PRIMARE

A32 Power Amplifier Service Manual

1. Technical Description.

2. Error codes.

3. Bias Adjustment.

4. Schematics.

5. Technical Specifications.

Confidential ! This document is not allowed to show for third part without written permission from Primare Systems AB. This document is subject to change without notice. Author: Bjorn Holmqvist Primare Systems AB bjorn@primare.net

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

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Date: 14-Nov-2005 Sheet of File: C:\WORK\..\P2005-3D.SCH Drawn By:

C4

2200

U/2

5V

S1

T500mAD12

BRIDGE1

123456789

10

J1

CON10

Bias LSPK Relay LXLR/RCA L+15V L

Temp1 LTemp2 L

GND L

Fuse LDC-Check+ LDC-Check- L

123456789

10

J2

CON10

Bias RSPK Relay RXLR/RCA R+15V R

Temp1 RTemp2 R

GND R

Fuse RDC-Check+ RDC-Check- R

R50R

R60R

R7536R

R8560R

R9

2K2

R21510R

R2410R

R26

4K7

R332R2

R342R2

SW B

AL/

UN

BA

L

Q1

BCV46

R10

2K2

R25

2K2

C1+ 1

V+ 2

C1- 3

C2+ 4

C2- 5

V- 6

T2OUT 7

R2IN 8

R1IN13

R1OUT12

R2OUT9

VCC16

GND15

T1OUT14

T2IN10 T1IN11

U2

MAX3232ECAE

1234

P2

HEADER 4

123F1

NMF40

123 F2NMF40

C8

100N

C9

100N

C10100N

C11100N

C12100N

+3.3V

RS2

32

NO

11

N02

8

C1

2C

27

NC

13

NC

26

CO

IL4

CO

IL5

K1RELAY DPDT3

786

3

2

5

4

1

D1KB2855

R37NTC 7R

R38NTC 7R

R39NTC 7R

NO

11

N02

8

C1

2C

27

NC

13

NC

26

CO

IL4

CO

IL5

K2RELAY DPDT3

240V

120V

Q2 BCV46

R11

470R

Q4 BCV46

R12 470R

D2BDY17D

D3BDY17D

P2.0/ICB/DAC0/ADC031

P2.1/OCD/AD022

P0.0/CMP2/KBI0/AD013

P1.7/OCC/AD004

P1.6/OCB5

P1.5/RST6

VSS7

P3.1/XTAL18

P1.0/TXD 18

P0.5/CMPREF/KBI5 22

VDD 21

P0.1/CIN2B/KBI1/AD10 26

P0.3/CIN1B/KBI3/AD12 24

P0.6/CMP1/KBI6 20

P0.2/CIN2A/KBI2/AD11 25

P1.1/RXD 17

P3.0/XTAL2/CLKOUT9

P1.4/INT110

P1.3/INT0/SDA11

P1.2/T0/SCL12

P2.5/SPICLK 16

P0.4/CIN1A/KBI4/AD13 23

P2.2/MOSI13

P2.3/MISO14

P2.7/ICA 28

P0.7/T1/KBI7 19

P2.4/SS 15

P2.6/OCA 27

U3

P89LPC935

R13

10K

R14

10K

R15

10K

R16

10K

R27

10K

R28

10K

C13

100U/6.3V

C14

100U/6.3V

C15

100U/6.3V

C16

100U/6.3V

+3.3VD

X2

4MHZ

C1710p

C1822p

SER14

SRCLK11

SRCLR10

RCLK12

E13

O0 15

O1 1

O2 2

O3 3

O4 4

O5 5

O6 6

O7 7

Q7 9

VCC16

GND8

U5

74LVC595

+3.3VD

R29

3K3

R30

3K3

R31

3K3

D9LED

D10LED

D11LED

R40 412R

R41 110R

+3.3VD

C22100N

D4LL4148

D5LL4148

R32

4K7Q5BC846

4

2

3

1SW1

SW-B3

R18

10K

+3.3VD

Check error

+3.3V

D6LL4148

D7LL4148

C23

100N

12345678910

J3CON10

12345678910

J4CON10

S2NC

123

S3SW-SPDT

+3.3VStandby mode

R19

4K7

+3.3V

+3.3VD

+3.3VD

R42

470KC24

330N

D8

LL4148

+3.3VD

1234

P5 HEADER 4

SW2

R20

1K

PIN4 ON P5

PIN3 ON P5

PIN2 ON P5PIN1 ON P5

PCB 2

PCB3 PCB4

P6

PLUG

P7

PLUG

C147nF/275V X2

C2

47nF/275V X2

P1

PLUG

P3

PLUG

P4

PLUG

P8

PLUG

P9

PLUG

P10

PLUG

1

8

15

13

9

11

4

5

T1

TRANSF53X44

16

2

3

5

4SW3

SW120-240

240V

To mains Transformer

C19100N

C20100N

C2510N

R4310R

C26100U/25V

J5

PHONEJACK STEREO SW

J6PHONEJACK STEREO SW

C27100N

R4410R

C28

47u/16V

R12K2

R2NC

R3NC

Q6BC846

Q7BC846

R4

4K7

R22

4K7+3.3VD

R23

10K

R45

10K

R46

10KQ3

BCV46

R47

10K

C29100U/6.3V

C30100U/6.3V

Vin3

AD

J1

Vout 2

U4LD1085V33

C31100nC32

100n

C33

100U/6.3V

+3.3VD

+3.3VD

D13

LL4148D14

LL4148D15

LL4148

D16

LL4148

D17

LL4148

D18

LL4148

D19

LL4148

D20

LL4148

D21LL4148 D22

LL41

48

D23

LL41

48

D24

LL4148

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Date: 7-Dec-2005 Sheet of File: C:\WORK\..\P2005-8C.SCH Drawn By:

Q12SC2240

Q92SA970

Q13BD677A

Q152SC5171

Q662SA1930

R11K

Q69

2SA1943

Q77

2SC5200

R333K

R710K

R11110R

R13

470R

D1

1N41

48

D2

1N41

48

C10.1U

R31

5K6

R32

5K6

R355K6

R403K3

Q10

2SA970

R4215K

R4312K

C1422PF

Q22SC2240

Q32SC2240

Q42SC2240

R46133R

R481K5

R14

470R

R207

1K

R209

22K

C84

39P

D3

1N4148

D41N4148

C2

0.1U

R15

470R

R213220R

R217100R

R16

470R

R221

4K7

R222

4K7

R223

4K7

R229470K

A1

K2

C 4

E 3

Q85

OPTOISO1

1

2

3

Q87BS107

R214

330R

R231680R

R2242K2

R491K1

Q172SC5171

R1756R

R1856R

C40.1U

C86

220U/16V

R19220R

R20220R

R2330.22R

R2340.22R

R249

22R

R250

22R

R251

22R

R252

22R Q70

2SA1943

Q78

2SC5200

R2350.22R

R2360.22R

R253

22R

R254

22R

R255

22R

R25622R

S1

6.3A

S2

6.3A

C88100N

C89100N

R210

22K

R2831K

C50.1U

C901U

R296

1M

+15V

-15V

C60.1U

C940.1U

C96100U/63V

C97100U/63V

R2984R7

C70.1U

R21

470RBIAS

Q89A2SK389

Q89B2SK389

+50V

-50V

U1

TL071

R284

1K1C110NC

12

JP3

C98

100U

/63V

C99100U/63V

Q71

2SA1943

Q79

2SC5200

R2370.22R

R2380.22R

R257

22R

R258

22R

R259

22R

R260

22R

Q72

2SA1943

Q80

2SC5200

R2390.22R

R2400.22R

R261

22R

R262

22R

R263

22R

R26422R

R285

1K

R30015K

R218

100R

R286

1K

R219

100R

R287

1K

R301

22K

R30222K

C112330P

C113330P

C114330P

3

21

84

U9AOPA2134

5

67

U9BOPA2134

3

21

84

U10AOPA2134

5

67

U10B

OPA2134

S4A

SW SPDT

S4B

SW SPDT

45

S4C

R288

1K

R289

1K

R290

1K

R291

1K

R30347K

R30447K

R265

22R

R266

22R

Q52SC2240

Q112SA970

Q14BD677A

Q182SC5171

Q672SA1930

1

W

2R21K

Q73

2SA1943

Q81

2SC5200

R433K

R810K

R12110R

R22

470R

D17

1N41

48

D18

1N41

48

C80.1U

R37

5K6

R38

5K6

R395K6

R413K3

Q12

2SA970

R4415K

R4512K

C15 22P

Q62SC2240

Q72SC2240

Q82SC2240

R47133R

R501K5

R23

470R

R208

1K

R211

22K

C85

39P

D19

1N4148

D201N4148

C9

0.1U

R24

470R

R215220R

R220100R

R25

470R

R225

4K7

R226

4K7

R227

4K7

R230470K

A1

K2

C 4

E 3

Q86

OPTOISO1

1

2

3

Q88BS107

R216

330R

R232680R

R2282K2

R511K1

Q642SC5171

R2656R

R2756R

C100.1U

C87

220U/16V

R28220R

R29220R

R2410.22R

R2420.22R

R267

22R

R268

22R

R269

22R

R270

22R Q74

2SA1943

Q82

2SC5200

R2430.22R

R2440.22R

R271

22R

R272

22R

R273

22R

R27422R

C91100N

C92100N

R212

22K

R2921K

C110.1U

C931U

R297

1M

+15V

-15V

C120.1U

C950.1U

C100100U/63V

C101100U/63V

R2994R7

C130.1U

R30

470RBIAS

Q90A2SK389

Q90B2SK389

+50V

-50V

3

26

74

U8

TL071

R293

1K1C111NC

C102

100U

/63V

C103100U/63V

Q75

2SA1943

Q83

2SC5200

R2450.22R

R2460.22R

R275

22R

R276

22R

R277

22R

R278

22R

Q76

2SA1943

Q84

2SC5200

R2470.22R

R2480.22R

R279

22R

R280

22R

R281

22R

R28222R

C3

2200

U/5

0V

C17

2200

U/5

0V

C18

2200

U/5

0VC

1922

00U

/50V

C11

910

0NC

120

100N

R306

10R

R307

10R

C127

220U/35V

C128

220U/35V

+15V

-15V

Vin1

GN

D2

OUT 3

U117815

Vin2

GN

D1

OUT 3

U127915

Q65 2SC4793

Q682SA1837

R522K2

R2062K2

C129470U/35V

C130470U/35V

D2324V

D2424V

C13110U/50V

C13210U/50V

+50V-POWER

-50V-POWER

+50V-POWER

-50V-POWER

+50V-POWER +50V

-50V-50V-POWER

C121

100N

+15V

+15V

-15V

-15V

-15V

+15V

C122100N

C123100N

C124100N

C125100N

C126100N

C133220U/50V

C134220U/50V

12

JP4

C106

100U/63V

C107

100U/63V

C108

100U/63V

C109

100U/63V

123456789

10

J6

CON10

BIASSPK-RELAY

FUSE-ERROR

R520K

R620K

FUSE-ERROR

DC-CHECK +

DC-CHECK -

DC-CHECK -DC-CHECK +

Q91BC846

D21

1N4007

R309560R/3W

12

3

4 5

S8

RELAY-SPDT

R310100K

R2944K7

SPK-RELAYQ92BC846

D221N4148

R311100K

R295

4K7XLR/RCA

+15VR312

100R

XLR/RCA

R9

10K

R10

10K

C16

NC

C83

NC

+15V

C20

2200

U/5

0V

C21

2200

U/5

0V

C22

2200

U/5

0V

C23

2200

U/5

0V

C24

2200

U/5

0V

C25

2200

U/5

0V

C261U/250V

C271U/250V

C28

100N

C29

100N

C30100n

C31100n

C32100n

C33100n

RV1KTY81

OUT(+)

OUT(-)

C34100N

C35100N

C3610N

R3310R

R340R

R360R

R53

100R

R54

100R

R55

100R

GNDXLR+

XLR-

RCA INRCA-GND

C37

100U/50V

R56

1KR57

1K

R581K

R591K

12

JP1

12

JP2

R6010R

R6110R

R6210R

R6310R

1 2 3 4

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Date: 7-Dec-2005 Sheet of File: C:\WORK\..\P2005-4B.SCH Drawn By:

D1

BRIDGE1

C115000/63V

C215000/63V

C315000/63V

C415000/63V

C515000/63V

C615000/63V

D2

BRIDGE1

D3

BRIDGE1

C715000/63V

C815000/63V

C915000/63V

C1015000/63V

C1115000/63V

C1215000/63V

D4

BRIDGE1

P1

PLUG

P2

PLUG

P3

PLUG

P4

PLUGP5

PLUG

P6

PLUG

P7

PLUG

P8

PLUG

P9

PLUG

P10

PLUG

P11

PLUG

P12

PLUG

P13

PLUG

P14

PLUG

R1MRS25

R2MRS25

R322k

R422k

Performance Data 2000VA Torodial Transformer. A total of 180 000 uF electrolytes in the powersupply. Dual set of Speakerterminals for each channel. Balanced (RCA) and Unbalanced (XLR) inputs. Input impedance 15K, RCA and XLR Output Power (both channel driven): 2x250W 8Ohms load 20Hz-20Khz 2x400W 4Ohms load 20Hz-20Khz THD+N below 0.05% in both cases. Frequency response: 20Hz-100Khz –0.5dB Noise, below –100dBV THD+N: 1K 250W 8R load below 0.01%. Gain: 26dB unbalanced, 20dB balanced. Trigger input range: 4-15V.