Leisure Craft Procon 1000-P, Procon 1500-P, Procon 1250-P, Procon 1800-P, Procon 750-P Service manual

...

Index

Technical specifications, transistor packages, Procon 400p test procedures.2 Procon 750p, Procon 1000p test procedures.3

Power Amplifiers

procon plus

Procon 1250p, Procon 1500p test procedures. Procon 1800p, Procon 2200p test procedures. 5

Procon 400p schematic.

7 Procon 750p schematic. 8

Procon 1000p schematic.

9 Procon 1250p schematic. 10

Procon 1500p schematic.

11 Procon 1800p schematic. 12 Procon 2200p schematic. 13 Spare part list.

service manual

schematic diagrams

Notice

Service must be carried out by qualified personnel only. Any tampering carried out by unqualified personnel during the guarantee period

✔

will forfeit the right to guarantee. For a correct operation of the instrument, after having switched off, be careful to wait at least 3 seconds before switching on again.

✔

To improve the device's specifications, the schematic diagrams may be subject to change without prior notice.

✔

All components marked by this symbol have special safety characteristics, when replacing any of these components use only manufacturer's specified parts. The (µ) micro symbol of capacitance value is substituted by U.

✔

The (

✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔

✒

Ω) omega symbol of resistance value is substituted by E.

The electrolytic capacitors are 25Vdc rated voltage unless otherwise specified. All resistors are 1/8W unless otherwise specified. All switches shown in the "OFF" position. All DC voltages measured to ground with a voltmeter 20KOhm/V.

Soldering point. Male connector.

Female connector.

M/F faston connector.

ATTENTION Observe precautions when handling electrostatic sensitive devices.

Supply voltage. Logic supply ground. Test point.

Flag joined with one or more flags with the same signal name inscribed.

Analog supply ground.

Chassis ground. Earth ground.

GENERALMUSIC S.p.A. Sales Division: 47842 S.Giovanni in Marignano (RN) ITALY - Via delle Rose, 12

CODE: 270312

Phone +39(0)541/959511 - Fax +39(0)541/957404 - Internet: www.generalmusic.com

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PROCON PLUS SERIES • TECHNICAL SPECIFICATIONS

POWER SPECIFICATIONS

EIA output power 1kHz, THD maximum 1% Both channels

ELECTRICAL SPECIFICATIONS

INPUT SENSITIVITY

INPUT IMPEDANCE

FREQUENCY RESPONSE

VOLTAGE GAIN

SLEW RATE

DAMPING FACTOR

CROSSTALK

S/N ratio Harmonic distortion THD Intermodulation distortion SMPTE

GENERAL SPECIFICATIONS

PROTECTIONS

CONTROLS

INDICATORS

CONNECTORS

POWER SUPPLY DIMENSIONS WEIGHT

8 ohm 4 ohm

8 ohm BRIDGED

OUT

mm (WxHxD)

kg 13 15 18 19.5 21 23.5 25

400P 750P 1000P 1250P 1500P 1800P 2200P

125+125 200+200

400

215+215 375+375

750

300+300 550+550

1100

375+375 625+625

1250

450+450 750+750

1500

550+550 900+900

1800

400P 750P 1000P 1250P 1500P 1800P 2200P

0dB (0.775V)

10 kOhms (balanced)

10÷50000 Hz (-0.5dB)

32dB 33dB 35dB 36dB 37dB 37dB 39dB

22 V/ms

>400:1 @ 1kHz, 8Ohms

-82 dB (1KHz)

-100 dB

<0.1% (ref 20Hz -20KHz)

<0.1% (SMPTE method, 60Hz & 7kHz, 4:1 ratio)

400P 750P 1000P 1250P 1500P 1800P 2200P

Power transformer thermal protection

Short circuit protection Sensor for current on outputs CLIP Limiter on each channel

Soft-start circuit (1000P to 2200P)

ON/OFF switch

21-detect input level control for each channel

MODE selector

SHIELD selector

POWER ON: 1 red LED

BRIDGE: 1 red LED

PROTECT: 1 red LED

LEVEL: 2 x 5-LED meters

LIMIT: 1 red LED

2 x BINDING POST + 1 SPEAKON for each channel (400-1500)

1 SPEAKON for each channel + 1 SPEAKON for BRIDGE output (1800-2200)

483x88x366 483x88x428

1 XLR-F + 1 JACK in parallel for each channel

see label on the unit

483x88x456

650+650

1100+1100

2200

PROCON400p - Test procedures

PRECAUTION

• To prevent short circuit during any test, the oscilloscope must be EARTH INSULATED, this occurs because some test require to connect its probe to the ampliﬁ er output, non-compliance may cause damages to oscilloscope inputs circuitry.

• Before removing or installing any modules and connectors, disconnect the ampliﬁ er from AC MAINS and measure the DC supply voltages across each of the power supply capacitors. If your measurement on any of the caps is greater than 10Vdc, connect a 100E 60W resistor across the applicable caps to discharge them for your safety. Remember to remove the discharge resistor immediately after discharging caps. Do not power up the ampliﬁ er with the discharge resistor connected.

• Do not check the ampliﬁ er with the speakers connected use the appropriate load resistors only.

• BE CAREFUL increasing the Variac you must not exceed the nominal mains voltage plus its tolerance (see speciﬁ cations) any upper voltage can be cause of damage.

VISUAL CHECK

• Use compressed air to clear dust in the ampliﬁ er chassis.

• Before proceed to supply the ampliﬁ er check visually the internal assembly, if appears an evident damage ﬁ nd the most possible reasons that cause it.

• Check the wiring cables for possible interruptions or shorts.

• If the damage has burnt a printed circuit board don’t try to repair it, replace with a new one.

TESTING GEAR

• Audio Generator

• Dual Trace Oscilloscope

• Digital Multimeter

• 4E 300W, 8E 450W, 100E 60W resistors

• Variac

• Digital Thermometer (not indispensable)

SETUP

• Connect the Variac between the Mains and the ampliﬁ er and set it at zero voltage.

• Turn full counter-clockwise the LEVEL potentiometers.

• Connect the audio generator to the channel inputs and set it to 1KHz 775mVrms (0dBu) sinusoidal signal.

• Connect the two scope traces to the ampliﬁ er outputs, before the relay, and set them in DC at 20V/div. 2mS/div.

SUPPLY CHECK

• Verify with the Multimeter the insulation between the heatsinks and all transistor collectors mounted on them; placing the multimeter tips between the screw heads and the collector pins you can exclude an erroneus reading due to the insulation of the heatsink anodization.

• Verify with the Multimeter the NTC (RT1) and R1 paralleled resistor value, it must be about 1080ohm (at 25°c).

• Disconnect the ampliﬁ er module supplies of each channel (red and yellow wires).

• Set the Variac to the nominal mains voltage, turn on the Ampliﬁ er, then check with the Multimeter the AC supply voltages:

F1-F2 = 29±2Vac. RED secondary wires = 87±9Vac.

• Re-set the Variac at zero voltage, turn off the ampliﬁ er and reconnect the supplies at each ampliﬁ er module.

• Set up the Variac slowly monitoring the oscilloscope screen, it should display no signal; if you notice a DC voltage or a protection trips check the ampliﬁ er as suggested in the ADVICES.

• As soon as the +12VF supply circuit reaches its nominal value, all cooling fans run at their minimum and the speaker output relais (J201-202) switch.

• When the Variac ac voltage reaches the nominal voltage verify the DC supplies as follow:

• If one or more voltages don’t correspond, check the rectiﬁ ers, capacitors and transformers disconnecting them from cir cuit ry.

CHANNEL CHECK

• Be sure you have dis con nect ed the load re sis tor.

• Increasing the input sig nal also the output signal raise ac cord ing ly, it must be sym met ri cal without vis i ble dis tor tion or os cil la tion as shown in figure (note: the ﬁ g ure is rep re sent a tive don`t re fer to the levels dis played). If there is a dis tor tion read the sec tion ADVICES.

• When the input sig nal exceeds -20dBu (20Vpp on output) the fans turn at their max i mum speed.

• Firstly you must check the channel without load, afterwards you must repeat the check with the loads attached, the following table reports the approx. maximum level obtainable with this amp:

out level in level no load 113Vpp +1.5dBu 1CH 4E 91Vpp -0.2dBu 2CH 4E 82Vpp -2.0dBu Bridge 8E 161Vpp -2.3dBu

LEVEL METER ADJUSTMENT

• Check if the clip led lights at -2dBu on input (~80Vpp on output), if necessary adjust the trimmers W301/2 on dis play board.

OFFSET ADJUSTMENT

• Set the input level at minimum (no signal), the output dc offset voltage must be within range ±20mV, if necessary adjust the VR201 trimmer (for each channel) to be within this range.

BIAS ADJUSTMENT

• No bias adjustment is necessary for this ampliﬁ er circuitry.

ADVICES

• If you have determinate that the problem is a short on a rail, you must check the output transistors.

• To determine which transistor devices are bad, use a soldering iron to lift one leg of each emitter pin and measure the resistance across emitter and collector of each device. Unsolder and lift one leg of each base pin and check the base-collector resistance. Replace any device that measure as a short.

• If all the transistors are OK, unsolder and lift one leg of each diode and check them.

• Check the circuit board for open foil traces.

• Use the Multimeter to check the resistors, particularly the base and emitter resistors of damaged transistor.

• If the input sinewave appears to be distorted during the negative cycle, you can assume that the problem is located somewhere in the circuitry of the positive rail.

• If the positive cycle appears distorted, you can assume that the problem is in the circuitry of the negative rail.

• The dc voltages printed on the schematics are measured with the ampliﬁ er in steady state without input signal and nominal mains voltage supply, it can be useful to localize a damage.

+VCC = +59±6Vdc

-VCC = -59±6Vdc U101 pin 8 = +12±0.5Vdc U101 pin 4 = -12±0.5Vdc U403 pin 3 = +12±0.5Vdc

PROCON750p - Test procedures

PRECAUTION

• Before removing or installing any modules and connectors, disconnect the ampliﬁ er from AC MAINS and measure the DC supply voltages across each of the power supply capacitors. If your measurement on any of the caps is greater than 10Vdc, connect a 100E 70W resistor across the applicable caps to discharge them for your safety. Remember to remove the discharge resistor immediately after discharging caps. Do not power up the ampliﬁ er with the discharge resistor connected.

• Do not check the ampliﬁ er with the speakers connected use the appropriate load resistors only.

• BE CAREFUL increasing the Variac you must not exceed the nominal mains voltage plus its tolerance (see speciﬁ cations) any upper voltage can be cause of damage.

VISUAL CHECK

• Use compressed air to clear dust in the ampliﬁ er chassis.

• Before proceed to supply the ampliﬁ er check visually the internal assembly, if appears an evident damage ﬁ nd the most possible reasons that cause it.

• Check the wiring cables for possible interruptions or shorts.

• If the damage has burnt a printed circuit board don’t try to repair it, replace with a new one.

TESTING GEAR

• Audio Generator

• Dual Trace Oscilloscope

• Digital Multimeter

• 4E 450W, 8E 800W, 100E 70W resistors

• Variac

• Digital Thermometer (not indispensable)

SETUP

• Connect the Variac between the Mains and the ampliﬁ er and set it at zero voltage.

• Turn full counter-clockwise the LEVEL potentiometers.

• Connect the audio generator to the channel inputs and set it to 1KHz 775mVrms (0dBu) sinusoidal signal.

• Connect the two scope traces to the ampliﬁ er outputs, before the relay, and set them in DC at 20V/div. 2mS/div.

SUPPLY CHECK

• Verify with the Multimeter the NTC (RT1) and R1 paralleled resistor value, it must be about 1080ohm (at 25°c).

• Disconnect the ampliﬁ er module supplies of each channel (red and yellow wires).

• Set the Variac to the nominal mains voltage, turn on the Ampliﬁ er, then check with the Multimeter the AC supply voltages:

F1-F2 = 29±2Vac. RED secondary wires = 106±10Vac.

• Re-set the Variac at zero voltage, turn off the ampliﬁ er and reconnect the supplies at each ampliﬁ er module.

• Set up the Variac slowly monitoring the oscilloscope screen, it should display no signal; if you notice a DC voltage or a protection trips check the ampliﬁ er as suggested in the ADVICES.

• As soon as the +12VF supply circuit reaches its nominal value, all cooling fans run at their minimum and the speaker output relais (J201-202) switch.

• When the Variac ac voltage reaches the nominal voltage verify the DC supplies as follow:

+VCC = +72±7Vdc

-VCC = -72±7Vdc U101 pin 8 = +12±0.5Vdc U101 pin 4 = -12±0.5Vdc U403 pin 3 = +12±0.5Vdc

• If one or more voltages don’t correspond, check the rectiﬁ ers, capacitors and transformers disconnecting them from cir cuit ry.

CHANNEL CHECK

• Be sure you have dis con nect ed the load re sis tor.

• When the input sig nal exceeds -20dBu (20Vpp on output) the fans turn at their max i mum speed.

• Firstly you must check the channel without load, afterwards you must repeat the check with the loads attached, the following table reports the approx. maximum level obtainable with this amp:

out level in level no load 139Vpp +3.0dBu 1CH 4E 117Vpp +1.5dBu 2CH 4E 109Vpp +0.9dBu Bridge 8E 214Vpp +0.7dBu

LEVEL METER ADJUSTMENT

• Check if the clip led lights at -1dBu on input (~90Vpp on output), if necessary adjust the trimmers W301/2 on dis play board.

OFFSET ADJUSTMENT

• Set the input level at minimum (no signal), the output dc offset voltage must be within range ±20mV, if necessary adjust the VR201 trimmer (for each channel) to be within this range.

BIAS ADJUSTMENT

• No bias adjustment is necessary for this ampliﬁ er circuitry.

ADVICES

• If you have determinate that the problem is a short on a rail, you must check the output transistors.

• If all the transistors are OK, unsolder and lift one leg of each diode and check them.

• Check the circuit board for open foil traces.

• Use the Multimeter to check the resistors, particularly the base and emitter resistors of damaged transistor.

• If the input sinewave appears to be distorted during the negative cycle, you can assume that the problem is located somewhere in the circuitry of the positive rail.

• If the positive cycle appears distorted, you can assume that the problem is in the circuitry of the negative rail.

• The dc voltages printed on the schematics are measured with the ampliﬁ er in steady state without input signal and nominal mains voltage supply, it can be useful to localize a damage.

PROCON1000p - Test procedures

PRECAUTION

• Before removing or installing any modules and connectors, disconnect the ampliﬁ er from AC MAINS and measure the DC supply voltages across each of the power supply capacitors. If your measurement on any of the caps is greater than 10Vdc, connect a 100E 80W resistor across the applicable caps to discharge them for your safety. Remember to remove the discharge resistor immediately after discharging caps. Do not power up the ampliﬁ er with the discharge resistor connected.

• Do not check the ampliﬁ er with the speakers connected use the appropriate load resistors only.

• BE CAREFUL increasing the Variac you must not exceed the nominal mains voltage plus its tolerance (see speciﬁ cations) any upper voltage can be cause of damage.

VISUAL CHECK

• Use compressed air to clear dust in the ampliﬁ er chassis.

• Before proceed to supply the ampliﬁ er check visually the internal assembly, if appears an evident damage ﬁ nd the most possible reasons that cause it.

• Check the wiring cables for possible interruptions or shorts.

• If the damage has burnt a printed circuit board don’t try to repair it, replace with a new one.

TESTING GEAR

• Audio Generator

• Dual Trace Oscilloscope

• Digital Multimeter

• 4E 700W, 8E 1100W, 100E 80W resistors

• Variac

• Digital Thermometer (not indispensable)

SETUP

• Connect the Variac between the Mains and the ampliﬁ er and set it at zero voltage.

• Turn full counter-clockwise the LEVEL potentiometers.

• Connect the audio generator to the channel inputs and set it to 1KHz 775mVrms (0dBu) sinusoidal signal.

• Connect the two scope traces to the ampliﬁ er outputs, before the relay, and set them in DC at 50V/div. 2mS/div.

SUPPLY CHECK

• Verify with the Multimeter the NTC (RT1) and R1 paralleled resistor value, it must be about 7Kohm (at 25°c).

• Disconnect the ampliﬁ er module supplies of each channel (red and yellow wires).

• Set the Variac to the nominal mains voltage, turn on the Ampliﬁ er, then check with the Multimeter the AC supply voltages:

F1-F2 = 29±2Vac. RED secondary wires = 125±6Vac.

• Re-set the Variac at zero voltage, turn off the ampliﬁ er and reconnect the supplies at each ampliﬁ er module.

• Set up the Variac slowly monitoring the oscilloscope screen, it should display no signal; if you notice a DC voltage or a protection trips check the ampliﬁ er as suggested in the ADVICES.

• As soon as the +12VF supply circuit reaches its nominal value, all cooling fans run at their minimum and the speaker output relais (J201-202) switch.

• When the Variac ac voltage reaches the nominal voltage verify the DC supplies as follow:

+VCC = +82±5Vdc

-VCC = -82±5Vdc U501 pin 8 = +12±0.5Vdc U501 pin 4 = -12±0.5Vdc U403 pin 3 = +12.5±0.5Vdc

• If one or more voltages don’t correspond, check the rectiﬁ ers, capacitors and transformers disconnecting them from cir cuit ry.

CHANNEL CHECK

• Be sure you have dis con nect ed the load re sis tor.

• Increasing the input sig nal also the output signal raise ac cord ing ly, it must be sym met ri cal without vis i ble dis tor tion or os cil la tion as shown in ﬁ gure (note: the fig ure is rep re sent a tive don`t re fer to the levels dis played). If there is a dis tor tion read the sec tion ADVICES.

• When the input sig nal exceeds -20dBu (24Vpp on output) the fans turn at their max i mum speed.

• Firstly you must check the channel without load, afterwards you must repeat the check with the loads attached, the following table reports the approx. maximum level obtainable with this amp:

out level in level no load 162Vpp +2.0dBu 1CH 4E 141Vpp +1.7dBu 2CH 4E 131Vpp +1.0dBu Bridge 8E 258Vpp +0.5dBu

LEVEL METER ADJUSTMENT

• Check if the clip led lights at -2dBu on input (~150Vpp on output), if necessary adjust the trimmers W301/2 on dis play board.

OFFSET ADJUSTMENT

• Set the input level at minimum (no signal), the output dc offset voltage must be within range ±20mV, if necessary adjust the VR201 trimmer (for each channel) to be within this range.

BIAS ADJUSTMENT

• No bias adjustment is necessary for this ampliﬁ er circuitry; in any case the ampliﬁ er has the possibility to adjust it if necessary. To check properly the bias proceed as follows:

• Using a sinusoidal signal (1KHz or more) and the 4E load attached, wait till the heatsink temperature reaches about 60°c.

• Turn down the signal at the smallest intensity you can read on your oscilloscope trace connected at the ampliﬁ er output.

• Zoom in the crossing region using the amplitude, timebase and trigger controls of your oscilloscope. If you see a distortion, try to eliminate it adjusting the VR202 trimmer.

• Finally, set the input level at minimum and verify with the multimeter attached across an emitter resistance (p.e. R232) that the dc voltage doesn`t exceed 10mV.

ADVICES

• If you have determinate that the problem is a short on a rail, you must check the output transistors.

• If all the transistors are OK, unsolder and lift one leg of each diode and check them.

• Check the circuit board for open foil traces.

• Use the Multimeter to check the resistors, particularly the base and emitter resistors of damaged transistor.

• If the input sinewave appears to be distorted during the negative cycle, you can assume that the problem is located somewhere in the circuitry of the positive rail.

• If the positive cycle appears distorted, you can assume that the problem is in the circuitry of the negative rail.

• The dc voltages printed on the schematics are measured with the ampliﬁ er in steady state without input signal and nominal mains voltage supply, it can be useful to localize a damage.

PROCON1250p - Test procedures

PRECAUTION

• Before removing or installing any modules and connectors, disconnect the ampliﬁ er from AC MAINS and measure the DC supply voltages across each of the power supply capacitors. If your measurement on any of the caps is greater than 10Vdc, connect a 100E 90W resistor across the applicable caps to discharge them for your safety. Remember to remove the discharge resistor immediately after discharging caps. Do not power up the ampliﬁ er with the discharge resistor connected.

• Do not check the ampliﬁ er with the speakers connected use the appropriate load resistors only.

• BE CAREFUL increasing the Variac you must not exceed the nominal mains voltage plus its tolerance (see speciﬁ cations) any upper voltage can be cause of damage.

VISUAL CHECK

• Use compressed air to clear dust in the ampliﬁ er chassis.

• Before proceed to supply the ampliﬁ er check visually the internal assembly, if appears an evident damage ﬁ nd the most possible reasons that cause it.

• Check the wiring cables for possible interruptions or shorts.

• If the damage has burnt a printed circuit board don’t try to repair it, replace with a new one.

TESTING GEAR

• Audio Generator

• Dual Trace Oscilloscope

• Digital Multimeter

• 4E 800W, 8E 1300W, 100E 90W resistors

• Variac

• Digital Thermometer (not indispensable)

SETUP

• Connect the Variac between the Mains and the ampliﬁ er and set it at zero voltage.

• Turn full counter-clockwise the LEVEL potentiometers.

• Connect the audio generator to the channel inputs and set it to 1KHz 775mVrms (0dBu) sinusoidal signal.

• Connect the two scope traces to the ampliﬁ er outputs, before the relay, and set them in DC at 50V/div. 2mS/div.

SUPPLY CHECK

• Verify with the Multimeter the NTC (RT1) and R1 paralleled resistor value, it must be about 7Kohm (at 25°c).

• Disconnect the ampliﬁ er module supplies of each channel (red and yellow wires).

• Set the Variac to the nominal mains voltage, turn on the Ampliﬁ er, then check with the Multimeter the AC supply voltages:

F1-F2 = 29±2Vac. RED secondary wires = 137±7Vac.

• Re-set the Variac at zero voltage, turn off the ampliﬁ er and reconnect the supplies at each ampliﬁ er module.

• Set up the Variac slowly monitoring the oscilloscope screen, it should display no signal; if you notice a DC voltage or a protection trips check the ampliﬁ er as suggested in the ADVICES.

• As soon as the +12VF supply circuit reaches its nominal value, all cooling fans run at their minimum and the speaker output relais (J201-202) switch.

• When the Variac ac voltage reaches the nominal voltage verify the DC supplies as follow:

+VCC = +92±6Vdc

-VCC = -92±6Vdc U501 pin 8 = +12±0.5Vdc U501 pin 4 = -12±0.5Vdc U403 pin 3 = +12.5±0.5Vdc

• If one or more voltages don’t correspond, check the rectiﬁ ers, capacitors and transformers disconnecting them from cir cuit ry.

CHANNEL CHECK

• Be sure you have dis con nect ed the load re sis tor.

• When the input sig nal exceeds -20dBu (24Vpp on output) the fans turn at their max i mum speed.

• Firstly you must check the channel without load, afterwards you must repeat the check with the loads attached, the following table reports the approx. maximum level obtainable with this amp:

out level in level no load 178Vpp +1.0dBu 1CH 4E 154Vpp +0.8dBu 2CH 4E 141Vpp +0.0dBu Bridge 8E 278Vpp -0.5dBu

LEVEL METER ADJUSTMENT

• Check if the clip led lights at -2dBu on input (~130Vpp on output), if necessary adjust the trimmers W301/2 on dis play board.

OFFSET ADJUSTMENT

• Set the input level at minimum (no signal), the output dc offset voltage must be within range ±20mV, if necessary adjust the VR201 trimmer (for each channel) to be within this range.

BIAS ADJUSTMENT

• No bias adjustment is necessary for this ampliﬁ er circuitry; in any case the ampliﬁ er has the possibility to adjust it if necessary. To check properly the bias proceed as follows:

• Using a sinusoidal signal (1KHz or more) and the 4E load attached, wait till the heatsink temperature reaches about 60°c.

• Turn down the signal at the smallest intensity you can read on your oscilloscope trace connected at the ampliﬁ er output.

• Zoom in the crossing region using the amplitude, timebase and trigger controls of your oscilloscope. If you see a distortion, try to eliminate it adjusting the VR202 trimmer.

• Finally, set the input level at minimum and verify with the multimeter attached across an emitter resistance (p.e. R232) that the dc voltage doesn`t exceed 10mV.

ADVICES

• If you have determinate that the problem is a short on a rail, you must check the output transistors.

• If all the transistors are OK, unsolder and lift one leg of each diode and check them.

• Check the circuit board for open foil traces.

• Use the Multimeter to check the resistors, particularly the base and emitter resistors of damaged transistor.

• If the input sinewave appears to be distorted during the negative cycle, you can assume that the problem is located somewhere in the circuitry of the positive rail.

• If the positive cycle appears distorted, you can assume that the problem is in the circuitry of the negative rail.

• The dc voltages printed on the schematics are measured with the ampliﬁ er in steady state without input signal and nominal mains voltage supply, it can be useful to localize a damage.

PROCON1500p - Test procedures

PRECAUTION

• Before removing or installing any modules and connectors, disconnect the ampliﬁ er from AC MAINS and measure the DC supply voltages across each of the power supply capacitors. If your measurement on any of the caps is greater than 10Vdc, connect a 100E 100W resistor across the applicable caps to discharge them for your safety. Remember to remove the discharge resistor immediately after discharging caps. Do not power up the ampliﬁ er with the discharge resistor connected.

• Do not check the ampliﬁ er with the speakers connected use the appropriate load resistors only.

• BE CAREFUL increasing the Variac you must not exceed the nominal mains voltage plus its tolerance (see speciﬁ cations) any upper voltage can be cause of damage.

VISUAL CHECK

• Use compressed air to clear dust in the ampliﬁ er chassis.

• Before proceed to supply the ampliﬁ er check visually the internal assembly, if appears an evident damage ﬁ nd the most possible reasons that cause it.

• Check the wiring cables for possible interruptions or shorts.

• If the damage has burnt a printed circuit board don’t try to repair it, replace with a new one.

TESTING GEAR

• Audio Generator

• Dual Trace Oscilloscope

• Digital Multimeter

• 4E 900W, 8E 1500W, 100E 100W resistors

• Variac

• Digital Thermometer (not indispensable)

SETUP

• Connect the Variac between the Mains and the ampliﬁ er and set it at zero voltage.

• Turn full counter-clockwise the LEVEL potentiometers.

• Connect the audio generator to the channel inputs and set it to 1KHz 775mVrms (0dBu) sinusoidal signal.

• Connect the two scope traces to the ampliﬁ er outputs, before the relay, and set them in DC at 50V/div. 2mS/div.

SUPPLY CHECK

• Verify with the Multimeter the NTC (RT1) and R1 paralleled resistor value, it must be about 7Kohm (at 25°c).

• Disconnect the ampliﬁ er module supplies of each channel (red and yellow wires).

• Set the Variac to the nominal mains voltage, turn on the Ampliﬁ er, then check with the Multimeter the AC supply voltages:

F1-F2 = 29±2Vac. RED secondary wires = 145±8Vac.

• Re-set the Variac at zero voltage, turn off the ampliﬁ er and reconnect the supplies at each ampliﬁ er module.

• Set up the Variac slowly monitoring the oscilloscope screen, it should display no signal; if you notice a DC voltage or a protection trips check the ampliﬁ er as suggested in the ADVICES.

• As soon as the +12VF supply circuit reaches its nominal value, all cooling fans run at their minimum and the speaker output relais (J201-202) switch.

• When the Variac ac voltage reaches the nominal voltage verify the DC supplies as follow:

+VCC = +97±6Vdc

-VCC = -97±6Vdc U501 pin 8 = +12±0.5Vdc U501 pin 4 = -12±0.5Vdc U403 pin 3 = +12.5±0.5Vdc

• If one or more voltages don’t correspond, check the rectiﬁ ers, capacitors and transformers disconnecting them from cir cuit ry.

CHANNEL CHECK

• Be sure you have dis con nect ed the load re sis tor.

• When the input sig nal exceeds -20dBu (24Vpp on output) the fans turn at their max i mum speed.

• Firstly you must check the channel without load, afterwards you must repeat the check with the loads attached, the following table reports the approx. maximum level obtainable with this amp:

out level in level no load 189Vpp +1.0dBu 1CH 4E 166Vpp +0.7dBu 2CH 4E 154Vpp +0.2dBu Bridge 8E 307Vpp +0.0dBu

LEVEL METER ADJUSTMENT

• Check if the clip led lights at -2dBu on input (~130Vpp on output), if necessary adjust the trimmers W301/2 on dis play board.

OFFSET ADJUSTMENT

• Set the input level at minimum (no signal), the output dc offset voltage must be within range ±20mV, if necessary adjust the VR201 trimmer (for each channel) to be within this range.

BIAS ADJUSTMENT

• No bias adjustment is necessary for this ampliﬁ er circuitry; in any case the ampliﬁ er has the possibility to adjust it if necessary. To check properly the bias proceed as follows:

• Using a sinusoidal signal (1KHz or more) and the 4E load attached, wait till the heatsink temperature reaches about 60°c.

• Turn down the signal at the smallest intensity you can read on your oscilloscope trace connected at the ampliﬁ er output.

• Zoom in the crossing region using the amplitude, timebase and trigger controls of your oscilloscope. If you see a distortion, try to eliminate it adjusting the VR202 trimmer.

• Finally, set the input level at minimum and verify with the multimeter attached across an emitter resistance (p.e. R232) that the dc voltage doesn`t exceed 10mV.

ADVICES

• If you have determinate that the problem is a short on a rail, you must check the output transistors.

• If all the transistors are OK, unsolder and lift one leg of each diode and check them.

• Check the circuit board for open foil traces.

• Use the Multimeter to check the resistors, particularly the base and emitter resistors of damaged transistor.

• If the input sinewave appears to be distorted during the negative cycle, you can assume that the problem is located somewhere in the circuitry of the positive rail.

• If the positive cycle appears distorted, you can assume that the problem is in the circuitry of the negative rail.

• The dc voltages printed on the schematics are measured with the ampliﬁ er in steady state without input signal and nominal mains voltage supply, it can be useful to localize a damage.

PROCON1800p - Test procedures

PRECAUTION

• Before removing or installing any modules and connectors, disconnect the ampliﬁ er from AC MAINS and measure the DC supply voltages across each of the power supply capacitors. If your measurement on any of the caps is greater than 10Vdc, connect a 100E 120W resistor across the applicable caps to discharge them for your safety. Remember to remove the discharge resistor immediately after discharging caps. Do not power up the ampliﬁ er with the discharge resistor connected.

• Do not check the ampliﬁ er with the speakers connected use the appropriate load resistors only.

• BE CAREFUL increasing the Variac you must not exceed the nominal mains voltage plus its tolerance (see speciﬁ cations) any upper voltage can be cause of damage.

VISUAL CHECK

• Use compressed air to clear dust in the ampliﬁ er chassis.

• Before proceed to supply the ampliﬁ er check visually the internal assembly, if appears an evident damage ﬁ nd the most possible reasons that cause it.

• Check the wiring cables for possible interruptions or shorts.

• If the damage has burnt a printed circuit board don’t try to repair it, replace with a new one.

TESTING GEAR

• Audio Generator

• Dual Trace Oscilloscope

• Digital Multimeter

• 4E 1100W, 8E 2000W, 100E 120W resistors

• Variac

• Digital Thermometer (not indispensable)

SETUP

• Connect the Variac between the Mains and the ampliﬁ er and set it at zero voltage.

• Turn full counter-clockwise the LEVEL potentiometers.

• Connect the audio generator to the channel inputs and set it to 1KHz 775mVrms (0dBu) sinusoidal signal.

• Connect the two scope traces to the ampliﬁ er outputs, before the relay, and set them in DC at 50V/div. 2mS/div.

SUPPLY CHECK

• Verify with the Multimeter the NTC (RT1) and R1 paralleled resistor value, it must be about 7Kohm (at 25°c).

• Disconnect the ampliﬁ er module supplies of each channel (red and yellow wires).

• Set the Variac to the nominal mains voltage, turn on the Ampliﬁ er, then check with the Multimeter the AC supply voltages:

F1-F2 = 29±2Vac. RED secondary wires = 164±9Vac.

• Re-set the Variac at zero voltage, turn off the ampliﬁ er and reconnect the supplies at each ampliﬁ er module.

• Set up the Variac slowly monitoring the oscilloscope screen, it should display no signal; if you notice a DC voltage or a protection trips check the ampliﬁ er as suggested in the ADVICES.

• As soon as the +12VF supply circuit reaches its nominal value, all cooling fans run at their minimum and the speaker output relais (J201-202) switch.

• When the Variac ac voltage reaches the nominal voltage verify the DC supplies as follow:

+VCC = +110±7Vdc

-VCC = -110±7Vdc U501 pin 8 = +12±0.5Vdc U501 pin 4 = -12±0.5Vdc U403 pin 3 = +12.5±0.5Vdc

• If one or more voltages don’t correspond, check the rectiﬁ ers, capacitors and transformers disconnecting them from cir cuit ry.

CHANNEL CHECK

• Be sure you have dis con nect ed the load re sis tor.

• When the input sig nal exceeds -20dBu (24Vpp on output) the fans turn at their max i mum speed.

• Firstly you must check the channel without load, afterwards you must repeat the check with the loads attached, the following table reports the approx. maximum level obtainable with this amp:

out level in level no load 210Vpp +2.0dBu 1CH 4E 184Vpp +1.7dBu 2CH 4E 170Vpp +1.0dBu Bridge 8E 343Vpp +0.6dBu

LEVEL METER ADJUSTMENT

• Check if the clip led lights at -2dBu on input (~140Vpp on output), if necessary adjust the trimmers W301/2 on dis play board.

OFFSET ADJUSTMENT

• Set the input level at minimum (no signal), the output dc offset voltage must be within range ±20mV, if necessary adjust the VR201 trimmer (for each channel) to be within this range.

BIAS ADJUSTMENT

• No bias adjustment is necessary for this ampliﬁ er circuitry; in any case the ampliﬁ er has the possibility to adjust it if necessary. To check properly the bias proceed as follows:

• Using a sinusoidal signal (1KHz or more) and the 4E load attached, wait till the heatsink temperature reaches about 60°c.

• Turn down the signal at the smallest intensity you can read on your oscilloscope trace connected at the ampliﬁ er output.

• Zoom in the crossing region using the amplitude, timebase and trigger controls of your oscilloscope. If you see a distortion, try to eliminate it adjusting the VR202 trimmer.

• Finally, set the input level at minimum and verify with the multimeter attached across an emitter resistance (p.e. R232) that the dc voltage doesn`t exceed 10mV.

ADVICES

• If you have determinate that the problem is a short on a rail, you must check the output transistors.

• If all the transistors are OK, unsolder and lift one leg of each diode and check them.

• Check the circuit board for open foil traces.

• Use the Multimeter to check the resistors, particularly the base and emitter resistors of damaged transistor.

• If the input sinewave appears to be distorted during the negative cycle, you can assume that the problem is located somewhere in the circuitry of the positive rail.

• If the positive cycle appears distorted, you can assume that the problem is in the circuitry of the negative rail.

• The dc voltages printed on the schematics are measured with the ampliﬁ er in steady state without input signal and nominal mains voltage supply, it can be useful to localize a damage.

PROCON2200p - Test procedures

PRECAUTION

• Before removing or installing any modules and connectors, disconnect the ampliﬁ er from AC MAINS and measure the DC supply voltages across each of the power supply capacitors. If your measurement on any of the caps is greater than 10Vdc, connect a 100E 150W resistor across the applicable caps to discharge them for your safety. Remember to remove the discharge resistor immediately after discharging caps. Do not power up the ampliﬁ er with the discharge resistor connected.

• Do not check the ampliﬁ er with the speakers connected use the appropriate load resistors only.

• BE CAREFUL increasing the Variac you must not exceed the nominal mains voltage plus its tolerance (see speciﬁ cations) any upper voltage can be cause of damage.

VISUAL CHECK

• Use compressed air to clear dust in the ampliﬁ er chassis.

• Before proceed to supply the ampliﬁ er check visually the internal assembly, if appears an evident damage ﬁ nd the most possible reasons that cause it.

• Check the wiring cables for possible interruptions or shorts.

• If the damage has burnt a printed circuit board don’t try to repair it, replace with a new one.

TESTING GEAR

• Audio Generator

• Dual Trace Oscilloscope

• Digital Multimeter

• 4E 1300W, 8E 2200W, 100E 150W resistors

• Variac

• Digital Thermometer (not indispensable)

SETUP

• Connect the Variac between the Mains and the ampliﬁ er and set it at zero voltage.

• Turn full counter-clockwise the LEVEL potentiometers.

• Connect the audio generator to the channel inputs and set it to 1KHz 775mVrms (0dBu) sinusoidal signal.

• Connect the two scope traces to the ampliﬁ er outputs, before the relay, and set them in DC at 50V/div. 2mS/div.

SUPPLY CHECK

• Verify with the Multimeter the NTC (RT1) and R1 paralleled resistor value, it must be about 7Kohm (at 25°c).

• Disconnect the ampliﬁ er module supplies of each channel (red and yellow wires).

• Set the Variac to the nominal mains voltage, turn on the Ampliﬁ er, then check with the Multimeter the AC supply voltages:

F1-F2 = 29±2Vac. RED secondary wires = 173±10Vac.

• Re-set the Variac at zero voltage, turn off the ampliﬁ er and reconnect the supplies at each ampliﬁ er module.

• Set up the Variac slowly monitoring the oscilloscope screen, it should display no signal; if you notice a DC voltage or a protection trips check the ampliﬁ er as suggested in the ADVICES.

• As soon as the +12VF supply circuit reaches its nominal value, all cooling fans run at their minimum and the speaker output relais (J201-202) switch.

• When the Variac ac voltage reaches the nominal voltage verify the DC supplies as follow:

+VCC = +115±8Vdc

-VCC = -115±8Vdc U501 pin 8 = +12±0.5Vdc U501 pin 4 = -12±0.5Vdc U403 pin 3 = +12.5±0.5Vdc

• If one or more voltages don’t correspond, check the rectiﬁ ers, capacitors and transformers disconnecting them from cir cuit ry.

CHANNEL CHECK

• Be sure you have dis con nect ed the load re sis tor.

• When the input sig nal exceeds -20dBu (20Vpp on output) the fans turn at their max i mum speed.

• Firstly you must check the channel without load, afterwards you must repeat the check with the loads attached, the following table reports the approx. maximum level obtainable with this amp:

out level in level no load 225Vpp +2.0dBu 1CH 4E 200Vpp +1.7dBu 2CH 4E 185Vpp +1.0dBu Bridge 8E 373Vpp +0.6dBu

LEVEL METER ADJUSTMENT

• Check if the clip led lights at -2dBu on input (~150Vpp on output), if necessary adjust the trimmers W301/2 on dis play board.

OFFSET ADJUSTMENT

• Set the input level at minimum (no signal), the output dc offset voltage must be within range ±20mV, if necessary adjust the VR201 trimmer (for each channel) to be within this range.

BIAS ADJUSTMENT

• No bias adjustment is necessary for this ampliﬁ er circuitry; in any case the ampliﬁ er has the possibility to adjust it if necessary. To check properly the bias proceed as follows:

• Using a sinusoidal signal (1KHz or more) and the 4E load attached, wait till the heatsink temperature reaches about 60°c.

• Turn down the signal at the smallest intensity you can read on your oscilloscope trace connected at the ampliﬁ er output.

• Zoom in the crossing region using the amplitude, timebase and trigger controls of your oscilloscope. If you see a distortion, try to eliminate it adjusting the VR202 trimmer.

• Finally, set the input level at minimum and verify with the multimeter attached across an emitter resistance (p.e. R232) that the dc voltage doesn`t exceed 10mV.

ADVICES

• If you have determinate that the problem is a short on a rail, you must check the output transistors.

• If all the transistors are OK, unsolder and lift one leg of each diode and check them.

• Check the circuit board for open foil traces.

• Use the Multimeter to check the resistors, particularly the base and emitter resistors of damaged transistor.

• If the input sinewave appears to be distorted during the negative cycle, you can assume that the problem is located somewhere in the circuitry of the positive rail.

• If the positive cycle appears distorted, you can assume that the problem is in the circuitry of the negative rail.

• The dc voltages printed on the schematics are measured with the ampliﬁ er in steady state without input signal and nominal mains voltage supply, it can be useful to localize a damage.

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