DiVA Service Manual Issue 1.
Arcam P-1000 Amplifier Board functions and operation The power amplifiers in the P-1000 are of class H design and use a three rail power supply for high operating efficiency. These amplifier boards are field replaceable and the unit can be safely operated with one or more boards out of the unit. The operating descriptions below are divided into three groups. The input and signal control section. The amplifier section and the power switching section.
Arcam P-1000 Amplifier Board functions and operation In the amplifier portion of the board, Q2 acts as a level shifter and drives the class A transistor Q13. The voltage source for the class A stage is from Q14 and is regulated by Z1. This constant voltage causes Q13 to act as a constant current source and stabilizes the output transistor bias regardless of changes in the AC mains. The class A drive voltage is also removed from Q13 anytime the local or global mute circuits are activated.
Arcam P-1000 Amplifier Board functions and operation With the amplifier operating at low output levels (<20 W) only the +/-20V low voltage rails are used. As the output requirements increase, the COMM signal from U2-A also increases and the peak value of this signal is compared to the low rail reference voltage at the comparators U4-A and U5-B. When the peak value of the COMM signal exceeds the reference the comparators will toggle on and the middle rail voltage will be supplied to the amplifier.
FIGURE 1 POSITIVE RAIL SWITCHING WAVEFORM FIGURE 2 FIGURE 3 NEGATIVE GOING WAVEFORM BIAS CONTROL AT MAX CCW POSITION
FIG 4 BIAS PROPERLY ADJUSTED (COLD)
P-1000 Display Board functions and operation. The P-1000 display functions are divided into two separate blocks, power on/off and channel status indications. The power on/off LED indicators are driven by the Standby Power supply on the main board and are active any time the P-1000 is connected to the AC mains supply and the rear panel power switch is on. The Channel Status LEDs receive power from both the Main power supply and from each individual amplifier channel.
Arcam P-1000 Main Board functions and operation In addition to the high current supply voltages for the seven amplifier channels, the Main board also contains the circuitry for power on/off control, DC fault protection, the standby housekeeping power and other control circuits as well as the bussing interconnections to all channels. Since the P-1000 is a multi rail class H amplifier, the Main board has three high power plus/minus voltage supplies for the amplifier output stages.
Arcam P-1000 Main Board functions and operation To perform these functions an AC mains sine wave from the standby transformer secondary is applied to the input of U2-D. This LV_AC_IN signal is then half wave rectified and the output of gate U2-D is a square wave clock signal to the CLK input of U-1B. By using a clock signal derived from the AC mains, zero crossing turn on/off is assured regardless of which method is used.
ARCAM P-1000 AMPLIFIER BOARD Reference No CAPACITOR C1 C45 C2 C3 C4 C22 C23 C39 C42 C5 C6 C7 C25 C36 C37 C43 C46 C47 C48 C8 C9 C10 C32 C33 C34 C35 C40 C41 C11 C15 C12 C13 C49 C16 C26 C27 C28 C29 C17 C18 C19 C20 C21 C24 C30 C31 C38 C44 C50 C51 DIODE D1 D2 D3 D4 D5 D6 D9 D10 D11 D12 D7 D23 D24 D25 D8 D13 D16 D19 D20 D21 D22 TRANSISTOR Q1 Q2 Q4 Q5 Q15 Q16 Q22 Q23 Q3 Q14 Q6 Q20 Q24 Q25 Q7 Q8 Q9 Q13 Q10 Q11 Q12 Q17 Q19 Q18 Q21 RESISTOR C14 R1 Part No Description 205-813-4 210-311-4 206-529-4 203-038-4 205-509
Reference No R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R18 R19 R20 R21 R23 R24 R25 R26 R27 R28 R29 R30 R31 R32 R33 R34 R35 R36 R37 R38 R39 R40 R41 R42 R43 R44 R45 R46 Part No 109-289-4 103-072-4 103-094-4 103-107-4 109-318-4 103-113-4 103-103-4 325-004-0 103-064-4 109-348-4 103-073-4 103-107-4 103-072-4 103-103-4 103-100-4 103-083-4 103-083-4 103-103-4 103-072-4 109-219-4 103-136-4 109-235-4 103-096-4 103-073-4 103-101-4 103-028-4 116-019-0 116-019-0 109-354-4 103-060-4 103-080-4 103-039-4 105-088-
Reference No R56 R57 R58 R59 R60 R61 R62 R63 R64 R65 R66 R67 R68 R69 R70 R71 R72 R73 R74 R75 R76 R77 R78 R79 R80 R81 R82 R83 R84 R85 R86 R87 R88 R89 R90 R91 Part No 111-004-0 103-072-4 103-072-4 103-072-4 103-096-4 103-074-4 116-019-0 103-086-4 103-072-4 103-089-4 103-072-4 103-089-4 103-072-4 103-072-4 116-010-0 103-104-4 103-052-4 103-103-4 109-220-4 103-072-4 103-098-4 103-103-4 109-220-4 103-072-4 109-289-4 103-096-4 103-103-4 103-055-4 109-228-4 109-289-4 109-318-4 103-080-4 116-018-0 103-104-4 103-10
Reference No IC U1 U2 U3 U6 U4 U5 ZENER Z1 Z2 Z3 Z4 L1 CONNECTOR J1 J2 J3 J5 CON1 MISC S1 TP1 TP2 TP3 TP4 RP1 R22 JACK PLATE Part No Description 322-010-0 322-007-0 322-029-0 IC TLO82 DUAL OPAMP IC 4560 DUAL OPAMP DIP IC LM393 DUAL COMP 303-025-0 303-004-0 303-010-0 353-007-0 DIODE ZEN 4758 54V .4" DIODE ZEN 4738 8.2V .4" DIODE ZEN 4754 39V .4" INDUCTOR 6UH AXIAL 454-008-0 446-020-0 421-010-0 445-016-0 XLR FEMALE R/A PCB MT TYPE A RCA JACK DUAL VERTICAL FASTON 250 CONN 13 PIN/ST/ .
ARCAM P-1000 DISPLAY BOARD Reference No DIODE D1 D9 D10 D11 D2 D3 D4 D5 D6 D7 D8 TRANSISTOR Q1 Q2 RESISTOR R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R18 R19 MISC J1 RB1-RB2 SW1 BRACKET RA SPACER BUTTON JACK STANDOFF REVISION A Part No Description 307-010-0 302-001-4 307-010-0 DIODE LED YEL/GRN DIODE 1N4148 SIGNAL .
ARCAM P-1000 MAIN BOARD Reference No CAPACITOR C1 C2 C3 C9 C51 C4 C10 C30 C5 C55 C6 C7 C8 C11 C12 C33 C34 C35 C36 C37 C38 C39 C40 C41 C42 C43 C44 C15 C16 C17 C18 C19 C20 C21 C22 C23 C24 C25 C26 C27 C28 C29 C31 C32 C50 C45 C46 C47 C48 C49 C52 C53 C54 C63 C56 R4 - CAP USED IN THIS POSITION REVISION A Part No Description 202-101-4 202-124-4 205-509-4 205-315-4 205-517-1 210-307-4 205-513-4 CAP MYLAR .001uF 100V 5% CAP MYLAR .
Reference No R3 R4 SEE CAPACITORS R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R18 R19 R20 R21 R22 R23 R24 R25 R26 R27 R28 R29 R30 R31 R32 R33 R34 R35 R36 R37 R38 R39 R40 R41 Part No 103-123-4 Description RES CF 1/4W 5% 130K .
Reference No R49 R50 R51 R52 R53 R54 R55 R56 R57 R58 R59 R60 R61 R62 R63 R64 R65 R66 R67 R68 R69 R70 R71 R72 R73 R74 R75 R100 R101 Part No 103-111-4 103-092-4 103-116-4 103-111-4 103-092-4 103-072-4 103-096-4 103-076-4 103-092-4 103-123-4 103-123-4 103-123-4 103-123-4 103-082-4 103-048-4 114-007-0 116-006-0 115-003-6 105-100-4 105-100-4 114-007-0 114-008-0 117-002-6 117-002-6 114-007-0 114-007-0 103-089-4 103-116-4 103-123-4 Description RES CF 1/4W 5% 43K .4" RES CF 1/4W 5% 6.8K .4" RES CF 1/4W 5% 68K .
ARCAM P-1000 Item 1 15 20 25 25 30 35 40 45 50 55 60 65 70 75 80 90 95 105 110 125 130 135 140 145 150 155 165 180 185 195 200 215 220 220 230 235 240 255 265 270 305 315 330 335 Part Description REVISION A Part No HEX NUT 10MM LOCATING WASHER RUBBER MTG GASKET TRANSFORMER 800VA 115V TRANSFORMER 800VA 230V NUT 8-32 NYLOCK MTG PLATE, TRANSFORMER BOLT 10 x 115 MM FOOT SCREW SM #6 x 1/4 SCREW 8-32 x 1/2" PH WELL NUT 8-32 WASHER #8 FLAT SCREW 8-32 x 3/4 PH SCREW 6-32 x 1/4 PH FLEX TUBING 5/8" x 7.
Item Part Description Part No Where Used WIRE 18GA TEW BLU 3.5" WIRE 18GA TEW BLK 4" WIRE 18GA TEW BLK 5.5" WIRE 18GA TEW BLK 13.25" FASTON FEM 18GA INSULATED FASTON FEM 14GA INSULATED TYWRAP TYWRAP FRONT PANEL BLK FRONT PANEL SILVER DAMPING PLATE TOP COVER, BLACK TOP COVER, SILVER WIRE ASSY 18GA TEW 11.25" WIRE ASSY 18GA TEW 12.25" WIRE ASSY 18GA TEW 12.5" WIRE ASSY 18GA TEW RED 4.
