disable the 80kHz
lowpass
filter on the analyzer for this test. Further trim so that
It is necessary to
the total distortion for that channel is less than 0.1% THD+N.
3. With the trim settings achieved, and with no signal plugged into the amplifier and with an
8 ohm load, verify that the AC idle current from the AC service is no more than 1 .O
amperes.
4. Let the amplifier cool down and check channel 2.
(CHl)
and
l SHORT CIRCUIT CURRENT
1.
Select a 2 ohm load and apply a
of the amplifier.Ensure that power is on and that the gain controls are fully up.
2. While the amplifier is producing power into the loads, apply a short to the output binding
posts of each channel.
binding posts of each channel. Once this is done, combined AC line current draw for
both channels should be no greater than
the amplifier. Current may be lower if AC line voltage is lower.
3. Remove the short from each channel and verify that the channels recover in to 2 ohm
loads. The output should not experience any hang up and a full
present just as it was before a short was applied for this test.
4. If the amplifier does not pass any of the above steps, troubleshoot the current limit
section of the amplifier. If steps 2, 3, and 4 above pass, continue to the next test
FREQUENCY RESPONSE.
6
1.3Vrms
sinewave (1
kHz)
input signal to both channels
In other words, apply a jumper between the red and black
13A
ac. This is with a 120 volt AC service to
sinewave
should be
Page 11
l FREQUENCY RESPONSE
I.
Set load to 8 ohms and scale the input generator to gain 1 watt of power from the
amplifier on each channel. Gain controls on the amplifier should be fully up.
2. Check frequency response from
2OHz
to 20kHz
(+I- 0.2OdB)
by sweeping random
frequencies between these extremes. This is done by verifying the same voltage
2OHz
amplitude at each of the frequencies selected (within
to 20kHz). Check both
channels.
l POWER vs. DISTORTION TEST
1. Check to ensure that both channels will produce rated power at
2OHz, 2KHz,
into an 8 ohm load.
2.
While verifying rated power, check that at all frequencies the distortion measurement is
less than or equal to 0.03% THD.
l THERMAL TEST
1.
Set input frequency to 1 KHz and short both channels while they are producing power into
a load.
2. Apply a short to the output of each channel.
3. AC line current draw should be about
II -
13.5 amperes for both channels. As the
amplifier gets hot, there will be some current drift upwards and the fan speed will
increase. This is not a problem as long as the case temperature on the output
transistors does not exceed 105 degrees
C.
4. Verify that the NTC circuit causes thermal shutdown after an extended period.
5. When thermal shutdown occurs, verify AC idle current of less that 0.90 amperes.
and 20kHz.
l CM TEST
1. Select an 8 ohm load and confirm that this amplifier is producing rated power.
2. Check the Common Mode of the amplifier by inserting a
dB
channel and observe about 6
of output voltage reduction. There will also be a 180
1/4”
input jack halfway into each
degree phase inversion at the output of the channel under test.
l OUTPUT NOISE
I. Set the amplifier gain controls all the way up, with a 1
signal.
Note the output level at full power just below clipping. Adjust gain if needed.
kHz 1.3OVrms sinewave
2. Remove the input signal connector from the amplifier and measure the residual noise
level produced into the load by the amplifier. The noise signal should be 107
from the full output power point measured. A signal to noise ratio should be better than
107dB.
or equal to
l FINAL CHECK
This completes the amplifier test procedure for this model.
Check both channels.
Inspect the amplifier for
mechanical defects. inspect the solder connections. Reassemble the amplifier and
the amplifier’s operation before returning the product to service.
PLX 2402 Test Procedure
l SET-UP
1. Connect a test load to the output terminals of the amplifier.
2. Make sure Mode Switches 1
- 10
are in the default position (1 on, 10 on, all others off).
input
dB
down
veri@
Page 12
3. Connect a distortion analyzer with a resolution of
O.Ol%, 20-20kHz
(or better) to the
output terminals of the amplifier. Enable the 80kHz low pass filter.
4. Connect a dual-channel oscilloscope to the following test points:
Chl
-
a
1OX
(vertical sensitivity - 2V/cm) scope probe to the channel speaker output.
Ch2
-
a IX scope probe (vertical sensitivity - 0.
IV/cm)
to the distortion analyzer
output.
5. Set amp gain pots fully clockwise and turn on power switch.
6. Connect the output of the signal generator to the input terminals of the amplifier and
select an output of 1.50
VRMS
1
kHz
sine wave.
7. Plug the amplifier into a variac and set up an AC line current monitor.
l POWER UP
&
MUTE DELAY TEST
CAUTION: To avoid damage to the main printed circuit board, place a 50 ohm
240VAC) in series with the high
supply has a shorted device at initial power up, this AC resistor pad will help prevent undue damage. After
the amplifier has been fully powered up via the variac, confirm that the amplifier has achieved
stable operation during idle. Remove AC power from the amplifier and disconnect the series
resistor for normal operation. Continue with the test
(+)
lead on the AC cable during variac ramp up. if the switching power
&
calibration process.
225W
resistor (100 ohm,
1. Slowly raise the variac voltage and watch for excessive current draw (line current
greater than
(2OOVAC
European) for three seconds until the mute / protect circuit disengages.
Continue to
0.5A a.c
at 60 Volts).
12OVAC (24OV
This
European).
is
slight/y /ess fof
24OV.
Pause at
2. Verify that the fan is operating at low speed.
3.
Turn the power switch off and on a few times to verify the 3 second power-up muting
delay.
l CHANNEL OUTPUT
I. Look for amplified signal on the scope for channel
to channel 2 and repeat output test. Check for noisy
1.
Switch the input signal and scope
/
contaminated gain pots by
observing general instability on the distortion waveform while adjusting the gain control
levels.
2. Select an 8 ohm load and confirm that this amplifier is producing 425 watts at 1 kHz just
below the point of clipping. Check both channels.
l BRIDGE MODE
1. Turn the power switch off.
2. Set Mode Switch
on CH2 are disabled with Mode Switch
3. Set load to both red output binding posts
4. Apply a 1.30
#7
in the on position. The gain control, limiter, and filter switch positions
#7
on.
(CHI
positive and CH2 negative).
VRMS,
1
kHz sinewave
input to channel 1 of the amplifier. Check the power
and verify that the output does not immediately collapse. Check for 1500 watts at 8
ohms.
5. Turn power off and place the amplifier under test back into the Stereo mode with output
loads connected to each channel.
l BIAS
1.
Let the amplifier cool down to room temperature.
2. With an input amplitude of
input signal 20dB (80%) from full output. Adjust the crossover
VR166 (CH2) for about a
1.5OVrms,
increase the input frequency to
4OOmVpk-pk
2OkHz.
trimpot
VR43
crossover spike protruding from the noise trace
on the oscilloscope. It will be necessary to have the oscilloscope measure unfiltered
distortion from the amplifier in order to see the crossover spike.
It is necessary to
9OVAC
Reduce the
(CHl)
and
Page 13
disable the 80kHz
the total distortion for that channel is less than 0.1%
lowpass
filter on the analyzer for this test.Further trim so that
THD+N,
3. With the trim settings achieved, and with no signal plugged into the amplifier and with an
8 ohm load, verify that the AC idle current from the AC service is no more than 1 .O
amperes.
4. Let the amplifier cool down and check channel
l SHORT CIRCUIT CURRENT
1.
Select a 2 ohm load and apply a
1.3Vrms
2.
sinewave (1
kHz)
input signal to both channels
of the amplifier.Ensure that power is on and that the gain controls are fully up.
2. While the amplifier is producing power into the loads, apply a short to the output binding
posts of each channel. In other words, apply a jumper between the red and black
binding posts of each channel. Once this is done, combined AC line current draw for
both channels should be no greater than
13A
ac. This is with a 120 volt AC service to
the amplifier. Current may be lower if AC line voltage is lower.
3. Remove the short from each channel and verify that the channels recover in to 2 ohm
loads. The output should not experience any hang up and a full
sinewave
should be
present just as it was before a short was applied for this test,
4. If the amplifier does not pass any of the above steps, troubleshoot the current limit
section of the amplifier. If steps 2, 3, and 4 above pass, continue to the next test
FREQUENCY RESPONSE.
l FREQUENCY RESPONSE
1. Set load to 8 ohms and scale the input generator to gain 1 watt of power from the
amplifier on each channel. Gain controls on the amplifier should be fully up.
2. Check frequency response from
2OHz
to 20kHz
(+/- 0.2OdB)
by sweeping random
frequencies between these extremes. This is done by verifying the same voltage
amplitude at each of the frequencies selected (within
2OHz
to 20kHz). Check both
channels.
l POWER vs. DISTORTION TEST
1. Check to ensure that both channels will produce rated power at
2OHz, 2KHz,
into an 8 ohm load.
2. While verifying rated power, check that at all frequencies the distortion measurement is
less than or equal to 0.03%
l THERMAL TEST
THD.
1. Set input frequency to 1 KHz and short both channels while they are producing power into
a load.
2. Apply a short to the output of each channel.
11
-
3. AC line current draw should be about
13.5 amperes for both channels. As the
amplifier gets hot, there will be some current drift upwards and the fan speed will
increase, This is not a problem as long as the case temperature on the output
transistors does not exceed 105 degrees C.
4. Verify that the NTC circuit causes thermal shutdown after an extended period.
5,
When thermal shutdown occurs, verify AC idle current of less that 0.90 amperes.
l CM TEST
I. Select an 8 ohm load and confirm that this amplifier is producing rated power.
2. Check the Common Mode of the amplifier by inserting a
114”
input jack halfway into each
channel and observe about 6 dB of output voltage reduction. There will also be a 180
degree phase inversion at the output of the channel under test.
and 20kHz.
9
Page 14
l OUTPUT NOISE
1. Set the amplifier gain controls all the way up, with a I
signal.
Note the output level at full power just below clipping. Adjust gain if needed.
kHz 1.5OVrms sinewave
2. Remove the input signal connector from the amplifier and measure the residual noise
level produced into the load by the amplifier. The noise signal should be 107
from the full output power point measured. A signal to noise ratio should be better than
or equal to
l FINAL CHECK
107dB.
Check both channels.
This completes the amplifier test procedure for this model.Inspect the amplifier for
mechanical defects. Inspect the solder connections. Reassemble the amplifier and verify
the amplifier’s operation before returning the product to service,
PLX 3002 Test Procedure
l SET-UP
1. Connect a test load to the output terminals of the amplifier.
2. Make sure Mode Switches 1 - 10 are in the default position (1 on, 10 on, all others off).
3.
Connect a distortion analyzer with a resolution of
output terminals of the amplifier. Enable the 80kHz low pass filter.
4. Connect a dual-channel oscilloscope to the following test points:
-
a
1OX
Chl
Ch2
(vertical sensitivity -
-
a 1X scope probe (vertical sensitivity -
2V/cm)
scope probe to the channel speaker output.
output.
5.
Set amp gain pots fully clockwise and turn on power switch.
6. Connect the output of the signal generator to the input terminals of the amplifier and
select an output of 1.70
VRMS,
1
kHz
sine wave.
7. Plug the amplifier into a variac and set up an AC line current monitor.
O.Ol%,
O.lV/cm)
20-20kHz
(or better) to the
to the distortion analyzer
input
dB
down
. POWER UP 8 MUTE DELAY TEST
CAUTION: To avoid damage to the main printed circuit board, place a 50 ohm 225W resistor (100 ohm,
240VAC) in series with the high
supply has a shorted device at initial power up, this AC resistor pad will help prevent undue damage. After
the amplifier has been fully powered up via the variac, confirm that the amplifier has achieved
stable operation during idle. Remove AC power from the amplifier and disconnect the series
resistor for normal operation. Continue with the test
1.
Slowly raise the variac voltage and watch for excessive current draw (line current
greater than
(2UOVAC
Continue to
0.5A
a.c. at 60 Volts).
European) for three seconds until the mute / protect circuit disengages.
12OVAC
(+)
lead on the AC cable during variac ramp up. If the switching power
TIG.s is s/ight/y
(240V European).,
&
calibration process.
less for
24UV.
Pause at
2. Verify that the fan is operating at low speed.
3. Turn the power switch off and on a few times to verify the 3 second power-up muting
delay.
l CHANNEL OUTPUT
1.
Look for amplified signal on the scope for channel 1. Switch the input signal and scope
to channel 2 and repeat output test. Check for noisy I contaminated gain pots by
observing general instability on the distortion waveform while adjusting the gain control
levels.
9OVAC
10
Page 15
2. Select an 8 ohm load and confirm that this amplifier is producing
550
watts at 1 kHz just
below the point of clipping. Check both channels.
l BRIDGE MODE
1. Turn the power switch off.
2. Set Mode Switch
on CH2 are disabled with Mode Switch
3. Set load to both red output binding posts
4. Apply a 1.30
#7
in the on position. The gain control, limiter, and filter switch positions
#
7 on.
(CHI
positive and CH2 negative).
VRMS,
1
kHz
sinewave input to channel 1 of the amplifier. Check the power
and verify that the output does not immediately collapse. Check for 2000 watts at 8
ohms.
5. Turn power off and place the amplifier under test back into the Stereo mode with output
loads connected to each channel.
l BIAS
1.
Let the amplifier cool down to room temperature.
2. With an input amplitude of
input signal 20dB
VRl66
(CH2) for about a
(80°h)
1.7OVrms
increase the input frequency to 20kHz. Reduce the
from full output. Adjust the crossover
4OOmVpk-pk
crossover spike protruding from the noise trace
trimpot
VR43
on the oscilloscope. It will be necessary to have the oscilloscope measure unfiltered
distortion from the amplifier in order to see the crossover spike. It is necessary to
disable the 80kHz
lowpass
filter on the analyzer for this test.Further trim so that
the total distortion for that channel is less than 0.1% THD+N.
3,
With the trim settings achieved, and with no signal plugged into the amplifier and with an
8 ohm load, verify that the AC idle current from the AC service is no more than 1 .O
amperes.
4. Let the amplifier cool down and check channel
2.
(CHI)
and
l SHORT CIRCUIT CURRENT
1.
Select a 2 ohm load and apply a
1.3Vrms
sinewave (1
kHz)
input signal to both channels
of the amplifier.Ensure that power is on and that the gain controls are fully up.
2,
While the amplifier is producing power into the loads, apply a short to the output binding
posts of each channel. In other words, apply a jumper between the red and black
binding posts of each channel. Once this is done, combined AC line current draw for
both channels should be no greater than
13A
ac. This is with a 120 volt AC service to
the amplifier. Current may be lower if AC line voltage is lower.
3. Remove the short from each channel and verify that the channels recover in to 2 ohm
loads. The output should not experience any hang up and a full
sinewave
present just as it was before a short was applied for this test.
4. If the amplifier does not pass any of the above steps, troubleshoot the current limit
section of the amplifier. If steps 2, 3, and 4 above pass, continue to the next test
FREQUENCY RESPONSE.
l FREQUENCY RESPONSE
1. Set load to 8 ohms and scale the input generator to gain I watt of power from the
amplifier on each channel. Gain controlson the amplifier should be fully up.
2. Check frequency response from
to 20kHz
(+I- 0.2OdB)
by sweeping random
2OHz
frequencies between these extremes. This is done by verifying the same voltage
amplitude at each of the frequencies selected (within
2OHz
to 20kHz). Check both
channels.
should be
11
Page 16
l POWER vs. DISTORTION TEST
1.
Check to ensure that both channels will produce rated power at
2OH2, 2KHz,
into an 8 ohm load.
2. While verifying rated power, check that at all frequencies the distortion measurement is
less than or equal to 0.03% THD.
l THERMAL TEST
I. Set input frequency to
1 KHz and short both channels while they are producing power into
a load.
2. Apply a short to the output of each channel.
3. AC line current draw should be about 11
-
13.5 amperes for both channels. As the
amplifier gets hot, there will be some current drift upwards and the fan speed will
increase. This is not a problem as long as the case temperature on the output
transistors does not exceed 105 degrees
C.
4. Verify that the NTC circuit causes thermal shutdown after an extended period.
5. When thermal shutdown occurs, verify AC idle current of less that 0.90 amperes.
l CM TEST
1. Select an 8 ohm load and confirm that this amplifier is producing rated power.
2. Check the Common Mode of the amplifier by inserting a
channel and observe about 6 dB of output voltage reduction. There
114”
input jack halfway into each
will
also be a 180
degree phase inversion at the output of the channel under test.
l OUTPUT NOISE
1. Set the amplifier gain controls all the way up, with a 1
signal.
Note the output level at full power just below clipping. Adjust gain if needed.
kHz 1.7OVrms sinewave
2. Remove the input signal connector from the amplifier and measure the residual noise
level produced into the load by the amplifier. The noise signal should be 107
from the full output power point measured. A signal to noise ratio should be better than
or equal to
107dB.
Check both channels.
and 20kHz.
input
dB
down
l FINAL CHECK
This completes the amplifier test procedure for this model.
Inspect the amplifier for
mechanical defects. Inspect the solder connections. Reassemble the amplifier and verify
the amplifier’s operation before returning the product to service.
12
Page 17
T r o ubleshooting
PLX 1202 l PLX 1602 l PLX 2402 l PLX 3002
Power Supply -
In order to improve
are driven by an active, direct coupled integrated circuit, rather than a gate drive transformer.
driver failure should be rare (when correctly assembled) but when the
following parts:
CHECKLIST AFTER BLOWN
Q96, Q97,
D78, D79,
Ul8, lR2110
also typically damage the gate coupling parts noted above.
Ul9,
SOMETIMES
RARELY
PROBABLE CAUSES OF MASSIVE
SHORTS IN CONTROL CIRCUIT.
The parts operate well within their ratings and should hold up well in the field. The usual cause of failure is
when both
signal to one part to remain on when the other part is supposed to turn on. Shorts from solder or debris are
one obvious cause.
SHORTS IN THE LOAD.
Although there is peak current shutdown, shorts in the power amplifier transistors or secondary-side supply
components can cause currents to increase too quickly to prevent damage.
(IGBT’s
R358, R359,
high-side gate driver, Fault current when low-side
3525 controller, Blows from currents shorted
Ul3,
IGBT’s
EMI
performance, reduce cost, and increase current capacity, the PLX
generally fail in pairs)
gate drive coupling
Ul4, 556,
which has fairly high supply voltage ratings.
powered from 5V output of 3525, which may fail high when 3525 fails.
turn on at once, shorting Pri-Hi to Pri-Lo. This occurs when something causes the drive
Replacing Blown
-
IGBT’S
IGBT
comonents,
FAULTS
check after removing blown
thru Ul8,
IGBTs.
IGBTs
IGBT
or
IGBT’s
blow, it usually damages the
IGBT’s.
IGBT
shorts to upper rail. Such currents
or possibly by overvoltage on the supply rail
OVERVOLTAGE ON THE BIAS SUPPLY.
If the TOP-210 bias supply fails to operate, no harm occurs, the unit simply does not operate.
However, open circuit (missing part) in several key components can cause the Bias supply voltage to be
much too high, This blows the 2110 and thus the
QUICK TEST OF BIAS SUPPLY.
Ramp the AC voltage up slowly to 25% of regular voltage (30V for
normally, the green “power” LED should come on between 30 and
start-up level. If the LED comes on at
until you have measured the bias voltage. The switching will not start until you reach
the
IGBT’s
from blowing.
Confirm that bias voltage at Cl38 is
feedback to U16 and cause overvoltage.
2OV,
18-19V.
IGBT’s.
or not until
Open or missing
5OV,
12OV
unit). If the bias supply is working
35Vz
with its usual, steady
or blinks, DO NOT RAISE VOLTAGE PAST 60V
9OV,
D63,
64, 65, 66, 67 or R349 will break the
“half-brighr
so you can save
13
Page 18
Troubleshooting “TOP-210” Bias Supply.
QUICK TEST OF BIAS SUPPLY.
Ramp the AC voltage up slowly to 25% of regular voltage (30V for
normally, the green “power” LED should come on between 30 and
start-up level.
CAUTION: if the LED comes on at
until you have measured the bias voltage. The switching will not start until you reach
the
IGBT’s
from blowing.
Confirm that bias voltage at Cl38 is
BIAS SUPPLY VOLTAGE MUCH TOO HIGH
D63,64,65,66,67
NO BIAS SUPPLY VOLTAGE
U16 missing or blown.
Tl missing, reversed, or open primary
D62 open or missing.
BIAS VOLTAGE ERRORS
The exact voltage is controlled by the feedback through
Cl38 is the
D63,
Cl39 , is the
D66,
R349 subtracts about
Ul6
uses this feedback to adjust the “on” time at pin 5, in order
charging Cl38 and thus maintain regulation of the
C142,
“hunting”.
Q99
and associated R374 reduce the voltage of the Bias supply by 33% when the AC voltage is turned off.
This prevents the Power LED from showing at half brightness after turn-off, since U16 continues to run
from the main filters for some time after shut down R375 and 376 sense the output of
AC” comparator, and cause
AC is turned on.
“+18V’
64, 65 each subtract a diode drop
a
IOV zener
R356,
or R349 open or missing -- breaks feedback to U16
rail with about
“+16V”
rail with about
diode , plus diode
0.5V,
bringing the net voltage at
and R349 form a closed-loop stability circuit which prevents the regulated voltage from
18.8V
Q99
to turn on. If
2OV,
or not until
18-19V.
typical.
(0.7V)
16.6V typcial.
D67,
subtract about 1 IV from
5OV,
from Cl38.
+16V
Q99
is shorted, the bias voltages will remain 33% low when
or blinks, DO NOT RAISE VOLTAGE PAST 60V
D63, 64_
Ul6,
feedback pin 4, to about
and
12OV
unit). If the bias supply is working
35V,
with its usual, steady
9OV,
65, 66, 67 and R349 as follows:
+16.6V.
5.lV.
toraise
+18V
or lower the
supplies
flyback
Ul3:3,
“half-brighf’
so you can save
voltage
the “Loss of
14
REPLACING BLOWN TOP-210.
If U16 has blown, check T-l for continuity after removing
measure about 15 ohms
Ul6.
Its primary may be open. Pins I-2 It should
Replacing Blown Output Transistors
OUTPUT TRANSISTOR SHORTED
Stmrk
in one device tend to cause the opposing device to blow as
If an output transistor shorts:
Drive transistor will be shorted
CXNne
transistors will short in pairs (Q39 &
The rest will short in fours
IGBT’s
8 their associated components may
(Q26, Q27, Q71,
(Q28, Q29,
Q34 &
Q72)
Q40,
Q36 &
Q35; Q73, Q74, Q79 8, Q80)
fail
well,
Q37, Q84
8
Q85, Q81 8, Q82)
Page 19
CHECK EMITTER AND BASE RESISTORS WHILE DEVICES ARE REMOVED,
Each output transistor has an associatated pair of 0.47 ohm resistors in parallel.
Each BANK of output transistors has a 15 ohm resistor from base to rail (emitter bus).
Audio Outputs, Troubleshooting Current Limit
WEAK CURRENT LIMIT -- PREMATURE CLIPPING.
The usual symptom of weak output current is premature clipping of one or more peaks of the audio voltage.
This could be caused by missing step, weak current limit, or dead output section.
PREMATURE CLIPPING at 60% VOLTAGE, SIMILAR AT ALL IMPEDANCES:
This points to a step problem (2402, 3002 only). See Step Troubleshooting.
If the amplifier reaches full voltage at 8 ohms, but prematurely clips at 4 ohms or 2 ohms, we can assume
the step is OK but the output current is too low (see below).
NO OUTPUT AT ALL ON ONE POLARITY.
This indicates complete failure (open circuit) in the circuit leading to the dead output polarity. Check the
series components in the current splitter for missing or open:
Ch 1:
Ch 2:
CONSTANT, PREMATURE CLIPPING, WORSE AT LOW IMPEDANCES.
First, check the clamping voltages on
table below. At idle, all four voltages should all be similar. If one is out, check parts according to the
following table
Positive,
Positive,
Ql9, R381, Q20, R70, DIO,
Q64, R383, Q65, Rl93, D35,
C21
(Ch
D14. Negative:
D39. Negative:
I+),
C22 (Ch I-),
Q22, R382, Q21, R71,
Q67, R384, Q66, Rl94, D36,
C56
(Ch
2+), C57
(Ch
Dl I, D12
2-),
as shown in
D37
CLAMPING VOLTAGES ARE WRONG AT IDLE
I+
CHANNEL-POLARITY
Measure voltage on:
3002 and 2402, about
1602, about
1202 about
Voltage too high: missing resistor:
Voltage
Voltage
Voltage wrong: wrong value
The exact voltage varies with temperature. Look for the mismatching value on the weak cell.
A too-low voltage causes early clamping of that output section, as explained in the previous several pages.
If the voltage is correct and current is still low, also check for missing - unsoldered output device, or emitter
resistors.
4,6V,
4.9V.
or missing transistor:
0-0.3V:
or missing resistor
0.7V,
missing resistor:
6V.
shorted transistor
CH
c21
R60
Q14
Ql4,24
R
51,
72
R59
R59,60
CH
l-
c22
R61
Ql5
Ql5,
25
R53,
75
R62
R62,61
2+
CH
C56
RI83
Q59
Q59,69
Rl74,
RI82
Rl82,
195
183
2-
CH
c57
RI84
Q60
Q60,70
Rl76,
198
RI85
Rl85,184
15
Page 20
Audio Power Stage, Current Limit Troubleshooting
CURRENT LIMITS WHICH COLLAPSE PREMATURELY.
An immediate collapse of ALL current limits at full power could be premature triggering of “Power Supply
Cutback”, which is described in the section below. Cutback after several seconds of full power operation at
two ohms is normal.
Cutback of one or more output sections, at full temperature, while approaching full power into two ohms is
also normal. However, cutbacks at 4 ohms, or when cold into two ohms, indicate problems with the
transistor power measuring circuitry.
CLAMPING VOLTAGES COLLAPSE TOO SOON.
CH
CHANNEL-POLARITY
Measure voltage on:
Cuts back too easily: low value,
or high value: R 51,
or missing diode:
CLAMPING VOLTAGES ARE CORRECT, CURRENT STILL WEAK.
Shorted diode
Missing-unsoldered output device or emitter resistor.
TROUBLESHOOTING “POWER SUPPLY CUTBACK”.
As noted in the section on Power Supply, the amplifier’s current limit cuts back when necessary to protect
the power supply. Because the Observed effect is a reduced output voltage, in response to prolonged
operation above the long-term current limit, we commonly refer to this behavior as “power supply cutback”,
but we must remember that it is actually
from the power supply. Full power operation into 2 ohms (both channels) should produce a 50% cutback of
current after several seconds.
If both channels of the amplifier fail to cut back after about 3 seconds, 2-ohms, both channels driven, the
cutback signal is probably missing. CAUTION: Prolonged operation under these conditions could blow
IGBT
or burn out
Check the output (secondary side) pins of U17 (sh 4). Confirm presence of
normally be at about
If
Ul7-pin
4 does not go high, check U17 itself. If it appears OK, trace the circuitry driving U17 (PRIMARY
SIDE, CAUTION). Check for continuity through
R347,
all of which drive optocoupler U17. A short in R346 or Cl31 will also prevent drive to U17.
If
Ul7-pin
4 goes high on schedule, and BOTH channels fail to cut back, trace voltage on
R273 (sh
(sh 2). If only ONE channel fails to cut back, look for missing
(sh 2).
Cl31 controls the speed of cutback.. If missing, the amplifier current limits will enter cutback almost
immediately at or above full power, 4 ohms.
Cl44.
Test for 6-10 seconds maximum.
OV,
and go high (I-5V) after 3 seconds at full power,
3),
which connects to “MUTE+” bus. Continue tracing voltage on MUTE+ to
I+
c21
R67,
73
72
D9
DIO, 14
amp/Tier
CH
l-
c22
R68,
74
R53,
75
D8
Dll,
12
current
L6:2
hmifhg
in response to an overload signal sent
to Pri-Lo, check missing or open
Ql6,
CH
2+
C56
Rl90,
Rl74,
D34
D35,
39
+6V
R 65,
Ql7
CH
2-
c57
196
195
on pin 5. Pin 4 should
(sh I) or
Rl91,
197
Rl76,
198
D33
D36,
37
R343, D61, Q95,
“PS_OL”
Ql6
(sh I) and
Q61, Rl88, Q62
bus to
Q61
16
SHORT CIRCUIT CURRENT DOESN’T CUT BACK.
CAUTION: DO NOT MAINTAIN A SHORTED LOAD IF CUTBACK FAILS TO OCCUR WITHIN 1 SECOND.
It will be necessary to measure the output current with a DC current probe, or by noting the voltage across
a low value resistance with a DC scope, in order to determine which output cell is failing to cut back.
Failure to cut back could indicate either lack of clamping, or lack of voltage cutback. Measure the voltage
on the respective clamp capacitor. If the voltage decreases, but current limiting does not cut back, check
the clamping transistor.
:
Page 21
CLAMPING VOLTAGE DECREASES, BUT NO CURRENT CUTBACK
CHANNEL-POLARITY CH
Measure voltage on:
Check clamp transistor
If the measured voltage on the clamp capacitor is not decreasing to about 50% during the short, check the
circuitry which measures the current during short circuit,
CLAMPING VOLTAGE DOES NOT DECREASE TO 50% DURING SHORT.
CHANNEL-POLARITY
Measure voltage on:
Missing cutback transistor, resistor
Missing voltage sense resistor,
Shorted or low value shunt resistor R72
I+
c21
Q18
CH
I+
c21
Q24,
R67
R 73 R 74
CH
c22
Q23
CH
c22
Q25,
R75
l-
l-
R68
CH
2+
C56
Q63 Q68
CH
2+
C56
Q69,
RI90
RI96RI97
RI95
CH
C5?
CH
c57
Q70,
RI98
2-
2-
RI91
Troubleshooting Thermal Tracking
MOUNTING PROBLEMS WITH IOK SENSING NTC.
The thermal sensing for fan and bias tracking depends on a 1 OK NTC which is mounted in a hole in the
heat sink. The hole is filled with thermal grease to improve coupling. If the NTC is not straight while
mounting the heat sink, it may short out against the side of its hole. It is mounted on a standoff which
protrudes into the hole, so this should not occur if care is taken while installing the heatsink.
If shorted to the heat sink, the amplifier output voltage is coupled to the NTC. If the short is to the grounded
lead of the
which will probably damage it.
SHORT FROM “LIVE” END OF NTC TO HEAT SINK:
Replace affected NTC
BE AWARE! This can short (relatively) quietly and then appear to be operating normally. Poor bias
tracking can indicate this problem. Sometimes this short will not happen until the amplifier is driven past IV
input.
NTC BENT OVER AND SHORTED TO DRIVER TRANSISTORS.
May touch
This causes severe overcurrent to the affected output cell, possibly damaging the parts in series with the
shorted transistor. It may also blow the power supply.
Replace affected
NTC,
it may not damage anything. If to the other end, a large voltage is put across the NTC
Ql9, Q26,
Ch 1:
Ch 2:
or
Q64, Q71.
NTC,
drive transistors, check components in series with drive transistor
Ql9
shorted, check,
Q26 shorted, check ALL outputs and opposing driver transistor on this channel.
Q64 shorted, check
Q71
shorted, check ALL outputs and opposing driver transistor on this channel.
R381, Q20, R70, DIO,
R383, Q65, Rl93, D35, D39.
D14.
17
Page 22
Audio Output, Troubleshooting Stability Feedback
HIGH FREQUENCY OSCILLATIONS
SEVERE-DRAWS CURRENT-GROSS DISTORTION
C27 (62) missing or wrong, or series R367 (368)
C 25, 26 (60, 61) missing
Secondary filter capacitors missing or open (unlikely that ALL are defective).
SEVERE, BUT DOES NOT DRAW LARGE CURRENT
R22 (146) open.
MARGINAL -- MAY APPEAR ONLY AS EXCESS DISTORTION
Cl4 (49) missing
Cl 6 (50) missing or too large
C28 (63) missing
C 25 or 26 (60 or 61) missing or too large
Cl95 or 196 missing (input board).
EXCESSIVE OSCILLATION JUST BELOW CLIPPING, 2-4 ohms
Cl 7 (52) missing
NOTE: about 0.1% oscillation right below clipping at 2 ohms is normal.
EXCESSIVE SWITCHING INTERFERENCE.
Switching interference may LOOK like an instability, however it is at a much lower frequency
most instabilities. It will be more visible at low frequencies
Missing jumper at
Missing
Grounds not connected to chassis at output board and front chassis mounting screw.
Cl29,
R224.
134 on output board.
(2OOHz)
and at lower impedances.
(1lOkH.z)
than
FEEDBACK PROBLEMS: GAIN INCORRECT
Gain of output stage set by
Gain of Ch 1 volume control buffer stage set by RI 1, 16.
Gain of Ch 2 volume control buffer stage set by
at Q48 should not affect gain. Check RI 32 (drives Q48).
Gain of balanced input is set by 4 matched resistors
of balanced input are working. Check
R23,
31 (147, 153)
R5,
6 (123, 124).
Rl37,
139. Make sure
R9,
8, 12, 13 (129, 130, 135, 136). Confirm both sides
Q48
is turned on - grounding
Audio Output, Troubleshooting Clipping, Limiting
EXCESS STICKING (TOO MUCH DISTORTION DURING CLIP LIMITING)
Cl4 (49) much too large (also causes increased high frequency distortion).
R38 (161) missing.
R38-39
(161-162) have wrong values.
Q9,
10 (54, 55) missing
R34 (157) or
Q8
(53) missing
R35
(158) missing
RI37
18
Page 23
CLIP LIMITING DOESN’T WORK:
BOTH CHANNELS:
Check U3 missing,
Check U3 supply voltages, +I
ONLY ONE CHANNEL BAD:
Probe output of U2
R38 (161) missing.
R38-39 (161-162)
Q9,
10 (54, 55) missing.
R34 (157) or
Q8 (53) missing
(7),
pin 7 while clipping. If output exceeds 4V during clipping, check
have wrong values.
R35
(158) missing
3VCL, -13VCL,
on
C73*
74
:
If output at pin 7 clamps at
R32 (154) missing
Q7 (52) missing
R28 (151) missing
Q6 (51) missing
RI8
(141) missing
RI9 (142) missing
SW I:1(1:lO) not making contact
Check each pin on U3
CLIP LIMITING OSCILLATES:
Cl 3 (48) missing.
R21,
27 (144, 150) missing
3.5.4V
as expected, check parts surrounding U3:
Troubleshooting Step Problems
EXCESSIVE STEP DISTORTION (STEP GLITCH)
Close scrutiny of the distortion trace, and scope probing of the switched waveform, will help determine the
cause of excess step distortion, The step should switch when the output voltage is within IO-12 volts of its
respective rail, This switching margin should be fairly constant from
should be a fairly uniform up and down ramp, moving at about 25 volts/us, therefore taking about
complete its transition.
Step Switching Too Close to
This will cause increased step glitch, especially at low impedances. If present at all frequencies,
check the reference voltages:
Negref: 17.5 volts above its intermediate rail:
PosRef:
20V below its intermediate rails:
the
Rail:
D88, R276-7-8.
D87, R256,
257,
20-
20kHz. The switching event itself
D53.
2us
to
Confirm correct values in output voltage divider: R48 loaded by
only at high frequencies, check the value of the speed up capacitor
or look for slow switching (see below).
R49-50 (Rl71,
C20 (C55)
and
Rl72-173).
in the output voltage divider,
If present
19
Page 24
Step Chattering.
If the step repeatedly switches on and off, usually at a low frequency, it creates an oscillation burst
which increases step glitch at low frequency. The tendency is usually worse at low impedances
and low frequencies. 2-3 “false trials” at very low frequency, 2 ohms, is normal, but prolonged
bursts of maximum frequency chattering may cause FET failure.
Slow switching reduces step glitch but puts more strain on the FET. Fast switching increases step
glitch. The usable limit is
If both slopes are equally off speed, check the slope capacitors:
Positive,
If only one slope is slow, check the resistors and buffer transistors:
Positive step:
Negative step:
Step FET Oscillation.
Certain FET types oscillate at extremely high frequency while ramping up and down. This injects
interference into the amplifier which increases the step glitch. Such problems are supposed to be
found while
know.
STEP WON’T TURN ON (Premature Clipping)
If the step refuses to switch high, the amp will clip prematurely, at the intermediate rail, at any load. Make
sure the clipping is not
and intermediate rail voltages to confirm clip point and lack of step action. Trace the circuit from the step
FET back via gate drive to drive circuit to locate cracks, missing part etc. Check DC power on step driver
(14V
on EACH positive step drivers,
+65V
rail) or Negref
ladders.
C30 (C65)
R78,
R83,
(dis)qualifying
acually
(17.5V
above
17-27
volts/us,
and Negative, C29 (C64).
79,
Dl5, Q30-31 (R201,
84,
Dl7, Q32-33 (R206,
specific FET types. If they crop up in production, Engineering needs to
current cutback, usually evident only at 2 ohms. Probe the output voltage
12V
on BOTH negative drivers). Check voltage of
-65V
rail). Look for severe mismatches of the comparator resistor
202,
207,
D40, Q7576)
D42, Q77-78).
PosRef
(20V below
STEP STUCK ON (Switched Rail Voltage Stuck On Full)
If the positive step is stuck on, (evidenced by permanent high voltage on switched rail) the FET is probably
bad, since the positive gate drive cannot sustain DC turn-on due to the bootstrapping. If the negative step
is stuck on, it could be a bad
confirmed by measuring the gate voltage. Malfunctioning gate drive circuitry should be checked as noted
above under “Won’t Turn On”.
REPEATED FET FAILURE.
Repeated failure of step
region). The actual failure usually occurs at 2 ohms, where the dissipation is highest. After replacing the
FET,
the step waveform should be monitored, starting at light load to avoid repeated failure, and advancing
briefly to heavier loads while closely watching the waveform. You will need to use an isolated scope probe
which allows voltage readings to be taken with respect to the intermediate rails, or to FET sources.
FET Does Not Fully Turn On:
Generally causes problems at low frequency, 2 ohms.
Confirm that the step FET remains fully on for the entire cycle
drive and determine cause.
Weak positive drive: check voltage on C32
missing D18
Weak negative drive: check voltage on
FET,
or the gate drive circuit could be holding the FET on, which will easily be
FET’s
is usually caused by failure to fully switch ON or OFF (lingering in the linear
(2OHz).
If not, confirm weak gate
(C51)
for
14V.
(Dl48).
Check
R78, Dl5, Q30 (R201, D40,
C67, 12V.
Check
Check
Q75).
R83, Dl7,
C31 (C66),
Q32
(R206, D42,
low RIO4
(R227),
Q77).
20
Page 25
FET Turns On or Off Very Slowly:
Generally causes problems at high frequency, 2 ohms.
If both slopes are equally slow, check the slope capacitors:
Positive,
If only one slope is slow, check the resistors and buffer transistors:
Positive step:
Negative step:
Severe Step Oscillation.
Generally observed at low frequency, low impedance, right at threshold.
NORMAL BEHAVIOR OF THE CIRCUIT.
Any amplifier fault which causes a non-symmetrical output, such as premature clipping of one polarity, a
missing step,
TRACING THE CAUSE OF FALSE TRIGGERS.
If amplifier is shutting down for no apparent cause, the source of the false signal must be found. Be sure the
output is checked with a DC coupled scope in order to confirm absence of an actual DC offset. The circuit
will trip on DC offsets exceeding about
etc,
may trigger DC fault shutdown. This indicates normal operation of the circuit
4V.
The optocoupler’s input can be safely disabled by shorted
triggering is before or after
The output of
signal.
SHUTDOWN OCCURS AS SOON AS SWITCHING STARTS.
Disable
series with AC line to limit fault current in case of shorted outputs.
If amplifier output looks OK, check UlO:l output. If low, check voltage on pins 2 and 3
UlO:l,
UlO:l,
Check R348 at Ul.5.
SHUTDOWN OCCURS ABOVE ABOUT 4V OUTPUT:
Q87, C7, R240
Confirm D48 is pulled low
NOTE: this control voltage responds to the Br Mono switch, pole
Check R348 at
Bad connection at step diodes
UlO:l,
Ul5
as noted above, determine if there is a DC fault condition. CAUTION: use
pin 2: should be zero (no signal)
pin 31 should be about
or D48 missing.
Ul5.
Ul5.
pin 1 should be monitored. If it goes low during DC shutdown, it is sending the false
2V!
set by
(-13V),
holding Q87 on. If not, check RI 17, 118, Q42
(D21, D22, D46, D47)
R243,
244, 245.
Ul5,
pins I-2 together. This will indicate if false
7.
50-ohm
resistor in
21
Page 26
Fan Speed Troubleshooting
FAN STUCK HIGH:
Q88
or Q89 failed
R30
or
Rl55,
Thermal Sense
R266 or
FAN DOESN’T RUN
Check fan voltage, should be 1 IV when cold, 29V when hot.
Voltage OK -- replace fan.
No Voltage: check
R271
missing.
Q91,
NTC,
shorted to
89, 90, R264 and 265 missing. Confirm that
heatsink
+/-15V
is reaching circuit.
22
Page 27
PLX 1202 PCB ASSEMBLY
(12OV)
PLX 1202 PCB ASSEMBLY
(12OV)
Cont’d
Part Number
CA-01 0002-30
CA-01
5002-10
CA-I 10002-30
CA-I 33001-10CAP SM 330PF 5% 500V
CA-I 47003-30CAP 470PF 5%
CA-168003-30CAP CER 68OPF 5%
CA-21
0005-30
CA-222001-00CAP CER Y
CA-227001-30CAP CER .0027UF 10%
CA-233001-10 CAP MYLAR
CA-233002-00CAP CER Y
CA-322001-10 CAP MYLAR
CA-410001-00 CAP MET POLY
CA-410002-10 CAP MYLAR
CA-410003-10 CAP MET POLY
CA-410006-30CAP CER
CA-410011-00 CAP MMYL
CA-422001-10 CAP MYLAR
CA-447001 -00 CAP MET POLY
CA-447003-00 CAP POLYP
CA-51 0005-30
CA-510006-00 CAP MPOLY X
CA-61 0002-10 1 OUF,35V,2O%,RADlAL
CA-647001 -10
CA-647002-1 0
CA-71 0002-10
CA-71 0004-10
CA-747001 -10
CA-747004-00 CAP LYTIC RL 47OUF 20%
Description Reference
CAP 1 OPF 5% 50V 0805 SMT
CAP CER
CAP CER 1 OOPF 5%
CO-000036-CO SPEAKONS, PC MOUNT J7,8
CO-000148-00 CONN XLR F VERT PCB
CO-000155-00 HEADER PCB ,100 2-POSITION
CO-000162-00 BNDG POST A, DUAL SLOT, PLX
CO-000163-00 BNDG POST
CO-3001
HW-OOOOOI-FC FUSE CLIPS
IC-000024-00
IC-000047-30 IC
IC-000048-30 IC
IC-000051-00 IC
IC-000053-30 IC
IC-000054-30 IC
IC-000073-30 IC
IC-000134-00 IC CMOS HV DRVR
IC-000135-00 IC
IC-005532-OPIC
MS-000048-HS
MS-0001 12-00 FUSE
PC-000531-00 PCB MAIN PLX
PL-000114-00
PL-000726-00 SPRING, SEAT, PLX
PL-000128-00 SPACER, LED,
PL-000135-00 INSULATOR, MICA 1.25” X 1.75”
PL-905156-SP
PT-125000-AT RES VAR IT 250 20%
PT-310000-CR
QD-000014-QD
QD-000042-00 DIODE RECT ULTRAFAST 400V 3
QD-000052-00 LED GRN T-l
LABEL, CE LISTING
LABEL, INPUT/OUTPUT, PLX
LABEL, FACEPLATE PLX 1202
LABEL, FUSE, UL CAUT.
-IL
318”
INTERNAL TOOTH LOCKWASHER
AC CORD PROTECTOR
STRAIN
POT COVERS
KNOB FAB.
EXPORT BINDING POST PLUG(RED)
EXPORT BINDING POST PLUG(BLK)
CLIP XMAS-TREE SLG HEAD FASTEX
FAN INTERFACE PLX
CH-000102-00
CH-000103-00
CH-000104-00
CH-0001 1 I-00
CH-000114-00
CO-000036-CO SPEAKONS, PC MOUNT
CO-000148-00 CONN XLR F VERT PCB
CO-0001 55-00
CO-000162-00 OBS-BNDG POST
CO-000163-00 OBS-BNDG POST
CO-3001
HW-OOOOOI-FC FUSE CLIPS
PL-000095-00
PL-000096-00 lNSULATOR,FAN
SC-025000-PP SCREW M2.5 X 6MM TYPE 1 PH BLK
SC-060060-PS SCREW 6-32 X
SC-082051-PL
SW-000016-S
WC-000134-00 AC CORD
WP-000057-00 FAN
WP-000541-02
CHASSIS, PLX
LBL,
FRENCH, FUSE REPLACEMENT
LABEL,WARNlNG,HlGH
LABEL, FACEPLATE PLX 3002
5-00
LABEL, INPUT/OUTPUT, PLX
LABEL, FUSE, UL CAUT.
RELlEF,LiQ.TlGHT,HEYCO
POT COVERS
EXPORT BINDING POST PLUG(RED)
EXPORT BINDING POST PLUG(BLK)
FAN INTERFACE PLX
SCREW,TAP,PAN PH#8X5/16”“B”BK
SPST SNAP IN POWER SWITCH
ASSY, 23OV,
ASSY,
3.15” 24VDC
PCB
ASSY,
PLX 3002 (230V)
ENERGY
15A
DUCT, PLX
,375
SEMS EXTL ZC
PLX
W/5.5L”
250V
49
Page 54
PLX Series
Semiconductor Identification
TMOS FET
TMOS Power Field Effect Transistor
lRFZ44
0
,
’
G
-6
43
AZ
OP-AMP
Dual Operational Amplifier
lRFZ4l
!?
G D S
NE5532AN
DRIVER TRANSISTORS
2SC4793
NPN
I2SAl837
PNP
BCE
POWER TRANSISTORS
2SC3281
NPN
I2SAl302
PNP
lC E
50
OP-AMP
Dual Operational Amplifier
TL072
SMALL SIGNAL TRANSISTORS
2N3904
NPN
I2N3906
PNP
C
Page 55
PLX Series
Semiconductor Identification
TIMER
Dual Timer
OP-AMP
Dual Transconductance Operational Amplifier
LM556CM
LMI 3600
PWM Switch
PWM MOSFET Gate Driver
OP-AMP
Dual Low Noise Operational Amplifier
TOP21 0
MC33078
COMPARATOR
Voltage Comparator
LM311
OPTO-ISOLATOR
Gallium Arsenide LED Coupled to
Phototransistor.
Moc8lol
51
Page 56
PLX Series
Semiconductor Identification
IGBT
PLX2402, PLX3002
insulated Gate Bipolar Transistor
PWM
Regulating Pulse Width Modulator
lRG4PC5OU
SG3525AN
IGBT
PLXI
202,
PLXl602
Insulated Gate Bipolar Transistor
c
lRG4PC4OU
lx
n-channel
k
G
‘2
E
c
HIGH/LOW SIDE DRIVER
High Speed MOSFET I
IGBT DRIVER
IGBT
Driver
VDD
Logic supply
HIN
Lcmic imul hiah
Lo& it-&l fo;
SD
LIN
Logjc
Lognc
vss
VB
High
HO
High
side
High side floating supply
vs
vcc
Low side
LO
Low side
COM
Low side return
input low side
ground
s!de
floating supply
output
sumlv
o&l
lR2110
side
shutdown
52
COMPARATOR
Low Power Dual Comparators
LM393NE
COMPARATOR
SOIC
Quad Comparator
LM339AM
Page 57
HANDLE-EAR
2
REDO
SCREW, #8 X
5/16’L 7
3
REQD
KNOB
J
2
REW
FACEPLATE LABEL
,.“..ce,c -
-
- cCREW, #6-32
RECQ
X
3/6* L., SEMS
CHASSIS ASSEMBLY
l HEX NUT
1. THIS
WRING
(NW-3BOBO3-HN)
DRAMNG
DIAGRAM SH-000540-00 AND FINAL ASSY
USED IN CONJUNCTION
PART OF
1/4-
PHONE JACK ON
%lTH
SCHEMATIC
FG-000540-XX.
ITEM
39 (PCB ASSY).
DWGs
MAIN PCB ASSY SH-000541-00,
MEW
A-A
Page 58
H
z
-----------
_-_-_-_-
Fi
G
g
u
Page 59
Q
55
Page 60
PLX MAIN
MOOULE
ASSEMBLY
smm,
+6-20 Y 5/r I_
1.w ’
Page 61
87654321
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
D
FILTERINPUT
POSITIVE
OUTPUTS
SPKR
OUTPUT
NEGATIVE
OUTPUTS
LED
DISPLAY
GAIN
POT
THERMAL
SENSING
LOOP GAIN
FEEDBACK
CLIP
LIMITING
CURRENT
SPLITTER
CHANNEL A
C
AUDIO CIRCUITS
SHEET 2
OP-AMP
SUPPLIES
POWER
SUPPLY
BLEEDERS
INPUT
FILTER
GAIN
POT
BR MONO ROUTING
LED
DISPLAY
EMI
FILTER
LOOP GAIN
FEEDBACK
INRUSH
RELAY
THERMAL
SENSING
CLIP
LIMITING
AC
RECT
CURRENT
SPLITTER
MAIN
FILTERS
POSITIVE
OUTPUTS
NEGATIVE
OUTPUTS
IGBT
SWITCHES
SPKR
OUTPUT
CHANNEL B
AUDIO CIRCUITS
SHEET 3
GATE
DRIVE
D
C
DC FAULT
B
SHUTDOWN
A
2. COMPONENTS WITH VALUE PREFIXED WITH A "^" REPRESENT SMT COMPONENTS.
1. THIS DRAWING USED IN CONJUNCTION WITH ASSEMBLY WP-001203-00.
NOTES: UNLESS OTHERWISE SPECIFIED
87654321
THERMAL
SHUTDOWN
FAN SPEED
TO MUTE
CONTROL
SUPPORT AND
PROTECTION
CIRCUITS
SHEET 4
SHUTDOWN
TRIGGERS
RELAY
CONTROL
BIAS
SUPPLY
OVERCURRENT
DETECTION
HIGH FREQ
TRANSFORMER
ISOLATED
HIGH FREQ
RECTIFIERS,
FILTER CAPS
WP-001203-00
NEXT ASSYUSED ON
APPLICATION
PLX 1202
SWITCHING
OSCILLATOR
ITEM NO.QTYPART NO.
UNLESS OTHERWISE SPECIFIED
DIMENSIONS ARE IN INCHES.
DIMENSIONS PER ANSI Y14.5-1982
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
D
J1
N1
J3:3
3
R
RING
J3:2
TIP
T
S
J3:1
1
N2
J3:4
4
2
3
N3
1
J2
SW1:5
SW1:6
DIP-10
DIP-10
515
616
+13IN
N23
N22
+XLR_B
-XLR_B
INPUTS IN PARALLEL
C
-SH3
N24
N28
R1
1.00K
^R_1206
N29
PARALLEL
INPUT SW.
STATUSLED
YEL
LD1
N30
B
LED-SIGNAL DISPLAY
N110
LD2
GRN
Q1
3906
^Q_BJTP_SOT-23
N112
Q2
LD3
GRN
3906
^Q_BJTP_SOT-23
N114
Q3
LD4
GRN
3906
^Q_BJTP_SOT-23
^Q_BJTP_SOT-23
A
CLIP
RED
LD5
87654321
SH 4, EURO-INPUTS
J4:3
J4:2
J4:1
J4:4
A-1 GND
A-4, GND
A-2 +A
A-3 -A
C195
.001-5%
^C_1206
SW1:4
DIP-10
J3:20
20
A-20, +13V
N31
CWCCW
W
VR2
GAIN
10K-THRU-PCB
N33
Q4
3906
N119
+IN_CH-A-IN_CH-A
N4
^R_0805
3
2
1
4
^R_0805
DATAPORTCONNECTED TO INPUT
AS USUAL TO MINIMIZE CROSSTALK
WHEN USING REGULAR INPUTS
AMP LOOP GAIN -- 32DB REVISION
USE SAME VALUEAS PLC-2
NTCBUS
N46
D3
N45
C15
100-25V
R36
R37
N42
+13VCL
R33
100K
^R_0805
N136
R34
1.50K
^R_0805
N133
Q8
3904
R35
1.50K
^R_0805
4148
^D_SOT-23
R41
1.50K
^R_0805
9.09K
^R_0805
475
^R_0805
R38
7.50K
N135
^Q_BJTP_SOT-23
R39
1.50K
P
N230
R101
1.50K
^R_0805
VR43
N44
N43
D4
D5
C17
^C_1206
^R_0805
470pF-50V-5%
Q12
3906
N137
R42
1.00K
^R_0805
^R_0805
CLIP-LIMIT
PROCESSOR
N47
TH-SUBC-A
N49
250
CWCCW
W
4148
^D_SOT-23
4148
^D_SOT-23
-15NTC
R106
12.7K
^R_0805
Q13
3904
^Q_BJTN_SOT-23
^R_1206
R44
383
R47
R45
C18
100pF-50V-5%
R46
12.7K
^R_0805
N89
N87
4148
^D_SOT-23
DATAPORT, SH 4, CLIP A
N138
2.21K
^R_0805
P
POS STEP DRIVER
N51
+15NTC
N48
15.0K
^R_0805
N50
^C_0805
N88
C20
.0027
^C_0805
R48
2.00K
^R_0805
MUTE_HI
D89
SH 4
PROT
SH 3
CLIP_A
C19
^C_1206
.1-50V-10%
R49
POSREF
N54
47-50V
^Q_BJTP_SOT-23
R51
P
FULL MUTE, 5.7V
N90
SEE SH 4
P
R53
47-50V
^Q_BJTN_SOT-23
R50
15.4K
^R_1206
15.4K
^R_1206
C21
Q14
3906
100K
^R_1206
MUTE+
^Q_BJTN_SOT-23
P
^Q_BJTP_SOT-23
100K
^R_1206
C22
Q15
3904
N98
DC_SENSE
N139
N56
N63
N62
N61
+HI-RAIL
N57
N53
N52
N55
N59
N60
D
N58
.36W at full clip
POS OUTPUT SECTION
C23
.0027
Q24
3906
^Q_BJTP_SOT-23
N65
R381
100
^C_1206
^R_0805
.1-50V
^C_1206
R382
100
^R_0805
^Q_BJTP_SOT-23
R67
^R_0805
^C_0805
N66
Q18
3904
^Q_BJTN_SOT-23
N477
N83
R70
R71
N478
Q23
3906
N67
Q19
2SC4793
Q20
2N3904
100
100
Q21
2N3906
N94
Q22
2SA1837
R72
R73
N78
N84
^R_0805
^R_0805
N93
N95
2.00K
^R_0805
^D_SOT-23
100K
^R_1206
C25
C26
12.7K
^R_0805
680pF
470pF
R59
5.90K
^R_0805
R60
39.2K
^R_0805
N64
+15NTC
C179
.1-50V
P
Q16
300V-.2A
N91
R65
12.7K
^R_0805
N92
Q17
300V-.2A
P
C180
-15NTC
N97
N96
274
N101
R74
100K
R76
Q25
^R_0805
3904
^Q_BJTN_SOT-23
R61
39.2K
N99
C24
.0027
^C_0805
R62
5.90K
^R_0805
274
R68
^R_0805
^D_SOT-23
^R_1206
N100
12.7K
^R_0805
R75
2.00K
^R_0805
^D_SOT-23
D9
4148
D10
^C_0805
^C_1206
D11
4148
R77
4148
N79
N85
D8
274
R81
N68
N70
MJE15033
D14
4148
^D_SOT-23
4148
D16
^D_SOT-23
200V-.2A-50NS
^D_SOT-23
SPKR_BUS_A
N466
C27
.022
R80
5.6-2W
D13
200V-.2A-50NS
^D_SOT-23
4148
^D_SOT-23
MJE15032
D12
274
R82
R91
R88
R85
15-2W
^R_0805
N72
2SA1302
Q26
N71
Q28
I-MON SH 4
L-Z_A1
N77
N81
2UH-14GA-AIR
C28
R367
15-2W
Q27
.1-250V
R87
R90
15-2W
15-2W
PP1
N104
Q29
N102
2SC3281
N103
N105
R89
R92
R86
^R_0805
15-2W
P
R111
R107
R102
N74
N73
2SA1302
2SA1302
Q36
Q39
N80
D
L1
12
R98
5.6-2W
N86
R93
15-2W
PWR-GND, TO SUPPLY CT
Q37
Q40
2SC3281
2SC3281
N107
N106
R103
R108
R112
8PL
R113
.47-2W
D19
SPKR-A
N82
E9A
E10A
E10B
D20
8PL
R114
.47-2W
NEG OUTPUT SECTION
SH 4
NEGREF
N141
N144
N140
N145
N146
V-NEGSTEP
JUMPER
1N5402
E9B
1N5402
JUMPER
+MID-RAIL
D22
N76
N75
N461
C129
J7
.1-250V
E9C
1+
1-
N459
2+
2-
JACK-SPEAKON
BR-POS
BR-NEG
EMI_G
FROM CH B
SHEET 3
C
N462
E10C
B
DWG NO.
N108
D21
-MID-RAIL
N109
SH-001203-00
2
REVSH
B
A
N148
N147
N143
NEG STEP DRIVER
N142
-HI-RAIL
SIZE FSCM NO.DWG NO.
D
SCALECAD FILE NO.SHEET
NONE
SH-001203-00
plx1202a.sch
REV
B
2OF5
58
Page 63
87654321
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
D
OPAMP POWER SUPPLIES
C
BR-ON
SH 3
D48
4148
^D_SOT-23
R240
N332
^Q_BJTP_SOT-23
B
POWER LED
ON DISPLAYPCB
A
47-10NP-10%
N349
GRN
N350
N331
DC_SENSE
2.21K
^R_0805
SH 2, 3
R242
20.0K
^R_0805
P
Q87
3906
^D_SOT-23
C71
N333
^D_SOT-23
DC MUTING
J6:14
J5:14
14
LD11
J6:16
J5:16
16
D50
4148
D49
4148
14
16
N338
-DC THRESH, -4V
N339
+DC THRESH 4V
R241
12.7K
^R_0805
N348
R243
R244
R245
DP-PAR-F
N330
D
N366
SH 2
DP-BR-F
SH 3
D
N291
SEE SH 2
TH-SUBC-A
I-MON CH A
THERMAL SUBCODE)
N326
+13VCL
D
N358
SEE SH 3
TH-SUBC-B
I-MON CH B
(WITH SEP.CH B
THERMAL SUBCODE)
N367
V-MON CH A
(NEW BMF SUBCODE,
0-2V,0.5V BITS)
INJECT V-DC
POST OPAMP,
NO GAIN SCALING
D
(WITH SEPARATECH A
V-MON CH B
(PWR-SUPPLY-ON
SUBCODE: .8-1.3V)
SCALE 13V TO 1V NOM
N359
D
+15V
FOR 1/8 WATT:
110MA, 1.1V MAX
N292
-IN_DPA
+IN_DPA
+IN_DPB
-IN_DPB
+IN_CH-A
-IN_CH-A
SEE SH 2
CLIP_B
+IN_CH-B
-IN_CH-B
A1
N293
N294
N295
N296
CLIP_A
N304
N305
N306
N307
N315
N316
SET ID- R
A1
N313
N317
N460
N297
N298
N299
N300
N301
N302
N303
N308
N310
N311
N318
N319
N320
N321
N312
N314
EURO-PLUG:
RAVESIGNAL
FORMAT
DATAPORT
HD-15 JACK
EURO-PLUG:
RAVESIGNAL
FORMAT
+A
-A
GND
-IN, A
STBY
VMON-A
IMON-A
CLIP-A
CHAS GND
+IN, A
+IN, B
+15V ??
D-REF
-IN, B
IDR
VMON-B
IMON-B
CLIP-B
+B
-B
GND
D
C
B
DWG NO.
SH-001203-004
CH GND
REVSH
B
D
A
+15V
R246
39.2
+13VCL
^R_1206
R248
N282
39.2
+14VIC+11V
^R_1206
N286N287
N283
DC-OFF
R250
C76
470-16V
C77
470-16V
-14VIC-11V
39.2
R249
^R_1206
N284
DP - STBY
1.00K
^R_1206
+MID-RAIL
D87
R256
N468
470-2W
N285
JUMPER
POSREF
C191
R224
.1-50V
^C_1206
A1
0.7 JUMPER
N288
R276
R277
R278
470-2W
470-2W
470-2W
N469
N322
V-NEGSTEP
C73
470-16V
P
C74
470-16V
-13VCL
39.2
R247
^R_1206
-15V
TO SHUTDOWN OPTOCOUPLER, SH 5 (6V)
TO OPTOCOUPLER LED
N335
1.6V OF HYSTERESIS
+HI-RAIL
PLC-2 USES MID RAILS ONLY
+MID-RAIL
TO PWR SUPPLY C-T
P1
NEGREF
D88
JUMPER
-MID-RAIL
ROUTE TO SPKR OUTPUT
SPKR-A
CH A V-MON, I-MON
N324
OUTER COIL, 6T
L-Z_A1
N323
+11V
N289
P1
N290
-11V
D
N327
N325
D
N69
N328
N329
N336
-HI-RAIL
TO SHEETS 2 AND 3
MUTE+
J13:1
1
J13:2
2
C89
+FAN
-FAN
ROUTE TO SPKR OUTPUT
SPKR-B
CH B V-MON, I-MON
N361
L-Z_B1
N360
OUTER COIL, 6T
+11V
N356
P1
N357
-11V
D
N149
N363
N364
N362
D
N365
39.2K
20.0K
C75
12.7K
^R_0805
^R_0805
.001-5%
^LM393-SMT
^R_0805
^C_1206
U10:1
3
2
SH 5
V-STBY
N337
+
-
R232
R370
84
1.00K
634
100-25V
1
^R_1206
^R_1206
C72
SEE SH 5
N334
15V-SW
N340
R252
D90
100-25V
100-25V
R251
-MID-RAIL
^D_SOT-23
10-35V
1.00K
^R_1206
4148
^D_SOT-23
C78
C79
3.9K-2W
D51
4148
N474
P1
+15NTC
-15NTC
D53
D54
NTCBUS
1N4744A
1N4744A
3906
Q88
R257
R258
P
N342
P1
470-2W
9.09K
^R_0805
FAN SPEED THRESHOLD
R259
12.7K
^R_0805
P
R260
392K
R261
^R_0805
39.2K
^R_0805
ON-OFF DELAY,
THERMAL THRESHOLD
THERM HYST
R263
392K
^R_0805
N345
R268
POS RAIL
FROM PWR SUPPLY OPTOCOUPLER, SH 5
100K
^R_1206
PS-OL
N346
R273
R270
1.50K
^R_0805
1.50K
^R_0805
FULL MUTE, 5.7V
FULL CUTBACK, 2.8V,1MA
N343
C81
^R_0805
4.75K
^R_0805
.001--5%
R253
^Q_BJTP_SOT-23
^C_1206
D55
4148
^D_SOT-23
N347
10-35V
C85
.001-5%
^C_1206
Q89
3904
^Q_BJTN_SOT-23
N344
U10:2
5
+
6
-
MUTE_HI
7
^LM393-SMT
D56
N352
R267
2.21K
^R_0805
6.2V-.3W
^D_ZEN_SOT-23
+15V
Q91
TIP 32C
R262
15.0K
C86
^R_0805
R264
N351
2.21K
^R_0805
R265
2.21K
^R_0805
N353
R271
20.0K
P
Q90
3904
^Q_BJTN_SOT-23
N354
R266
9.09K
^R_0805
N355
R272
9.09K
^R_0805
47-50V
^R_0805
N341
C80
R229
20.0K
60
FAN SPEED CONTROL
-15V
SIZE FSCM NO.DWG NO.
D
SCALECAD FILE NO.SHEET
NONE
SH-001203-00
plx1202a.sch
REV
B
4OF5
87654321
Page 65
87654321
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
J19
N368
1
F1
2
AC-HI
D
120, 240V
AC-LO
25A-125V
N371
J20
1
2
C
^Q_BJTN_SOT-23
D58
^D_SMB
MURS160T3
R321
N416
N417
R322
C107
.1-400V
B
DECLINES ABOUT 30% EVERY 35 MS
REACHES 8.7V IN 40 MS, (2 AC CYCLES)
R323
SET NOM PEAK AT13V, 120VAC
A
87654321
487K
487K
39.2K
X-CAPS, 3 PL
^R_1206
^R_1206
^R_0805
N372
N418
C108
L3:1
C110
1.0 250VAC
L3:2
+18V
D59
Q92
3904
.0027
^C_0805
PRI_LO
LINE FILTER SHIELD
13
C112
1.0 250VAC
24
C115
C118
.0033 250VAC
.0033 250VAC
+VREF
N373
4148
^D_SOT-23
RELAY25MA
R327
N406
Q93
R326
487K
8
9
-
+
^R_0805
C109
U13:3
LM339
3904
N411
14
.0027
^C_0805
^Q_BJTN_SOT-23
PRI_LO
NOM BUS VOLTAGE340V (120-240VAC)
MIN BUS VOLTAGE200-220V (75-150 VAC)
^R_1206
974K - 24.9K RES DIVIDER
340V NOM BUS = 8.67V
200V MIN BUS = 5.1V UV
R325
24.9K
C128
.0027
^C_0805
L4:1
L4:2
CH-GND
STUD
E11
RELAYSTARTS OFF LOW. 5V LINE
SETTLES HIGH BEFORE 16V > 8V,
BECAUSE TRIG IS LOW UP TO 10V
INRUSH LIMITING RELAY.
QSC-COM, 30A, COIL 24V
MIN VOLT18V, OK
N379
5
6
4
0V - RUN
5V - SHUTDOWN
10
11
N415
12
147
13
C120
.001-5%
^C_1206
C121
470pF-50V-5%
C192
N444
R336
R337
N446
R338
ES1
AC-SW
ES2
NC
NO
K1
{Value}
3
1
2
C126
.1-250V-X
240V,FULL
WAVERECT
EL1
120V,VOLT
DOUBLER
N380
E120B
E240
E120A
600V-50A
120V,PAR
RECT DIODES
BR1
1
+
AC1
AC2
2
-
4
N383
PRI_LO
N384
N381
C132
3
2200-200V
N382
C133
2200-200V
J120
C122
8
TRIGGER
COMP
9
OUTPUT
RESET
CONTROL_V
THRESHOLD
DISCHARGE
FLIP-FLOP
COMP
U14:2LM556-SMT
^R_0805
R376
10.0K
XF-BIAS
N117
^C_1206
PRI_HI
P2P1
+16VN424
312
4
-
U13:1
5
+
LM339
C125
2
.1-50V-10%
R340
392K
^R_0805
^C_1206
470pF-50V-5%
N470
+16V
10.0K
R341
100K
12.7K
10.0K
^R_0805
N445
^R_0805
^R_0805
C124
PRI_LO
^R_1206
R342
100K
^R_1206
.001-5%
PARALLELWINDING ON
^C_1206
RESONANT INDUCTOR
34
^C_1206
N447
L6:2
N421
^R_1206
R343
100K
R344
100K
R345
100K
N420
.0022-250VAC
0.5-1 MA TO TRIGGER
6
5
4
PRI_LO
N448
^R_1206
^R_1206
D60
MURS160T3
^D_SMB
C127
U15
1
NC
2
3
NC
FROM DC SHUTDOWN,
SHEET 4
AVERAGELIMITING HAS
SEVERAL SECOND TIME
CONSTANTTO REACH
2.4V THRESHOLD,
AVECURRENT 20-25A
D61
^200V-.2A-50NS
^D_SOT-23
R346
XF-PRI
N422
600V TRACE
100PF @ 15KV ESD
100NF @ 15V BYPASS
20.0K
^R_0805
T1:2
S3S4
PRI_LO
R375
10.0K
^R_0805
T1:1
C135
DC-OFF
.0022-250VAC
N426
PRI_LO
470-16V
IGBT HEAT SINK
N370
E14
D62
MURS120T3
^Q_BJTP_SOT-23
N453
5
D
6
N/C
7
N/C
8
S
U16
TOP 210
+6 V
R348
^C_1206
.1-50V-10%
+16V
R347
N450
Q95
3904
^Q_BJTN_SOT-23
N451
N449
C131
PRI_LO
Q99
3906
^R_0805
N/C
N/C
2.21K
2.21K
1
2
3
+18V
C138
R374
536
4
C
3
2
1
S
^R_0805
N455
^R_0805
U17
NC
PRI_HI
PRI_LO
5V NOM
T1:3
NC
R351
30K-2W
TRANSFORMER
QUIET END
R352
30K-2W
100-25V-105C
N428N427
D67
R349
R356
N476
R353
10.0
^R_1206
S7S8
ISOL WINDING - 6V
6
5
4
PS-OL
SH 4
T2:1
P5P6P7
P3P2P1
XF-79
D63
4148
^D_SOT-23
D64
4148
^D_SOT-23
D65
4148
^D_SOT-23
D66
10V-.3W
^D_ZEN_SOT-23
4148
^D_SOT-23
39.2
^R_1206
N423
10.0
^R_1206
C142
100-25V
N454
^200V-.2A-50NS
^D_SOT-23
V-STBY
TO SH 4
+6 V
N458
D86
MURS160T3
^D_SMB
U18
1
LO
2
COM
3
VCC
4
5
VS
6
VB9VDD
7
HO
IR2110
USE THRU HOLE,
HIGHER WATTAGE
470-100V
C169
470-100V
C170
+18V
14
13
VSS
12
LIN
11
SD
10
HIN
8
470-100V
470-100V
+HI-RAIL
+MID-RAIL
P1
-MID-RAIL
C185
PRI_LO
+VREF
^C_1206
.1-50V-10%
N398
N397
R360
C181
N399
16
15
14
13
12
11
10
9
7.87K
^R_0805
N385
C123
R373
C144
.47-400V
5.6-2W
.1-400V
N425
D69
4148
^D_SOT-23
+16V
C139
PRI_LO
N472
C113
N386
12
.0033
XF-79
100-25V
L6:1
R372
56-2W
T2:2
N394
N388
R354
C145
D70
5.6-2W
330p-500V
N387
MUR440
Q96
IRG4PC40
CE
G
D78
^200V-.2A-50NS
^D_SOT-23
N390
^R_1206
R359
10.0
C155
^C_1206
.1-50V-10%
+16V
C163
^C_1206
.1-50V-10%
N391
R355
N389
C146
5.6-2W
330p-500V
Q97
IRG4PC40
CE
MUR440
G
D71
N392
^R_1206
D79
^200V-.2A-50NS
^D_SOT-23
R358
10.0
2 BEADS IN PARHI RAIL
1 BEAD LO RAIL
N393
C162
N395
^C_1206
.1-50V-10%
PRI_LO
N435
N436
N429
S11
S12
N430
S13
S14
D74
200V-15A
D80
N437
200V-15A
S15
S16
S17
N431
S18
N432
S19
S20
N433
N434
P1
D75
200V-15A
D81
N438
200V-15A
L9
12
6UH-BEAD
L10
12
6UH-BEAD
C152
C153
470-100V
470-100V
C159
C160
470-100V
470-100V
C165
C166
470pF-50V-5%
-HI-RAIL
TO TURN-OFF MUTING
SHEET 4 (FAN SPEED)
15V-SW
D76
+15V
MURS120T3
D68
R357
N456
C143
C148
100-25V
P
39.2
^R_1206
MURS120T3
MURS120T3
^C_1206
470pF-50V-5%
MURS120T3
D82
D77
D83
^D_SMB
C149
100-25V-105C
C150
100-25V-105C
NEW, LO-ESR, 2PL
C156
C157
.1-250V
P1
.1-250V
-15V
U19
VREF
VIN
OUTB
VC
OSC.OUT
GND
OUTA
SHTDWN
DISCHG
COMP8SFT-SRT
SG3525AN
^R_0805
N441
R361
536
^C_1206
+16V
1
-IN
2
+IN
3
SYNC
4
5
CT
6
RT
7
^C_E_ALUM_B
R362
R363
N440
N442
N443
C182
PRI_LO
C183
^C_1206
.1-50V-10%
PRI_LO
N402
N403
^R_0805
N404
C184
1-50V
4.75K
^R_0805
N439
^Q_BJTP_SOT-23
10.0K
^R_0805
6
TRIGGER
5
OUTPUT
4
RESET
3
CONTROL_V
2
THRESHOLD
1
DISCHARGE
^C_1206
470pF-50V-5%
R364
100
PRI_LO
+VREF
+VREF
N400
R365
C116
.1-50V-10%
^C_1206
Q98
3906
COMP
FLIP-FLOP
COMP
N401
N405
15.0K
C186
^R_0805
PRI_LO
U14:1LM556-SMT
^C_1206
470pF-50V-5%
R366
10.0K
D
C
^R_0805
B
DWG NO.
SH-001203-00
5
REVSH
B
SMT-B PKG OK
N452
SIZE FSCM NO.DWG NO.
D
SCALECAD FILE NO.SHEET
NONE
SH-001203-00
plx1202a.sch
5OF5
A
REV
B
61
Page 66
87654321
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
REVDESCRIPTION
PRODUCTION RELEASE PER ECO 3724 ACA
B REVISE PER ECO 3803 AC8-28-98
REVISION
6-26-98
CHKEFF.DATEAPPROVED / DATE
TS 6/30/98KM
D
FILTERINPUT
POSITIVE
OUTPUTS
SPKR
OUTPUT
NEGATIVE
OUTPUTS
LED
DISPLAY
GAIN
POT
THERMAL
SENSING
LOOP GAIN
FEEDBACK
CLIP
LIMITING
CURRENT
SPLITTER
CHANNEL A
C
AUDIO CIRCUITS
SHEET 2
OP-AMP
SUPPLIES
POWER
SUPPLY
BLEEDERS
INPUT
FILTER
GAIN
POT
BR MONO ROUTING
LED
DISPLAY
EMI
FILTER
LOOP GAIN
FEEDBACK
INRUSH
RELAY
THERMAL
SENSING
CLIP
LIMITING
AC
RECT
CURRENT
SPLITTER
MAIN
FILTERS
POSITIVE
OUTPUTS
NEGATIVE
OUTPUTS
IGBT
SWITCHES
SPKR
OUTPUT
CHANNEL B
AUDIO CIRCUITS
SHEET 3
GATE
DRIVE
D
C
DC FAULT
B
SHUTDOWN
A
2. COMPONENTS WITH VALUE PREFIXED WITH A "^" REPRESENT SMT COMPONENTS.
1. THIS DRAWING USED IN CONJUNCTION WITH ASSEMBLY WP-000516-00.
NOTES: UNLESS OTHERWISE SPECIFIED
87654321
THERMAL
SHUTDOWN
FAN SPEED
TO MUTE
CONTROL
SUPPORT AND
PROTECTION
CIRCUITS
SHEET 4
SHUTDOWN
TRIGGERS
RELAY
CONTROL
BIAS
SUPPLY
OVERCURRENT
DETECTION
HIGH FREQ
TRANSFORMER
ISOLATED
HIGH FREQ
RECTIFIERS,
FILTER CAPS
WP-000516-00
NEXT ASSYUSED ON
APPLICATION
PLX 1602
SWITCHING
OSCILLATOR
ITEM NO.QTYPART NO.
UNLESS OTHERWISE SPECIFIED
DIMENSIONS ARE IN INCHES.
DIMENSIONS PER ANSI Y14.5-1982
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
D
J1
N1
J3:3
3
R
RING
J3:2
TIP
T
2
S
J3:1
1
N2
J3:4
4
2
3
N3
1
J2
SW1:5
SW1:6
DIP-10
DIP-10
515
616
+13IN
N23
N22
-XLR_B+XLR_B
INPUTS IN PARALLEL
C
-SH3
N24
20
N28
R1
1.00K
^R_1206
N29
PARALLEL
INPUT SW.
STATUSLED
YEL
LD1
N30
B
LED-SIGNAL DISPLAY
N110
LD2
GRN
Q1
3906
^Q_BJTP_SOT-23
N112
Q2
LD3
GRN
3906
^Q_BJTP_SOT-23
N114
Q3
LD4
GRN
3906
^Q_BJTP_SOT-23
^Q_BJTP_SOT-23
A
CLIP
RED
LD5
87654321
SH 4, EURO-INPUTS
-IN_CH-A +IN_CH-A-IN_DPA
N4
J4:3
^R_0805
3
J4:2
2
J4:1
1
J4:4
4
A-1 GND
A-4, GND
A-2 +A
A-3 -A
C195
A-20, +13V
N31
CWCCW
W
GAIN
N33
^R_0805
DATAPORTCONNECTED TO INPUT
AS USUAL TO MINIMIZE CROSSTALK
WHEN USING REGULAR INPUTS
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
D
OPAMP POWER SUPPLIES
C
BR-ON
SH 3
D48
4148
^D_SOT-23
R240
N332
^Q_BJTP_SOT-23
B
POWER LED
ON DISPLAYPCB
A
47-10NP-10%
N349
GRN
N350
N331
DC_SENSE
2.21K
^R_0805
SH 2, 3
R242
20.0K
^R_0805
P
Q87
3906
^D_SOT-23
C71
N333
^D_SOT-23
DC MUTING
J6:14
J5:14
14
LD11
J6:16
J5:16
16
D50
4148
D49
4148
14
16
N338
-DC THRESH, -4V
N339
+DC THRESH 4V
R241
12.7K
^R_0805
N348
R243
R244
R245
N330
D
N366
DP-PAR-F
SH 2
DP-BR-F
SH 3
D
N291
SEE SH 2
TH-SUBC-A
I-MON CH A
THERMAL SUBCODE)
N326
D
N358
SEE SH 3
TH-SUBC-B
I-MON CH B
(WITH SEP.CH B
THERMAL SUBCODE)
N367
D
V-MON CH A
(NEW BMF SUBCODE,
0-2V,0.5V BITS)
INJECT V-DC
POST OPAMP,
NO GAIN SCALING
D
(WITH SEPARATECH A
V-MON CH B
(PWR-SUPPLY-ON
SUBCODE: .8-1.3V)
SCALE 13V TO 1V NOM
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
J19
N368
1
F1
2
AC-HI
D
120, 240V
AC-LO
25A-125V
N371
J20
1
2
C
^Q_BJTN_SOT-23
D58
^D_SMB
MURS160T3
R321
N416
N417
R322
C107
.1-400V
B
SET NOM PEAK AT13V, 120VAC
DECLINES ABOUT 30% EVERY 35 MS
REACHES 8.7V IN 40 MS, (2 AC CYCLES)
R323
A
87654321
487K
487K
39.2K
X-CAPS, 3 PL
^R_1206
^R_1206
^R_0805
N372
N418
C108
L3:1
C110
1.0 250VAC
L3:2
+18V
D59
Q92
3904
.0027
^C_0805
PRI_LO
LINE FILTER SHIELD
13
C112
1.0 250VAC
24
4148
^D_SOT-23
RELAY25MA
N375
C115
C118
.0033 250VAC
.0033 250VAC
+VREF
N373
R327
N406
Q93
R326
487K
3904
N411
^Q_BJTN_SOT-23
PRI_LO
NOM BUS VOLTAGE340V (120-240VAC)
MIN BUS VOLTAGE200-220V (75-150 VAC)
^R_1206
N410N409
8
-
U13:3
14
9
+
LM339
974K - 24.9K RES DIVIDER
340V NOM BUS = 8.67V
200V MIN BUS = 5.1V UV
R325
24.9K
C109
.0027
^R_0805
^C_0805
C128
.0027
^C_0805
750K, X-CAP DISCHARGE
TO MEET IEC STANDARD:
BECAUSE X-CAP EXCEEDS 0.1UF
MUST DISCHARGE X-CAP TO
34 V WITHIN 2 SECONDS.
230V X 1.41 = 325V ->34 V
FOR C = 1.5UF,R < 628K, 0.1W
L4:1
13
C117
.47-250VAC
24
L4:2
CH-GND
STUD
E11
N309
RELAYSTARTS OFF LOW. 5V LINE
SETTLES HIGH BEFORE 16V > 8V,
BECAUSE TRIG IS LOW UP TO 10V
NTC NEXT TO RELAY
LOCATEDOWNSTREAM
OF FILTER,OUTSIDE SHIELD
INRUSH APPROX 0.5 SEC
EH1
R371
750K-1/2W
R335
150K
^R_1206
150K
^R_1206
N413
R334
100
^R_0805
C114
R332
39.2K
N419
5V NOM
R369
1.00K
^R_1206
4.75K
^R_0805
LM339
13
U13:4
LM339
1
U13:2
20.0K
^R_0805
EH2
PRI_LO
PRI_LO
N378
R324
10-OHM-20%
+VREF
N414
NON CRIT BYPASS
+VREF
C119
470pF-50V-5%
10-35V
PRI_LO
11
+
10
-
7
+
6
-
INRUSH LIMITING RELAY.
QSC-COM, 30A, COIL 24V
MIN VOLT18V, OK
N379
K1
5
6
4
0V - RUN
5V - SHUTDOWN
8
9
10
11
N415
12
147
13
C120
.001-5%
4
5
^C_1206
C121
C192
N444
R336
R337
N446
R338
NC
NO
3
1
2
TRIGGER
OUTPUT
RESET
CONTROL_V
THRESHOLD
DISCHARGE
^C_1206
+16V
312
-
+
^C_1206
470pF-50V-5%
N470
10.0K
^R_0805
N445
12.7K
^R_0805
10.0K
^R_0805
{Value}
C126
COMP
COMP
U13:1
2
LM339
R340
392K
^R_0805
+16V
R341
C124
PRI_LO
ES1
ES2
240V,FULL
WAVERECT
EL1
120V,VOLT
DOUBLER
FLIP-FLOP
100K
^R_1206
.001-5%
.1-250V-X
^R_1206
R342
100K
^C_1206
AC-SW
600V-50A
N380
E120B
120V,PAR
RECT DIODES
E240
E120A
U14:2LM556-SMT
C125
.1-50V-10%
COMBINED EFFECT OF
150K-1206 RESISTOR AND
10K, 12.7K THRESHOLD
RAISES PEAK LIMIT 25%
RELATIVETO PROTO
N447
L6:2
34
PARALLELWINDING ON
RESONANT INDUCTOR
^C_1206
BR1
2
N421
^R_1206
AC1
PRI_LO
PRI_HI
R343
100K
1
+
AC2
3
-
4
N382
N383
N384
R376
10.0K
^R_0805
R344
100K
^R_1206
R345
100K
^R_1206
MURS160T3
^D_SMB
N420
.0022-250VAC
0.5-1 MA TO TRIGGER
U15
6
NC
5
4
PRI_LO
AVERAGELIMITING HAS
SEVERAL SECOND TIME
CONSTANTTO REACH
2.4V THRESHOLD,
AVECURRENT 20-25A
N448
^200V-.2A-50NS
N381
N422
D60
C127
1
2
3
NC
FROM DC SHUTDOWN,
SHEET 4
D61
^D_SOT-23
R346
PRI ENERGY STORAGE, 6 PL
USE 4 PL FOR PLC-2
C132
2200-200V
C133
2200-200V
C122
.0022-250VAC
N426
T1:2
XF-BIAS
S3S4
PRI_LO
N117
R375
10.0K
^R_0805
P2P1
T1:1
XF-PRI
600V TRACE
100PF @ 15KV ESD
100NF @ 15V BYPASS
C135
DC-OFF
20.0K
470-16V
^R_0805
C136
2200-200V
C137
2200-200V
IGBT HEAT SINK
N370
E14
D62
MURS120T3
^Q_BJTP_SOT-23
N453
6
N/C
7
N/C
8
S
U16
TOP 210
PRI_LO
+6 V
R348
^C_1206
.1-50V-10%
+16V
R347
N450
^Q_BJTN_SOT-23
N451
N449
C131
PRI_LO
Q95
3904
2.21K
Q99
3906
^R_0805
C5D
N/C
N/C
S
2.21K
^R_0805
1
2
3
+18V
C138
R374
536
5V NOM
4
3
2
1
^R_0805
N455
U17
NC
NC
PRI_HI
R351
30K-2W
TRANSFORMER
QUIET END
R352
30K-2W
PRI_LO
100-25V-105C
D67
N424
N476
R353
10.0
^R_1206
T1:3
S7S8
ISOL WINDING - 6V
6
5
4
T2:1
P3P2P1
D63
4148
^D_SOT-23
D64
4148
^D_SOT-23
D65
N428N427
4148
^D_SOT-23
D66
10V-.3W
^D_ZEN_SOT-23
4148
^D_SOT-23
39.2
R349
N423
10.0
R356
C142
100-25V
N454
^200V-.2A-50NS
V-STBY
+6 V
PS-OL
SH 4
P5P6P7
N458
^R_1206
^R_1206
^D_SOT-23
TO SH 4
+18V
.1-50V-10%
N395
^C_1206
.1-50V-10%
470-100V
470-100V
^C_1206
PRI_LO
C165
C166
MURS160T3
^D_SMB
470-100V
470-100V
D86
U18
1
14
LO
2
13
COM
VSS
3
12
VCC
LIN
11
4
SD
5
10
VS
HIN
6
VB9VDD
7
8
HO
IR2110
USE THRU HOLE,
HIGHER WATTAGE
470-100V
C169
470-100V
C170
C173
C174
470-100V
470-100V
+HI-RAIL
+MID-RAIL
P1
-MID-RAIL
C185
PRI_LO
^C_1206
.1-50V-10%
N398
+VREF
N397
R360
C181
N399
16
15
14
13
12
11
10
9
7.87K
^R_0805
N385
C123
R373
C144
.47-400V
5.6-2W
.1-400V
N425
D69
4148
^D_SOT-23
+16V
C139
PRI_LO
N472
C113
N386
12
.0033
100-25V
L6:1
56-2W
R372
T2:2
N394
N388
R354
C145
D70
5.6-2W
330p-500V
N387
MUR440
Q96
IRG4PC40
CE
G
N390
^R_1206
D78
^200V-.2A-50NS
^D_SOT-23
R359
10.0
C155
^C_1206
.1-50V-10%
+16V
C163
N391
R355
N389
C146
5.6-2W
330p-500V
Q97
IRG4PC40
CE
MUR440
G
D71
N392
^R_1206
D79
^200V-.2A-50NS
^D_SOT-23
R358
10.0
2 BEADS IN PARHI RAIL
1 BEAD LO RAIL
C162
N393
N435
N436
N429
S11
S12
N430
S13
S14
D74
200V-15A
D80
N437
200V-15A
S15
S16
S17
N431
S18
N432
S19
S20
N433
N434
P1
D75
200V-15A
D81
N438
200V-15A
L9
12
6UH-BEAD
L10
12
6UH-BEAD
C152
C153
470-100V
470-100V
C159
C160
470pF-50V-5%
-HI-RAIL
TO TURN-OFF MUTING
SHEET 4 (FAN SPEED)
15V-SW
D76
+15V
MURS120T3
D68
R357
N456
C143
C148
100-25V
P
39.2
^R_1206
^C_1206
470pF-50V-5%
D82
MURS120T3
D77
MURS120T3
D83
MURS120T3
^D_SMB
C149
100-25V-105C
C150
100-25V-105C
NEW, LO-ESR, 2PL
C156
C157
.1-250V
P1
.1-250V
-15V
U19
VREF
VIN
OUTB
VC
OSC.OUT
GND
OUTA
SHTDWN
DISCHG
COMP8SFT-SRT
SG3525AN
^R_0805
N441
R361
536
^C_1206
+16V
-IN
+IN
SYNC
CT
RT
^C_E_ALUM_B
R362
R363
N440
N442
N443
C182
PRI_LO
C183
.1-50V-10%
PRI_LO
1
2
3
4
N402
5
6
7
N403
^R_0805
N404
C184
1-50V
4.75K
^R_0805
N439
10.0K
^R_0805
6
5
4
3
2
1
^C_1206
470pF-50V-5%
^C_1206
+VREF
N400
R364
100
R365
PRI_LO
+VREF
.1-50V-10%
^C_1206
Q98
3906
^Q_BJTP_SOT-23
TRIGGER
COMP
OUTPUT
RESET
CONTROL_V
COMP
THRESHOLD
DISCHARGE
C116
FLIP-FLOP
N401
N405
15.0K
C186
^R_0805
PRI_LO
U14:1LM556-SMT
^C_1206
470pF-50V-5%
R366
10.0K
D
C
^R_0805
B
DWG NO.
SH-000516-00
5
REVSH
B
SMT-B PKG OK
N452
SIZE FSCM NO.DWG NO.
D
SCALECAD FILE NO.SHEET
NONE
SH-000516-00
plx1602.sch
5OF5
A
REV
B
66
Page 71
87654321
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
D
INPUTFILTER
LED
DISPLAY
GAIN
POT
THERMAL
SENSING
LOOP GAIN
FEEDBACK
CLIP
LIMITING
CURRENT
SPLITTER
POSITIVE
OUTPUTS
SPKR
OUTPUT
NEGATIVE
OUTPUTS
CHANNEL A
C
AUDIO CIRCUITS
SHEET 2
OP-AMP
SUPPLIES
POWER
SUPPLY
BLEEDERS
INPUT
FILTER
GAIN
POT
BR MONO ROUTING
LED
DISPLAY
EMI
FILTER
LOOP GAIN
FEEDBACK
INRUSH
RELAY
THERMAL
SENSING
CLIP
LIMITING
AC
RECT
CURRENT
SPLITTER
MAIN
FILTERS
POSITIVE
OUTPUTS
NEGATIVE
OUTPUTS
IGBT
SWITCHES
SPKR
OUTPUT
CHANNEL B
AUDIO CIRCUITS
SHEET 3
GATE
DRIVE
D
C
DC FAULT
B
SHUTDOWN
A
2. COMPONENTS WITH VALUE PREFIXED WITH A "^" REPRESENT SMT COMPONENTS.
1. THIS DRAWING USED IN CONJUNCTION WITH ASSEMBLY WP-002403-00.
NOTES: UNLESS OTHERWISE SPECIFIED
87654321
THERMAL
SHUTDOWN
FAN SPEED
TO MUTE
CONTROL
SUPPORT AND
PROTECTION
CIRCUITS
SHEET 4
SHUTDOWN
TRIGGERS
RELAY
CONTROL
BIAS
SUPPLY
OVERCURRENT
DETECTION
HIGH FREQ
TRANSFORMER
ISOLATED
HIGH FREQ
RECTIFIERS,
FILTER CAPS
WP-002403-00
NEXT ASSYUSED ON
APPLICATION
PLX 2402
SWITCHING
OSCILLATOR
ITEM NO.QTYPART NO.
UNLESS OTHERWISE SPECIFIED
DIMENSIONS ARE IN INCHES.
DIMENSIONS PER ANSI Y14.5-1982
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
D
N1
J3:3
J1
3
R
RING
J3:2
T
TIP2
2
S
J3:11J4:1
1
N2
J3:4
4
2
3
N3
1
J2
SW1:5
SW1:6
DIP-10
DIP-10
515
616
+13IN
N23
N22
+XLR_B
-XLR_B
INPUTS IN PARALLEL
C
-SH3
N24
N28
R1
1.00K
^R_1206
N29
PARALLEL
INPUT SW.
STATUSLED
YEL
LD1
B
N30
LED-SIGNAL DISPLAY
N110
LD2
GRN
Q1
3906
^Q_BJTP_SOT-23
N112
Q2
LD3
GRN
3906
^Q_BJTP_SOT-23
N114
Q3
LD4
GRN
3906
^Q_BJTP_SOT-23
A
^Q_BJTP_SOT-23
CLIP
LD5
RED
87654321
SH 4, EURO-INPUTS
J4:3
J4:2
J4:4
A-1 GND
A-4, GND
A-2 +A
A-3 -A
C195
.001-5%
^C_1206
SW1:4
DIP-10
J3:20
20
A-20, +13V
N31
CWCCW
W
VR2
GAIN
10K-THRU-PCB
N33
Q4
3906
N119
+IN_CH-A-IN_CH-A
N4
^R_0805
3
4
^R_0805
DATAPORTCONNECTED TO INPUT
AS USUAL TO MINIMIZE CROSSTALK
WHEN USING REGULAR INPUTS
AMP LOOP GAIN -- 32DB REVISION
USE SAME VALUEAS PLC-2
NTCBUS
N46
D3
4148
N45
R41
1.50K
^R_0805
100-25V
R36
12.7K
475
R37
N42
R38
100K
^R_0805
N136
1.50K
^R_0805
N133
R39
Q8
3904
1.50K
^R_0805
N230
^D_SOT-23
^R_0805
N44
N43
^R_0805
D4
D5
C17
7.50K
^R_0805
N135
^Q_BJTP_SOT-23
N137
R42
1.50K
^R_0805
P
N47
TH-SUBC-A
N49
R101
1.50K
^R_0805
250
VR43
4148
^D_SOT-23
W
R45
CWCCW
C18
4148
100pF-50V-5%
^D_SOT-23
R46
12.7K
N89
-15NTC
^C_1206
N87
R106
470pF-50V-5%
12.7K
^R_0805
Q12
3906
Q13
3904
^Q_BJTN_SOT-23
1.00K
^R_1206
R44
383
^R_0805
DATAPORT, SH 4, CLIP A
N138
R47
2.21K
P
^R_0805
CLIP-LIMIT
PROCESSOR
N48
12.7K
^C_0805
^R_0805
D89
4148
^D_SOT-23
PROT
CLIP_A
C19
POS STEP DRIVER
^R_1206
POSREF
N54
N51
47-50V
^Q_BJTP_SOT-23
+15NTC
R51
P
^R_0805
N50
FULL MUTE, 5.7V
N90
N88
C20
P
R53
47-50V
R50
30.1K
^R_1206
R49
30.1K
^R_1206
MUTE_HI
SH 3
.1-50V-10%
.0027
^C_0805
R48
2.00K
^R_0805
SH 4
^C_1206
R52
150K
R54
150K
^R_1206
C21
Q14
3906
N64
100K
^R_1206
MUTE+
SEE SH 3
^Q_BJTN_SOT-23
P
^Q_BJTP_SOT-23
100K
^R_1206
C22
Q15
3904
^Q_BJTN_SOT-23
N98
DC_SENSE
SH 4
N139
R55
4.75K
^R_0805
R56
4.75K
^R_0805
N91
N92
N97
NEGREF
N140
^R_1206
^R_1206
R59
R60
300V-.2A
R65
300V-.2A
R61
R62
R57
150K
R58
150K
C179
Q16
12.7K
Q17
N141
4.75K
39.2K
P
P
39.2K
4.75K
^R_0805
^R_0805
^R_0805
C180
-15NTC
^R_0805
^R_0805
N143
D6
3.9V
N53
N55
D7
10V-1N4740A
.36W at full clip
C23
^Q_BJTP_SOT-23
+15NTC
.1-50V
^C_1206
^R_0805
.1-50V
^C_1206
N96
^Q_BJTN_SOT-23
C24
R2
47.5K
^R_0805
R63
4.75K
^R_0805
R64
4.75K
^R_0805
N56
N57
R66
392K
^R_0805
N52
U4
1
GND
2
3
4
V+
BAL/STR
V-
BAL
^LM311-SMT
POS OUTPUT SECTION
274
Q18
N66
^R_0805
N67
2SC4793
N83
Q20
R72
R73
N78
Q19
2N3904
R67
.0027
^C_0805
Q24
3906
3904
N65
^Q_BJTN_SOT-23
N477
R381
100
N84
75
R70
^R_0805
75
R71
^R_0805
N93
Q21
2N3906
N478
N94
Q22
R382
^R_0805
^Q_BJTP_SOT-23
Q25
3904
2SA1837
100
3906
N95
Q23
R74
N100
N99
274
^R_0805
C187
47pF-50V-5%
^C_0805
R75
.0027
^C_0805
R68
N396
R69
392K
^R_0805
N144
U5
1
GND
2
3
4
V-
^LM311-SMT
NEG STEP DRIVER
R78
5.90K
8
7
6
5
2.21K
^R_0805
R76
39.2K
^R_0805
N58
R79
3.01K
^R_0805
^R_0805
^D_SOT-23
R81
N68
D15
4148
N59
200
^R_0805
Q30
3904
^Q_BJTN_SOT-23
Q31
3906
^Q_BJTP_SOT-23
R88
R85
15-2W
D9
^D_SOT-23
100K
^R_1206
C25
C26
680pF
470pF
4148
D10
^C_0805
^C_1206
D14
4148
N79
^D_SOT-23
4148
^D_SOT-23
200V-.2A-50NS
^D_SOT-23
N85
C27
.022
5.6-2W
N70
MJE15033
SPKR_BUS_A
R80
2SA1302
Q26
N71
Q28
N77
D16
N466
C28
R367
15-2W
R87
PP1
D13
200V-.2A-50NS
^D_SOT-23
D11
4148
^D_SOT-23
Q27
200
N102
N103
^R_0805
N104
Q29
2SC3281
R89
R86
15-2W
100K
2.21K
^R_0805
^R_1206
N101
4148
^D_SOT-23
R77
39.2K
^R_0805
4148
^D_SOT-23
MJE15032
D12
D8
R82
NEG OUTPUT SECTION
N145
5.90K
4148
R84
2.21K
^R_0805
D17
N146
Q32
3904
^Q_BJTN_SOT-23
Q33
3906
^Q_BJTP_SOT-23
BAL/STR
R83
8
V+
7
6
5
BAL
C177
^D_SOT-23
^C_1206
.1-50V-10%
^R_0805
R91
.1-250V
15-2W
R92
2SA1302
L-Z_A1
N81
R90
2SC3281
C30
47pF-50V-5%
^C_0805
C31
10-35V
N60
R96
3.9K-2W
R97
R94
R102
N72
N73
2SA1302
Q34
Q36
I-MON SH 4
L1
12
2UH-14GA-AIR
R98
5.6-2W
N86
R93
15-2W
15-2W
PWR-GND, TO SUPPLY CT
Q37
Q35
2SC3281
N105
N106
R95
R99
R103
C29
47pF-50V-5%
^C_0805
R100
47.5
N147
^R_0805
R104
R105
P
R107
N80
R108
N61
12.7K
3.9K-2W
2SA1302
2SC3281
N148
N63
R110
47.5
^R_0805
^R_0805
R111
N74
Q39
D
Q40
N107
R112
N82
Q38
RFZ44
D18
C32
R113
R114
N142
N62
4148
100-25V
.47-2W
SPKR-A
E10A
.47-2W
V-NEGSTEP
-HI-RAIL
RFZ44
^D_SOT-23
8PL
1.5-2W
D19
E9A
D20
1.5-2W
8PL
Q41
R115
1N5402
E9B
E10B
1N5402
R116
15A-200V
D22
15A-200V
N75
N461
N108
D21
+HI-RAIL
+MID-RAIL
N76
C34
.1-250V
N459
C129
J7
.1-250V
E9C
1+
1-
2+
2-
EMI_G
BR-POS
FROM CH B
SHEET 3
JACK-SPEAKON
BR-NEG
N462
E10C
C35
.1-250V
N109
-MID-RAIL
SIZE FSCM NO.DWG NO.
D
SCALECAD FILE NO.SHEET
NONE
plx2402.sch
SH-002403-00
2OF5
D
C
B
DWG NO.
2SH-002403-00
REVSH
C
A
REV
C
68
Page 73
87654321
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
D
OPAMP POWER SUPPLIES
C
BR-ON
SH 2
D48
4148
^D_SOT-23
R240
N332
^Q_BJTP_SOT-23
B
POWER LED
ON DISPLAYPCB
A
47-10NP-10%
N349
GRN
N350
N331
DC_SENSE
2.21K
^R_0805
SH 1, 2
R242
20.0K
^R_0805
P
Q87
3906
^D_SOT-23
C71
N333
^D_SOT-23
DC MUTING
J6:14
J5:14
14
LD11
J6:16
J5:16
16
D50
4148
D49
4148
14
16
N338
-DC THRESH, -4V
N339
+DC THRESH 4V
R241
12.7K
^R_0805
N348
R243
R244
R245
DP-PAR-F
N330
D
N366
SH 2
DP-BR-F
SH 3
D
N291
SEE SH 2
TH-SUBC-A
I-MON CH A
THERMAL SUBCODE)
N326
+13VCL
D
N358
SEE SH 3
TH-SUBC-B
I-MON CH B
(WITH SEP.CH B
THERMAL SUBCODE)
N367
D
V-MON CH A
(NEW BMF SUBCODE,
0-2V,0.5V BITS)
INJECT V-DC
POST OPAMP,
NO GAIN SCALING
D
(WITH SEPARATECH A
V-MON CH B
(PWR-SUPPLY-ON
SUBCODE: .8-1.3V)
SCALE 13V TO 1V NOM
N359
D
+15V
FOR 1/8 WATT:
110MA, 1.1V MAX
N292
-IN_DPA
+IN_DPA
+IN_DPB
-IN_DPB
+IN_CH-A
-IN_CH-A
SEE SH 2
CLIP_B
+IN_CH-B
-IN_CH-B
A1
N293
N294
N295
N296
CLIP_A
N304
N305
N306
N307
N315
N316
SET ID- R
A1
N313
N317
N460
N297
N298
N299
N300
N301
N302
N303
N308
N310
N311
N318
N319
N320
N321
CH GND
N312
N314
EURO-PLUG:
RAVESIGNAL
FORMAT
DATAPORT
HD-15 JACK
EURO-PLUG:
RAVESIGNAL
FORMAT
+A
-A
GND
-IN, A
STBY
VMON-A
IMON-A
CLIP-A
CHAS GND
+IN, A
+IN, B
+15V ??
D-REF
-IN, B
IDR
VMON-B
IMON-B
CLIP-B
+B
-B
GND
D
C
B
DWG NO.
SH-002403-00
4
REVSH
C
A
+15V
39.2
R246
+13VCL
^R_1206
C73
470-16V
P
C74
470-16V
-13VCL
39.2
R247
^R_1206
R248
470-16V
470-16V
R249
-15V
N335
TO SHUTDOWN OPTOCOUPLER, SH 5 (6V)
TO OPTOCOUPLER LED
1.6V OF HYSTERESIS
DC-OFF
R250
1.00K
N336
C72
39.2K
20.0K
^R_0805
^R_0805
100-25V
N337
SEE SH 5
N334
-MID-RAIL
15V-SW
N340
R252
D90
C75
12.7K
.001-5%
^LM393-SMT
^R_0805
^C_1206
U10:1
3
2
SH 4
V-STBY
+
-
R232
R370
84
1.00K
634
1
^R_1206
^R_1206
N282
39.2
+14VIC+11V
^R_1206
C76
C77
39.2
^R_1206
N284
DP - STBY
^R_1206
+15NTC
D53
C78
C79
3.9K-2W
C80
N474
-15NTC
D54
NTCBUS
N341
R229
1N4744A
1N4744A
3906
C81
20.0K
^R_0805
P
Q88
100-25V
100-25V
R251
D51
4148
^D_SOT-23
10-35V
P1
1.00K
^R_1206
4148
^D_SOT-23
R253
4.75K
^R_0805
+MID-RAIL
D87
R256
R257
R258
N342
^C_1206
.001--5%
N468
^D_SOT-23
N347
N283
C191
N285
-11V-14VIC
1N4744A
150-2W
POSREF
C84
.1-250V
P1
820-2W
9.09K
^R_0805
FAN SPEED THRESHOLD
R259
12.7K
^R_0805
P
^Q_BJTP_SOT-23
D55
4148
.001-5%
^C_1206
.1-50V
^C_1206
A1
R261
R260
392K
^R_0805
N343
N344
R262
C86
10-35V
N351
C85
Q89
3904
^Q_BJTN_SOT-23
R224
0.7 JUMPER
39.2K
^R_0805
ON-OFF DELAY,
THERMAL THRESHOLD
THERM HYST
R263
392K
^R_0805
U10:2
5
+
6
-
^LM393-SMT
15.0K
^R_0805
R264
2.21K
^R_0805
R265
2.21K
^R_0805
^Q_BJTN_SOT-23
N354
P
R266
N286N287
R268
N345
7
D56
R267
2.21K
^R_0805
N352
N355
Q90
3904
9.09K
^R_0805
R269
C87
1.5-2W
.1-250V
R274
R275
R276
N288
R277
R278
N469
R279
N322
R280
V-NEGSTEP
100-25V
POS RAIL
FROM PWR SUPPLY OPTOCOUPLER, SH 5
100K
^R_1206
PS-OL
N346
R273
R270
1.50K
^R_0805
MUTE_HI
1.50K
6.2V-.3W
^D_ZEN_SOT-23
+15V
Q91
TIP 32C
R271
20.0K
^R_0805
R272
9.09K
^R_0805
470-2W
470-2W
470-2W
470-2W
150-2W
470-2W
0.7 JUMPER
C67
^R_0805
FULL MUTE, 5.7V
FULL CUTBACK, 2.8V,1MA
N353
47-50V
+HI-RAIL
PLC-2 USES MID RAILS ONLY
+MID-RAIL
TO PWR SUPPLY C-T
C90
.1-250V
NEGREF
D88
10V-1N4740A
-MID-RAIL
D57
12V-1W-1N4742A
-HI-RAIL
TO SHEETS 2 AND 3
MUTE+
J13:1
1
J13:2
2
C89
+11V
ROUTE TO SPKR OUTPUT
P1
SPKR-A
P1
N289
N290
-11V
CH A V-MON, I-MON
N324
OUTER COIL, 6T
L-Z_A1
N323
D
ROUTE TO SPKR OUTPUT
P1
SPKR-B
N325
D
N356
N69
N327
N328
N329
+11V
N357
-11V
CH B V-MON, I-MON
N361
L-Z_B1
N360
OUTER COIL, 6T
D
+FAN
-FAN
N362
D
N149
N363
N364
N365
70
FAN SPEED CONTROL
-15V
SIZE FSCM NO.DWG NO.
D
SCALECAD FILE NO.SHEET
NONE
SH-002403-00
plx2402.sch
REV
C
4OF5
87654321
Page 75
87654321
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
J19
N368
1
F1
2
AC-HI
D
120, 240V
AC-LO
25A-125V
N371
J20
1
2
C
^Q_BJTN_SOT-23
D58
^D_SMB
MURS160T3
R321
N416
N417
R322
C107
.1-400V
B
REACHES 8.7V IN 40 MS, (2 AC CYCLES)
R323
SET NOM PEAK AT13V, 120VAC
DECLINES ABOUT 30% EVERY 35 MS
A
87654321
487K
487K
39.2K
X-CAPS, 3 PL
N372
^R_1206
^R_1206
N418
^R_0805
C108
L3:1
C110
1.0 250VAC
L3:2
+18V
D59
Q92
3904
.0027
^C_0805
R325
PRI_LO
LINE FILTER SHIELD
13
C112
1.0 250VAC
24
4148
^D_SOT-23
RELAY25MA
N375
C115
C118
.0033 250VAC
.0033 250VAC
+VREF
N373
R327
4.75K
N406
Q93
R326
487K
3904
N411
^R_1206
^Q_BJTN_SOT-23
PRI_LO
NOM BUS VOLTAGE340V (120-240VAC)
MIN BUS VOLTAGE200-220V (75-150 VAC)
^R_1206
N410N409
8
-
U13:3
14
9
+
LM339
974K - 24.9K RES DIVIDER
340V NOM BUS = 8.67V
200V MIN BUS = 5.1V UV
24.9K
C109
.0027
^R_0805
^C_0805
C128
.0027
^C_0805
L4:1
13
C117
.47-250VAC
24
L4:2
CH-GND
STUD
E11
N309
RELAYSTARTS OFF LOW. 5V LINE
SETTLES HIGH BEFORE 16V > 8V,
BECAUSE TRIG IS LOW UP TO 10V
INRUSH LIMITING RELAY.
QSC-COM, 30A, COIL 24V
MIN VOLT18V, OK
R324
+VREF
147
NON CRIT BYPASS
C119
^C_1206
470pF-50V-5%
C192
10-35V
PRI_LO
N444
11
+
10
-
7
+
N446
6
-
N379
N415
C120
C121
NO
K1
5
6
4
1
0V - RUN
5V - SHUTDOWN
8
TRIGGER
9
OUTPUT
10
RESET
11
CONTROL_V
12
THRESHOLD
13
DISCHARGE
^C_1206
.001-5%
+16V
4
-
5
+
^C_1206
470pF-50V-5%
N470
R336
10.0K
N445
R337
12.7K
R338
10.0K
NC
3
2
312
^R_0805
^R_0805
^R_0805
{Value}
C126
COMP
COMP
U13:1
2
LM339
R340
392K
^R_0805
+16V
R341
C124
PRI_LO
ES1
ES2
240V,FULL
WAVERECT
EL1
120V,VOLT
DOUBLER
FLIP-FLOP
150K
^R_1206
.001-5%
.1-250V-X
J120
^R_1206
R342
150K
^C_1206
AC-SW
600V-50A
N380
E120B
120V,PAR
RECT DIODES
E240
E120A
U14:2LM556-SMT
C125
.1-50V-10%
N447
L6:2
34
PARALLELWINDING ON
RESONANT INDUCTOR
^C_1206
BR1
2
N421
^R_1206
AC1
PRI_LO
R343
150K
1
+
AC2
3
-
4
N382
N383
N384
^R_0805
PRI_HI
R344
100K
^R_1206
R345
100K
^R_1206
MURS160T3
^D_SMB
N420
.0022-250VAC
0.5-1 MA TO TRIGGER
U15
6
NC
5
4
PRI_LO
N448
^200V-.2A-50NS
N381
XF-BIAS
N117
R376
10.0K
P2P1
XF-PRI
N422
D60
600V TRACE
C127
100PF @ 15KV ESD
100NF @ 15V BYPASS
1
2
3
NC
FROM DC SHUTDOWN,
SHEET 4
AVERAGELIMITING HAS
SEVERAL SECOND TIME
CONSTANTTO REACH
2.4V THRESHOLD,
AVECURRENT 20-25A
D61
^D_SOT-23
R346
20.0K
C132
C133
C122
T1:2
PRI_LO
^R_0805
T1:1
DC-OFF
^R_0805
C136
2200-200V
C137
2200-200V
N370
.0022-250VAC
N426
MURS120T3
S3S4
R375
10.0K
^Q_BJTP_SOT-23
PRI_LO
C135
.1-50V-10%
N450
N449
C131
470-16V
2200-200V
2200-200V
IGBT HEAT SINK
E14
D62
N453
5
D
6
N/C
7
N/C
8
S
U16
TOP 210
+6 V
R348
^C_1206
+16V
R347
2.21K
Q95
3904
^Q_BJTN_SOT-23
N451
PRI_LO
Q99
3906
R374
^R_0805
C
N/C
N/C
S
2.21K
^R_0805
1
2
3
+18V
C138
536
5V NOM
4
3
2
1
^R_0805
N455
U17
NC
NC
PRI_HI
R351
TRANSFORMER
QUIET END
R352
PRI_LO
100-25V-105C
D67
N424
N476
R353
10.0
^R_1206
T1:3
S7S8
ISOL WINDING - 6V
6
5
4
30K-2W
P3P2P1
30K-2W
^D_SOT-23
^D_SOT-23
N428N427
^D_SOT-23
D66
^D_ZEN_SOT-23
^D_SOT-23
R349
R356
PS-OL
SH 4
T2:1
P5P6P7
XF-79
D63
4148
D64
4148
D65
4148
10V-.3W
4148
39.2
^R_1206
N423
10.0
^R_1206
C142
100-25V
N454
^200V-.2A-50NS
^D_SOT-23
V-STBY
TO SH 4
+6 V
N458
+18V
.1-50V-10%
N395
.1-50V-10%
470-63V
470-100V
470-100V
470-63V
MURS160T3
^C_1206
^C_1206
PRI_LO
C164
C165
C166
C167
D86
^D_SMB
U18
1
LO
2
COM
VSS
3
VCC
LIN
4
SD
5
VS
HIN
6
VB9VDD
7
HO
IR2110
USE THRU HOLE,
HIGHER WATTAGE
C168
470-63V
470-63V
470-100V
470-100V
C169
470-100V
470-100V
C170
C171
470-63V
470-63V
14
13
12
11
10
8
C172
C175
C173
C174
470-63V
470-100V
470-100V
470-63V
+HI-RAIL
+MID-RAIL
P1
-MID-RAIL
-HI-RAIL
C185
PRI_LO
+VREF
^C_1206
.1-50V-10%
N398
N397
N399
R360
C181
16
15
14
13
12
11
10
9
7.87K
^R_0805
470pF-50V-5%
N385
C123
R373
C144
.47-400V
5.6-2W
.1-400V
N425
D69
4148
^D_SOT-23
+16V
C139
PRI_LO
N472
C113
N386
12
.0033
100-25V
L6:1
56-2W
XF-79
R372
T2:2
N394
N388
R354
C145
D70
5.6-2W
330p-500V
N387
CE
MUR440
Q96
IRG4PC50U
G
N390
^R_1206
D78
^200V-.2A-50NS
^D_SOT-23
R359
10.0
C155
^C_1206
.1-50V-10%
+16V
C163
N391
R355
5.6-2W
N389
C146
330p-500V
N429
S11
S12
N430
S13
S14
S15
S16
P1
S17
N431
S18
N432
S19
S20
N433
TO TURN-OFF MUTING
SHEET 4 (FAN SPEED)
15V-SW
D71
R350
N434
C147
CE
MUR440
30A-400V
D_TO247AD
15-2W
100pF-500V
30A-400V
Q97
IRG4PC50U
N392
G
D72
30A-400V
D74
15A-200V
D80
15A-200V
D75
15A-200V
D81
15A-200V
D73
30A-400V
^R_1206
D79
^200V-.2A-50NS
^D_SOT-23
N435
D84
N436
N437
N438
D85
D76
R358
10.0
2 BEADS IN PARHI RAIL
1 BEAD LO RAIL
6UH-BEAD
6UH-BEAD
6UH-BEAD
6UH-BEAD
6UH-BEAD
6UH-BEAD
L7
12
L8
12
L9
12
L10
12
L11
12
L12
12
N393
C151
C152
C153
C154
470-63V
470-100V
470-100V
470-63V
C162
C158
C159
C160
C161
+15V
MURS120T3
D68
R357
N456
C143
C148
100-25V
P
39.2
^R_1206
^C_1206
470pF-50V-5%
D82
MURS120T3
D77
MURS120T3
D83
MURS120T3
^D_SMB
C149
100-25V-105C
C150
100-25V-105C
NEW, LO-ESR, 2PL
C156
C157
.1-250V
P1
.1-250V
-15V
U19
VREF
VIN
OUTB
VC
OSC.OUT
GND
OUTA
SHTDWN
DISCHG
COMP8SFT-SRT
SG3525AN
^R_0805
N441
R361
536
^C_1206
+16V
1
-IN
2
+IN
3
SYNC
4
5
CT
6
RT
7
^C_E_ALUM_B
R362
R363
N440
N442
N443
C182
PRI_LO
C183
^C_1206
.1-50V-10%
PRI_LO
N402
N403
^R_0805
N404
C184
1-50V
4.75K
^R_0805
N439
^Q_BJTP_SOT-23
10.0K
^R_0805
6
TRIGGER
5
OUTPUT
4
RESET
3
CONTROL_V
2
THRESHOLD
1
DISCHARGE
^C_1206
470pF-50V-5%
R364
100
PRI_LO
+VREF
+VREF
N400
R365
C116
.1-50V-10%
^C_1206
Q98
3906
COMP
FLIP-FLOP
COMP
N401
N405
15.0K
C186
^R_0805
PRI_LO
U14:1LM556-SMT
^C_1206
470pF-50V-5%
R366
10.0K
D
C
^R_0805
B
DWG NO.
SH-002403-00
5
REVSH
C
SMT-B PKG OK
N452
SIZE FSCM NO.DWG NO.
D
SCALECAD FILE NO.SHEET
NONE
SH-002403-00
plx2402.sch
5OF5
A
REV
C
71
Page 76
87654321
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
REVISION
D
POS STEP
INPUTFILTER
THERMAL
SENSING
LED
DISPLAY
GAIN
POT
LOOP GAIN
FEEDBACK
CLIP
LIMITING
CURRENT
SPLITTER
C
POSITIVE
OUTPUTS
NEGATIVE
OUTPUTS
NEG STEP
SPKR
OUTPUT
CHANNEL A
AUDIO CIRCUITS
INPUT
FILTER
GAIN
POT
BR MONO ROUTING
LED
DISPLAY
THERMAL
SENSING
LOOP GAIN
FEEDBACK
CLIP
LIMITING
CURRENT
SPLITTER
SHEET 2
OP-AMP
SUPPLIES
POWER
SUPPLY
BLEEDERS
EMI
FILTER
INRUSH
RELAY
AC
RECT
MAIN
FILTERS
POS STEP
POSITIVE
OUTPUTS
NEGATIVE
OUTPUTS
NEG STEP
IGBT
SWITCHES
SPKR
OUTPUT
CHANNEL B
AUDIO CIRCUITS
SHEET 3
GATE
DRIVE
D
C
DC FAULT
B
SHUTDOWN
A
2. COMPONENTS WITH VALUE PREFIXED WITH A "^" REPRESENT SMT COMPONENTS.
1. THIS DRAWING USED IN CONJUNCTION WITH ASSEMBLY WP-000541-00.
NOTES: UNLESS OTHERWISE SPECIFIED
87654321
THERMAL
SHUTDOWN
FAN SPEED
TO MUTE
CONTROL
SUPPORT AND
PROTECTION
CIRCUITS
SHEET 4
SHUTDOWN
TRIGGERS
RELAY
CONTROL
BIAS
SUPPLY
OVERCURRENT
DETECTION
HIGH FREQ
TRANSFORMER
ISOLATED
HIGH FREQ
RECTIFIERS,
FILTER CAPS
WP-000541-00
NEXT ASSYUSED ON
APPLICATION
PLX 3002
SWITCHING
OSCILLATOR
ITEM NO.QTYPART NO.
UNLESS OTHERWISE SPECIFIED
DIMENSIONS ARE IN INCHES.
DIMENSIONS PER ANSI Y14.5-1982
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
D
J1
N1
J3:3
3
R
RING
J3:2
TIP
T
S
J3:1
1
N2
J3:4
4
2
3
N3
1
J2
SW1:5
SW1:6
DIP-10
DIP-10
515
616
+13IN
N23
N22
-XLR_B+XLR_B
INPUTS IN PARALLEL
C
-SH3
N24
N28
R1
1.00K
^R_1206
N29
PARALLEL
INPUT SW.
STATUSLED
YEL
LD1
N30
B
LED-SIGNAL DISPLAY
N110
LD2
GRN
Q1
3906
^Q_BJTP_SOT-23
N112
Q2
LD3
GRN
3906
^Q_BJTP_SOT-23
N114
Q3
LD4
GRN
3906
^Q_BJTP_SOT-23
^Q_BJTP_SOT-23
A
CLIP
RED
LD5
87654321
SH 4, EURO-INPUTS
-IN_CH-A +IN_CH-A-IN_DPA
N4
J4:3
^R_0805
3
J4:2
2
J4:1
1
J4:4
4
A-1 GND
A-4, GND
A-2 +A
A-3 -A
C195
A-20, +13V
N31
CWCCW
W
GAIN
N33
J4:20
N32
^R_0805
10
414
N25
20
J5:12
12
J5:4
4
J5:3
3
J5:1
1
J5:2
2
.001-5%
^C_1206
SW1:4
DIP-10
J3:20
20
VR2
10K-THRU-PCB
N113
R3
4.75K
^R_0805
Q4
3906
C4
J5:5
5
N119
J5:6
6
INPUT AND FILTER SECTION, CH A
N8
C5
100pF-50V-5%
C3
4148
N34
R10
SH 4
A1
N118
10-35V
D2
N15
8
4.75K
SH 4
+14VIC
N116
^C_0805
R12
5.60K-.1%
+14VIC
SIGNAL
POLARITY
MC33078-SMT
84
+
-
-14VIC
U1:1
INVERTED
1
N11
N102
3
2
N9
R13
5.60K-.1%
C6
100pF-50V-5%
^C_0805
C7
47-10NP-10%
2 POLE CASCADED ROLLOFF
-0.15dB, 20Hz. -0.4dB, 10Hz.
R-parallel, 7.5K, 10K, 4.7K, = 2.24K
7.50K
^R_0805
R14
12.7K
^R_0805
^R_0805
R11
4.75K
^R_0805
N37
N36
75
8
^U_LM13600
J5:7
7
A1
J4:9
J3:9
N19
J4:6
6
A1
R15
100pF-50V-5%
3
+
2
-
^R_0805
BR MONO FEED, SH 3
U3:1
LM13600M
N130
J6:7
.1-5%
^R_0805
9
9
A-6, GND
^C_0805
R16
12.7K
1
N121
7
C8
R17
4.75K
A-9, LF SIG
SW1:3
DIP-10
C9
CH_A_SIG
J3:6
U2:1
NE5532
116
^R_0805
N131
1
NEG INPUT
R5
75
N5
N6
A1
N7
C1
R9
5.60K-.1%
^C_1206
470pF-50V-5%
C2
N14
+IN_DPA
J4:10
^C_1206
470pF-50V-5%
R8
5.60K-.1%
DP-PAR-F
10
POS INPUT
R6
75
DATAPORTCONNECTED TO INPUT
AS USUAL TO MINIMIZE CROSSTALK
WHEN USING REGULAR INPUTS
AMP LOOP GAIN -- 32DB REVISION
USE SAME VALUEAS PLC-2
NTCBUS
N46
D3
N45
C15
100-25V
R36
R37
N42
+13VCL
R33
100K
^R_0805
N136
R34
1.50K
^R_0805
N133
Q8
3904
R35
1.50K
^R_0805
4148
^D_SOT-23
R41
1.50K
^R_0805
12.7K
^R_0805
475
^R_0805
R38
7.50K
N135
^Q_BJTP_SOT-23
R39
1.50K
P
N230
R101
1.50K
^R_0805
VR43
N44
N43
D4
D5
C17
^C_1206
^R_0805
470pF-50V-5%
Q12
3906
N137
R42
1.00K
^R_0805
^R_0805
CLIP-LIMIT
PROCESSOR
N47
TH-SUBC-A
N49
250
CWCCW
W
4148
^D_SOT-23
C18
4148
^D_SOT-23
N89
-15NTC
R106
12.7K
^R_0805
Q13
3904
^Q_BJTN_SOT-23
^R_1206
R44
383
R47
N48
R45
^C_0805
100pF-50V-5%
R46
12.7K
^R_0805
N87
4148
^D_SOT-23
DATAPORT, SH 4, CLIP A
N138
2.21K
^R_0805
P
POS STEP DRIVER
N51
+15NTC
12.7K
^R_0805
N50
N88
C20
.0027
^C_0805
R48
2.00K
^R_0805
MUTE_HI
D89
SH 4
PROT
SH 3
CLIP_A
C19
^C_1206
.1-50V-10%
R49
^R_1206
POSREF
N54
^R_1206
47-50V
^Q_BJTP_SOT-23
R51
P
FULL MUTE, 5.7V
N90
SEE SH 4
P
R53
47-50V
^Q_BJTN_SOT-23
R50
30.1K
^R_1206
30.1K
^R_1206
R52
150K
R54
150K
C21
Q14
3906
100K
^R_1206
MUTE+
^Q_BJTN_SOT-23
P
100K
^R_1206
C22
Q15
3904
N98
DC_SENSE
N139
R55
4.75K
^R_0805
R56
4.75K
^R_0805
R59
R60
N64
300V-.2A
N91
R65
N92
300V-.2A
^Q_BJTP_SOT-23
N97
R61
R62
SH 4
NEGREF
N140
R57
150K
^R_1206
R58
150K
^R_1206
C179
Q16
12.7K
Q17
P
N141
D6
N53
10V-1N4740A
.36W at full clip
4.75K
^R_0805
39.2K
^R_0805
+15NTC
.1-50V
P
^R_0805
C180
-15NTC
N96
39.2K
^R_0805
4.75K
^R_0805
N143
N56
3.9V
^R_0805
N52
N55
D7
C23
.0027
Q24
3906
^Q_BJTP_SOT-23
N65
R381
100
^C_1206
^R_0805
.1-50V
^C_1206
R382
100
^R_0805
^Q_BJTP_SOT-23
Q25
3904
^Q_BJTN_SOT-23
C24
.0027
R2
47.5K
^R_0805
R63
4.75K
^R_0805
R64
4.75K
^R_0805
N57
R66
R78
392K
U4
1
GND
2
3
4
V-
^LM311-SMT
BAL/STR
8
V+
7
6
5
BAL
N58
POS OUTPUT SECTION
75
75
R72
R73
N84
^R_0805
^R_0805
N95
R74
R75
100K
N78
N93
N100
2.21K
^R_0805
^R_0805
^D_SOT-23
^R_1206
C25
C26
100K
^R_1206
2.21K
^R_0805
^D_SOT-23
R76
39.2K
D9
680pF
470pF
N101
^D_SOT-23
R77
39.2K
^R_0805
274
R67
^R_0805
^C_0805
N66
Q18
3904
^Q_BJTN_SOT-23
N477
N83
Q20
R70
R71
N478
2SA1837
Q23
3906
N99
^C_0805
274
R68
^R_0805
N67
Q19
2SC4793
2N3904
Q21
2N3906
N94
Q22
NEG OUTPUT SECTION
N396
C187
47pF-50V-5%
^C_0805
R69
392K
^R_0805
N144
U5
1
GND
2
3
4
V-
BAL/STR
8
V+
7
6
5
BAL
^LM311-SMT
NEG STEP DRIVER
5.90K
R79
3.01K
^R_0805
4148
N79
^D_SOT-23
D10
200V-.2A-50NS
^C_0805
N85
^C_1206
200V-.2A-50NS
^D_SOT-23
D11
D12
4148
D8
4148
N145
C177
^R_0805
^D_SOT-23
R81
N68
N70
D14
4148
4148
^D_SOT-23
^D_SOT-23
SPKR_BUS_A
C27
.022
R80
5.6-2W
D13
4148
^D_SOT-23
MJE15032
R82
.1-50V-10%
C30
47pF-50V-5%
^C_0805
D15
4148
N59
200
^R_0805
Q26
MJE15033
D16
Q30
3904
^Q_BJTN_SOT-23
Q31
3906
^Q_BJTP_SOT-23
R88
R85
15-2W
2SA1302
N71
Q28
N77
R91
N72
2SA1302
L-Z_A1
N81
N60
R96
R97
R94
Q34
I-MON SH 4
12
2UH-14GA-AIR
10-35V
3.9K-2W
R102
N73
2SA1302
Q36
L1
C31
R104
R105
N80
R98
5.6-2W
C28
N466
R367
15-2W
R87
15-2W
PP1
Q27
N104
Q29
N102
2SC3281
N103
200
^R_0805
R89
R86
15-2W
N146
R83
5.90K
^R_0805
Q32
D17
3904
4148
R84
2.21K
^R_0805
^Q_BJTN_SOT-23
Q33
3906
^Q_BJTP_SOT-23
^D_SOT-23
^C_1206
.1-250V
R92
R90
2SC3281
N105
R95
47pF-50V-5%
N86
R93
15-2W
15-2W
PWR-GND, TO SUPPLY CT
Q35
Q37
2SC3281
N106
R99
R103
C29
^C_0805
R100
47.5
N147
^R_0805
N61
P
R107
R108
N63
R110
47.5
^R_0805
12.7K
^R_0805
3.9K-2W
R111
N74
2SA1302
Q39
D
Q40
2SC3281
N107
R112
N148
N82
Q38
RFZ44
D18
C32
R113
R114
N142
N62
4148
100-25V
.47-2W
SPKR-A
E10A
.47-2W
V-NEGSTEP
-HI-RAIL
RFZ44
^D_SOT-23
8PL
1.5-2W
D19
E9A
D20
1.5-2W
8PL
Q41
R115
1N5402
E9B
E10B
1N5402
R116
15A-200V
D22
15A-200V
N75
N461
N108
D21
+HI-RAIL
+MID-RAIL
N76
C34
.1-250V
N459
C129
J7
.1-250V
E9C
1+
1-
2+
2-
EMI_G
BR-POS
FROM CH B
SHEET 3
JACK-SPEAKON
BR-NEG
N462
E10C
C35
.1-250V
N109
-MID-RAIL
SIZE FSCM NO.DWG NO.
D
SCALECAD FILE NO.SHEET
NONE
plx3002.sch
SH-000541-00
2OF5
D
C
B
DWG NO.
SH-000541-00
2
REVSH
C
A
REV
C
73
Page 78
87654321
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
D
OPAMP POWER SUPPLIES
C
BR-ON
SH 3
D48
4148
^D_SOT-23
R240
N332
^Q_BJTP_SOT-23
B
POWER LED
ON DISPLAYPCB
A
47-10NP-10%
N349
GRN
N350
N331
DC_SENSE
2.21K
^R_0805
SH 2, 3
R242
20.0K
^R_0805
P
Q87
3906
^D_SOT-23
C71
N333
^D_SOT-23
DC MUTING
J6:14
J5:14
14
LD11
J6:16
J5:16
16
D50
4148
D49
4148
14
16
N338
-DC THRESH, -4V
N339
+DC THRESH 4V
R241
12.7K
^R_0805
N348
R243
R244
R245
N330
D
N366
DP-PAR-F
SH 2
DP-BR-F
SH 3
D
N291
SEE SH 2
TH-SUBC-A
N326
+13VCL
D
N358
SEE SH 3
TH-SUBC-B
I-MON CH B
(WITH SEP.CH B
THERMAL SUBCODE)
N367
D
V-MON CH A
INJECT V-DC
POST OPAMP,
NO GAIN SCALING
D
I-MON CH A
(WITH SEPARATECH A
THERMAL SUBCODE)
V-MON CH B
(PWR-SUPPLY-ON
SUBCODE: .8-1.3V)
SCALE 13V TO 1V NOM
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION WHICH IS THE PROPERTY
OF QSC AUDIO PRODUCTS, THAT MAYNOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
J19
N368
1
F1
2
AC-HI
D
120, 240V
AC-LO
25A-125V
N371
J20
1
2
C
^Q_BJTN_SOT-23
D58
^D_SMB
MURS160T3
R321
N416
N417
R322
C107
.1-400V
B
SET NOM PEAK AT13V, 120VAC
DECLINES ABOUT 30% EVERY 35 MS
REACHES 8.7V IN 40 MS, (2 AC CYCLES)
R323
A
87654321
487K
487K
39.2K
X-CAPS, 3 PL
N372
^R_1206
^R_1206
N418
^R_0805
C108
L3:1
C110
1.0 250VAC
L3:2
+18V
D59
Q92
3904
.0027
^C_0805
R325
PRI_LO
LINE FILTER SHIELD
13
C112
1.0 250VAC
24
4148
^D_SOT-23
RELAY25MA
N375
C115
C118
.0033 250VAC
.0033 250VAC
+VREF
N373
R327
4.75K
N406
Q93
R326
487K
3904
N411
^R_1206
^Q_BJTN_SOT-23
PRI_LO
NOM BUS VOLTAGE340V (120-240VAC)
MIN BUS VOLTAGE200-220V (75-150 VAC)
^R_1206
N410N409
8
-
U13:3
14
9
+
LM339
974K - 24.9K RES DIVIDER
340V NOM BUS = 8.67V
200V MIN BUS = 5.1V UV
24.9K
C109
.0027
^R_0805
^C_0805
C128
.0027
^C_0805
750K, X-CAP DISCHARGE
TO MEET IEC STANDARD:
BECAUSE X-CAP EXCEEDS 0.1UF
MUST DISCHARGE X-CAP TO
34 V WITHIN 2 SECONDS.
230V X 1.41 = 325V ->34 V
FOR C = 1.5UF,R < 628K, 0.1W
L4:1
N376N374N369
13
C117
.47-250VAC
N377
24
L4:2
CH-GND
STUD
E11
N309
RELAYSTARTS OFF LOW. 5V LINE
SETTLES HIGH BEFORE 16V > 8V,
BECAUSE TRIG IS LOW UP TO 10V