Classe Audio CP-47.5 User manual

CP-47.5
Classé
PREAMPLIFIER
SERVICE MANUAL
v 1.0

Index
Mechanical Assembly 3
PC Boards 17
Testing Procedures 30
Diagrams 33

CP-47.5
MECHANICAL
ASSEMBLY

1 MS-2347 PHILIPS
2 L1A2XR01
3 L1A3XR02
CP-47.5
FACE PLATE ASSEMBLY
Classé - 1
MODEL CP-47.5MODEL CP-47.5
STANDBYSTANDBY SELECTOR
SELECTOR
<<TAPETAPE MUTEMUTE
3
1
2

FACE PLATE ASSEMBLY
1
2
3
4
5 L214XR01-S
6
Classé - 2
CP-47.5
1
2
3
6
5
4
TOP VIEW
SIDE VIEW 1
SIDE VIEW 2

CHASSIS REAR VIEW
1
2
3
4
5
6
7
8
8
7
5
6
1
2
Classé - 3
3
4
CP-47.5

CHASSIS REAR VIEW
1
2
3
Classé - 3
CP-47.5
1
2
3

CHASSIS
1 PLA CAPFR1
2 HDW #8 FLAT WASHER
3 BZO 8-32x3/4” BHCS
4 L1A1XR03
Classé - 6
1
2
3
CP-47.5
4
TOP VIEW

Classé - 8
PARTIAL ASSY
1 AVR BO51XR02
2 AVR BO50XR03
3 AVR BO1CXR00
4 TRANSFORMER
CP-47.5
TOP VIEW

Classé - 8
PHONO BOARD INSTALLATION
1
2
CP-47.5
SIDE VIEW
1
2

SHIPPING AREA - FINAL ASSY
1 L1A5XR00
2
Classé - 9
CP-47.5
MODEL CP-47.5
MODEL CP-47.5
STANDBY
STANDBYSELECTOR
SELECTOR
<<TAPE
TAPE MUTEMUTE
2
1

CP-47.5
PC BOARDS

B1A1XR04 MAINBOARD
Classé - 10
CP-47.5

B1A2XR02 FRONT PCB
Classé - 11
CP-47.5

B1A3XR01 DISPLAY
Classé - 11
CP-47.5

B0F9XR02 PHONO
Classé - 11
CP-47.5

CP-47.5
TESTING
PROCEDURES

Classé - 14
START - UP
1-check all wires and components
2-Check screws and bolts
3-Connect the jumpers for 120 Volts
4-Turn the bias all the way to 0 volts
5-Connect the unit in bypass mode
6-Connect the unit with variable transformer
7-Connect speaker cables, regular and balanced inputs
8-Apply 10V AC from variable transformer and check the rail and driver voltages
9-If the unit is OK increase the voltage up to 120V
10-Turn off the unit and remove by pass
11-Turn on the unit and check the rails driver and offset
12-Check the sequence of relay clicking
13-Adjust the bias and offset
14-Check the protection circuit both channels
15-Check the signal with 8 and 4 load in
16-Regular, regular mono, balanced stereo and balanced mono
17-Check noise with small speaker and RCA shorted plug
18-Put in burning bench
CP-47.5

CP-47.5
FINAL TEST
Classé - 15
1. Before final test unit was 4 days on burn-in-bench with music.
2. Take the unit from burn-in-bench to Q.C and play it immediately. Keep the line 120V A.C.
3. Check physically and check the components.
-check all capacitor and devices direction. Capacitor stand up right way i.e. check co-
solder.
-check any missing parts.
-check all fuse sockets.
-check main board tight up with screw and washer.
-check any screw missing.
-check balance lock working smoothly.
-check all output transistors position with pad.
-check main transistors position with pad.
-check main transformer tight very well.
4. Adjust bias 26mV for every output devices for both channels. Wait 7 to 8 minutes after
each adjustment. Also adjust offset to 0mV.
5. Measure rail and pre-driver voltage.
6. Measure A.C voltage for bridge.
7. Measure supply voltage for relays. +15V and 15V for both channels. +12V and 12V.
8. Measure reference voltage 8.1V on both channels.
9. Measure reference voltage for protection 78V.
10. After setting the bias, connect load and input signal. Check output signal. Check phase
with input signal.
11. Measure frequency response, slew rate, gain, signal to noise ratio.
12. Check the output signal from 20Hz to 20KH with load in following combination. Also
measure the output power.
Regegur-stereo
Balance-stereo
Regegur-mono
Balance-mono
13. Check phone-jack.
14. Check protection on both channels.
15. Check noise with speaker.
16. Put the jumpers and varistor for required A.C voltage.
17. Plug unit again and check rail and pre-driver voltage.

CP-47.5
DIAGRAMS