Service Manuals, User Guides, Schematic Diagrams or docs for : . Rare and Ancient Equipment PRIMARE A32 hfe_primare_a32_power_service_en
<< Back | HomeMost service manuals and schematics are PDF files, so You will need Adobre Acrobat Reader to view : Acrobat Download Some of the files are DjVu format. Readers and resources available here : DjVu Resources
For the compressed files, most common are zip and rar. Please, extract files with Your favorite compression software ( WinZip, WinRAR ... ) before viewing. If a document has multiple parts, You should download all, before extracting.
Good luck. Repair on Your own risk. Make sure You know what You are doing.
Image preview - the first page of the document
>> Download hfe_primare_a32_power_service_en documenatation <<
Text preview - extract from the document
PRIMARE
A32 Power Amplifier
Service Manual
1. Technical Description.
2. Error codes.
3. Bias Adjustment.
4. Schematics.
5. Technical Specifications.
A32 Functional Description
Features
The Primare A32 power amplifier is a fully balanced design, this means that the negative
speaker terminals are active, not ground as on an unbalanced design. When performing
measurements, test equipment (such as Audio Precision) that can handle balanced
amplifiers must be used.
The input impedance is 15K and the gain is 26dB. It is possible to obtain just above 250
undistorted watts at an 8R load (both channels driven). The frequency response are flat,
the A32 will drop down only -2dB at 100Khz.
Standby
The A32 is equipped with two standby modes, where standby mode 2 is the power save
mode. In power save mode only the standby circuit will be powered by the small standby
transformer placed on the digital PCB.
Digital control and monitoring
When power is first applied and the standby button on the front panel are pressed down
the A32 are going to initiate the startup sequence. Relay K1 will be turned on where after a
small delay will follow before relay K2 goes active to disable the inrush limiters. At the
same time bias are turned on by shutting down the voltage supplied to the optocouplers on
the amplifier channels. After a 20 second startup delay for the amplifier to settle down the
speaker relays are turned ON. During the startup sequence all safety parameters such as
DC-offset and fuses will be monitored, if an error is spotted the amplifier will refuse to start
and the standby LED will flash rapidly to indicate that an error has occurred. The error
code can be read out by pressing the error check switch (SW1). Description of the error
codes can be found on the next page.
If the standby switch is pressed when the amplifier is in operate mode it will go to standby
mode 1, which means that bias and speaker relay will be switched off. The standby LED is
going to half light intensity to indicate that the amplifier is in this standby mode.
If the standby button are pressed down for more than one second the amplifier are
shutting down into standby mode 2 which means that bias, speaker relay and the two
power relays K1, K2 are switched off. Only the standby circuit is still powered consuming
just a few watt of energy.
Temperature protection
When temperature has reached 70 centigrade at the temperature sensors the speaker
relay and bias are going to be switched off, when the temperature have decreased 10
centigrade the A32 are going to be restarted. In practice this will mean that the warmest
part of the heatsink will be around 75-80 centigrade when over- temperature protection
cuts in.
General Protection
During operation mode DC-offset, fuse, temperature and AC-loss are constantly
monitored, any abnormal function from these will immediately disengage the speaker relay
and the standby LED will start to flash rapidly indicating that an error has been spotted.
The error code can be checked by pressing the error check button (SW1), if more than one
error at the same time a repeated press of the button will display the next error.
DC-offset and over temperature will automatically resume to normal operation after a delay
if the error recovers. Fuse error will not (latch), here the amplifier must be turned off and
the fuses replaced before normal operation is possible.
Trigger.
If a 3.5mm teleplug are connected to the left trigger input (the right connector is the
output) the function of the standby button are being changed to only be able to turn the
amplifier into standby mode 2 directly. The standby button cannot turn the amplifier on
while the trigger is connected (trigger mode enable). The circuit will trigger at 2.5V and are
highly immune against disturbances. The trigger are only able to control the amplifier
between operate and standby mode 1.
RS232
The RS232 port can be used for firmware upgrading as well as controlling by Crestron
compatible RS232 codes.
Fuses
Due to the large capacitance of the electrolytics bank, turn off the mainspower and wait
minimum 15minutes before replacing a blown fuse. Make sure to replace a blown fuse with
exactly the same type and value.
Error codes
LED Nr
3 2 1 Error
0 0 0 All OK
0 0 1 DC L+
0 1 0 DC L-
0 1 1 DC R+
1 0 0 DC R-
1 0 1 Fuse Rch
1 1 0 Fuse Lch
1 1 1 Overheated
Bias Adjustment
Critical for the adjustment are that the mainsvoltage is 230V or 120V exactly.
The temperature in the facility must be constant during the adjustment procedure.
Use the Bias test points and potentiometers (R1, R2) to adjust bias on each channel.
The lower potentiometer is accessible thru a hole in the bottom of the amplifier.
Bias test points
Compare the voltage
drop over all of the
emitter resistors.
These steps describe the Bias adjustment procedure, which is the same for both L& R
channels.
1. Switch the amplifier on or if it has been on burn-in (test), disconnect input signal and
loads. The A32 amplifier must be in operate mode, bias will be switched off in standby.
2. Let the amplifier run for 1h, without input signal.
3. Adjust the bias to 17mV measured on JP3, JP4 or JP2, JP1.
4. Check the maximum difference (voltage drop) over emitter resistors (R241, R243,
R245, R247, R239, R237, R235, R233, R240, R238, R236, R234, R242, R244, R246,
R248). The difference between them should not exceed 7mV. Higher difference might
be due to a faulty transistor or Emitter resistor, also check and that the screw are
tightened.
5. Wait 1h.
6. Measure the bias and if needed readjust to 17mV measured on JP3, JP4 or JP2, JP1.
7. Wait 1h.
8. Measure the bias and if needed readjust to 17mV measured on JP3, JP4 or JP2, JP1.
9. Wait 1h.
10. Measure the bias and if needed readjust to 17mV measured on JP3, JP4 or JP2, JP1.
Repeat step 5-9 until the bias are stabile.
1 2 3 4 5 6 7 8
U4
T1
P6 LD1085V33
S1 +3.3VD
1 15 3 2 C33
D12 Vin Vout
SW3
ADJ
T500mA 4
PLUG 3 +3.3V
PCB 2
C4
4 13 100U/6.3V PHONEJACK STEREO SW
5 2 BRIDGE1 C31 R32 J6
5 11 C32 100n R26
1
2200U/25V
6 1 100n 4K7
P7 Q5 4K7
240V 8 9 BC846 D4 D6 R1
D LL4148 LL4148 2K2 D
PLUG SW120-240
TRANSF53X44 J5
D8 +3.3VD R9
R42
2K2
470K +3.3V
LL4148 C24 Standby mode R44
R19 10R C23
1
C1 4K7 C27 R21 D5 D7 R24
47nF/275V X2 330N 100N C22 510R LL4148 LL4148 100N 10R PHONEJACK STEREO SW
S3 S2 100N
K1 Q2 BCV46 SW-SPDT NC
RELAY DPDT3
3
2
R45
1
2
3
4
SW BAL/UNBAL
P1 10K
+3.3V
NO1
C1
COIL COIL
NC1
R39 R37 R38 D2 R11
PLUG NTC 7R NTC 7R NTC 7R BDY17D 470R Q6
BC846 R3 R2
NC2
P9 P3 N02 NC C8 C9
+3.3V NC
C2
RS232
C11 U2
R22
100N
100N
PLUG PLUG 100N 16 1
120V
240V
F1
8
7
6
5
+3.3VD VCC C1+
3
2
1
4K7 C26 15 2
P10 P4 100U/25V GND V+
14 3
T1OUT C1-
K2 Q4 BCV46 13 4 NMF40 P2
R1IN C2+
RELAY DPDT3 12 5
C R1OUT C2- 4 C
PLUG PLUG 11 6
R23 T1IN V- 3
1
2
3
4
10 7
9
8
7
6
5
4
3
2
1
10
P8 T2IN T2OUT 2
10K 9 8
R2OUT R2IN 1
NO1
C1
COIL COIL
NC1
D3 J3 J4 MAX3232ECAE HEADER 4
PLUG C2 BDY17D Q7 CON10 CON10
R12 470R BC846
NC2
N02
47nF/275V X2 C12 C10
C2
10
To mains Transformer 100N
9
8
7
6
5
4
3
2
1
100N F2
3
2
1
NMF40
+3.3VD R4
8
7
6
5
4K7
+3.3VD
R43
C28 10R
2
4
6
8
C19 C20 C25 SW2
47u/16V 100N 100N 10N
PIN4 ON P5 D1
+3.3VD PCB3 PIN3 ON P5
KB2855
PCB4
R46 R47 R25
1
3
5
7
10K 10K 2K2
Q1 Q3 +3.3VD PIN1 ON P5
PIN2 ON P5
R10 +3.3VD
B 2K2 P5 HEADER 4 B
LL4148 LL4148 LL4148 LL4148 LL4148 LL4148
4
3
2
1
BCV46 BCV46 D13
10K
10K
R15 10K
R16 10K
R14 10K
R13 10K
J2
Bias R LL4148
1
SPK Relay R
R27
D14
R28
2
XLR/RCA R +3.3VD
3
+15V R D15
4 D16 D17 LL4148 R41 110R
GND R D18 D19 D20 U3 U5
5 R20
Temp1 R 1 28 14 15
6 P2.0/ICB/DAC0/ADC03 P2.7/ICA SER O0 R40 412R
Temp2 R 2 27 1 1K
7 P2.1/OCD/AD02 P2.6/OCA O1
Fuse R 3 26 11 2
8 P0.0/CMP2/KBI0/AD01P0.1/CIN2B/KBI1/AD10 SRCLK O2
DC-Check+ R 4 25 10 3 D11
9 ◦ Jabse Service Manual Search 2024 ◦ Jabse Pravopis ◦ onTap.bg ◦ Other service manual resources online : Fixya ◦ eServiceinfo