Arcam-Alpha8-int-sm维修电路原理图.pdf

H /P P SE MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL 1 Arcam Alpha One/ 7R/ 8R/ 8P Amplifier Service Manual Issue 1 Serial Number 001 - (Paul Newton/ Haider Bahrani Sept 98) Circuit Description The Alpha One / 7R/8R and 8P share a common pcb. The circuits are very similar and the main differences are the remote volume facility and extra power output on the 7R and 8R and a switch to bypass the phono stage to enable its use as an extra line level input and the AV processor switch on the Alpha 8R integrated amplifier. The 8P power amplifier utilises the same power amplifier circuit as the Alpha 8R integrated amplifier. Power Supplies The ac output of the toroidal mains transformer is rectified and smoothed by D201-204 and C204, 205. This is then regulated to +/-15V by Z201, 202 to power the phono and tone control stages and the d.c. servo. The Alpha 7R and 8R transformers have an extra tapping which is used for the remote volume circuit. The ac in is regulated to 5V by zener D902 and associated components and this is then used to power the microcontroller Z901 and remote receiver. Phono Stage (Not applicable to Alpha One) The phono stage consists of a dual opamp Z305, one opamp per channel. The RIAA equalization is achieved by the feedback components R703, 704, 702 and C704, 705, 702 on left channel (R603 etc. as above for Right channel). R703 determines the gain and C703 the low frequency roll off. On the Alpha 8R this stage can be bypassed by use of switch SW302 to enable use as an extra line input. Tone Controls The tone control stage is based around Z304 a dual op amp. The range of the controls is set by R507, 508 for the bass pot RV302 and R509, 510 for the treble pot RV303. The tone controls and balance pot can be bypassed by use of the direct switch, SW304. Power Amplifier The input to the power amplifier from previous stages is fed to the differential input of Q112 and Q113. Q110 and Q111 form a constant current source for the differential input stage. The output devices are n channel mosfets SMF045. Zener diodes D103,104 limit the voltage swing within safe limits for the output devices & fusible resistors R105, 106 provide overcurrent damage to the devices. A proportion of the output current appears across the protection network R41,42. If this becomes too high Q17 is turned on and mutes the output. High D.C. levels at the output will also mute the output. There are no output fuses on the Alpha One, 7R and 8R/8P amplifiers. The muting is done by the mute ic Z303 and its associated compontents. The mute operates on switch on/off and if an over current or over voltage condition occurs. The power led glows amber when the mute circuit is operative and glows green in normal use. Removing the Alpha One/ 7R/ 8R/ 8P Transformer The toroidal transformer is extremely well secured to the main pcb with a double sided adhesive gasket. To remove the transformer you must break this adhesive bond by cutting through the gasket. This will be easier if the transformer is warm. Use a cheese wire under the transformer, pulling backwards and forwards under tension to gradually cut through. Once most of the adhesive is cut, you should be able to pull the transformer away from the pcb. A less satisfactory substitute for cheese wire is to use some 22 gauge tinned copper wire, stretched first to remove kinks, and two temporary handles. Alpha One/7R/ 8R/ 8P Quiescent Current (IQ) Settings When replacing the output transistors of the above amplifiers it is important to reset the quiescent current (IQ) to the correct value to prevent the amplifier blowing again. The IQ should be checked and set by following the procedure below: From cold and with no load or signal connected Turn both IQ presets (RV1 and RV101) down to minimum (fully anticlockwise) and set the voltage drop across resistor R1 (R101 for right hand channel) to between 3.0 and 3.5mV for the Alpha One and 7R RadioFans.CN 收音机爱 好者资料库 H /P P SE MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL 2 amps or between 2.3 and 2.8mV for the Alpha 8R/8P amps. Leave the unit for 1 minute and reset to these values if required. Leave the unit for a further 5 minutes and reset if required. The IQ is now set and the unit can be connected to speakers and fully checked out. Disassembly For Servicing 1.Remove the top cover and front panel. 2.Remove 2 screws securing the sub front to the chassis sides and 3 screws holding the subfront to the chassis base. 3.Remove 1 screw holding the pcb to the chassis. This can be found near to the mains inlet socket. 4.Remove 5 screws from the rear panel, one at each end and 3 along the bottom edge. 5.Remove the transformer bolt. 6.Release the PCB pillar located near to the serial number on the pcb. The pcb, with the rear panel, transformer and subfront attached, can now be pulled backwards out of the unit. TEST POINT VOLTAGES Test PointDC Voltage Alpha OneDC Voltage Alpha 7RDC Voltage Alpha 8R/8P 132.8V35V37V 227.8V29V31V 315V15V15V 4-32.8V-35V-37V 527.8V-29V-31V 6-15V-15V-15V 7N/A0.09V0.09V 8N/A0.10V0.10V 90.3V0.27V0.27V 103.4V3.2V2.9V 1132.8V35V37V 12-3V-2.7V-2.5V 1332.8V-35V-37V Between 14 & 153.0 -3.5mV3.0-3.5mV2.3-2.8mV 16 (protection off)0.0V0.0V 16 (protection on)0.6V0.6V 170.0V0.0V 180.0V0.0V 190.0V0.0V RadioFans.CN 收音机爱 好者资料库 H /P P SE MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL 3 Test PointDC Voltage Alpha OneDC Voltage Alpha 7RDC Voltage Alpha 8R/8P 200.0V0.0V0.0V 21 (protection off)1.6V1.6V1.6V 21 (protection on)5.0V5.0V5.0V 220.58V0.17V0.17V 233.4V3.1V3.1V 24-3V-2.7V-2.7V 25-26V-29V-29V Between 26 & 273.4mV3.4mV2.5mV 28 (muted)35V35V35V 28 (protection off)1V1V1V 29N/A5V5V 30N/A10.510.5V 31 (volume going up) N/A0V0V 31 (volume going down) N/A5V5V 32 (volume going up) N/A0V0V 32 (volume going down) N/A5V5V PARTS LISTS The parts for all the units are as the Alpha 7 except where shown. REFDescriptionPart NoProduct C1ELST 100U 100V2N710B7R C2PEST 47N 63V 10%2K3477R C3PCRB 100N 100V 5% RA 5mm 2H4107R C4PEST 47N 63V 10%2K3477R C5PSTY 33P 160V ENCAP 1PF% 2F0337R C7PPRO 4N7 63V 5% RA2D247N7R C8PPRO 100P 63V 5% RA2D110N7R C9ELST 100U 25V2N710A1 C10ELST 22U 20V OSCON2P6227R C10ELST 22U 63V ELECT2N622A1 C11ELST 100U 100V2N710B7R C12ELST 100U 100V2N710B7R C13PEST 15N 63V 10%2K3157R C14PEST 15N 63V 10%2K3157R C15SUPPR CAP 4N7 250V2K2477R C16ELST 100U 25V2N7107R C17CERD 470P 63V 20% RA2A1477R C18CERD 1N0 63V 20% RA2A2107R C19ELST 100U 25V2N7107R C20CERD 470P 63V 20% RA2A1477R C21CERD 10N 63V 20% RA2A3107R C22CERD 10N 63V 20% RA2A3107R C23SUPPR CAP 4N7 250V2K2477R C24PPRO 4N7 63V 5% RA2D247N7R C25PCRB 100N 100V 5% RA 5mm 2H4107R C26PCRB 100N 100V 5% RA 5mm 2H4107R C27ELST 220U 16V2N7227R C28PCRB 100N 100V 5% RA 5mm 2H4107R H /P P SE MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL 4 C29ELST 1U0 50V 20% RA2N5108R C30ELST 22U 63V ELECT2N6227R C30ELLL 47U 10V ELECT2R647A1 C30ELEC 10U 25V CERAFINE2P610CC8R C101ELST 100U 100V2N710B7R C102PEST 47N 63V 10%2K3477R C103PCRB 100N 100V 5% RA 5mm 2H4107R C104PEST 47N 63V 10%2K3477R C105PSTY 33P 160V ENCAP 1PF% 2F0337R C107PPRO 4N7 63V 5% RA2D247N7R C108PPRO 100P 63V 5% RA2D110N7R C109ELST 100U 25V2N710A1 C110ELST 22U 20V OSCON2P6227R C110ELST 22U 63V ELECT2N622A1 C111ELST 100U 100V2N710B7R C112ELST 100U 100V2N710B7R C113PEST 15N 63V 10%2K3157R C114PEST 15N 63V 10%2K3157R C116ELST 100U 25V2N7107R C117CERD 470P 63V 20% RA2A1477R C118CERD 1N0 63V 20% RA2A2107R C119ELST 1U0 50V 20% RA2N5107R C120CERD 470P 63V 20% RA2A1477R C121ELST 1U0 50V 20% RA2N5107R C122ELST 100U 25V2N7107R C123ELST 100U 25V2N7107R C124PPRO 4N7 63V 5% RA2D247N7R C125PCRB 100N 100V 5% RA 5mm 2H4107R C126PCRB 100N 100V 5% RA 5mm 2H4107R C127ELST 220U 16V2N7227R C128PCRB 100N 100V 5% RA 5mm 2H4107R C130ELST 22U 63V ELECT2N6227R C130ELLL 47U 10V ELECT2R647A1 C130ELEC 10U 25V CERAFINE2P610CC8R C200CERD 1N0 63V 20% RA2A2107R C201SUPPR CAP 4N7 250V2K2477R C204ELST 10m 50V RA 32mm2N9107R C204ELST 6M8 35V RA2N868A1 C205ELST 10m 50V RA 32mm2N9107R C205ELST 6M8 35V RA2N868A1 C206PCRB 100N 100V 5% RA 5mm 2H4107R C207PCRB 100N 100V 5% RA 5mm 2H4107R C208PPRO 4N7 63V 5% RA2D247N7R C209PPRO 4N7 63V 5% RA2D247N7R C210ELST 10U 50V2N6107R C211ELST 10U 50V2N6107R C212CERD 10N 63V 20% RA2A3107R C213CERD 10N 63V 20% RA2A3107R C214CERD 10N 63V 20% RA2A3107R C215CERD 10N 63V 20% RA2A3107R C216CERD 10N 63V 20% RA2A3107R C217CERD 10N 63V 20% RA2A3107R C301CERD 10N 63V 20% RA2A3107R C302CERD 10N 63V 20% RA2A3107R C502PCRB 100N 100V 5% RA 5mm 2H410A1 C303CERD 1N0 63V 20% RA2A2107R C304CERD 1N0 63V 20% RA2A2107R C305CERD 47P 63V -20% +80% RA 2A0477R C306CERD 47P 63V -20% +80% RA 2A0477R C401ELST 10U 50V2N6107R C402PEST 220N 63V 10%2K4227R C402PCRB 100N 100V 5% RA 5mm 2H410A1 C403PCRB 100N 100V 5% RA 5mm 2H410A1 C403PEST 220N 63V 10%2K4227R C404PPRO 4N7 63V 5% RA2D247N7R C4042N2 PP2D222A1 C405ELST 10U 50V2N6107R C406CERD 100P 63V 20% RA2A1107R C407CERD 100P 63V 20% RA2A1107R C408CERD 10P 63V 20% RA2A0107R C501ELST 10U 50V2N6107R C502PEST 220N 63V 10%2K4227R C503PEST 220N 63V 10%2K4227R C503PCRB 100N 100V 5% RA 5mm 2H410A1 C504PPRO 4N7 63V 5% RA2D247N7R C5042N2 PP2D222A1 C505ELST 10U 50V2N6107R H /P P SE MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL 5 C506CERD 100P 63V 20% RA2A1107R C507CERD 100P 63V 20% RA2A1107R C508CERD 10P 63V 20% RA2A0107R C601PPRO 100P 63V 5% RA2D110N7R C602CERD 47P 63V 20% RA2A0477R C603ELST 22U 63V2N6227R C604PPRO 4N7 63V 5% RA2D247N7R C605PPRO 1N3 63V 5% RA2D213N7R C606ELST 10U 50V2N6107R C701PPRO 100P 63V 5% RA2D110N7R C702CERD 47P 63V 20% RA2A0477R C703ELST 22U 63V2N6227R C704PPRO 4N7 63V 5% RA2D247N7R C705PPRO 1N3 63V 5% RA2D213N7R C706ELST 10U 50V2N6107R C801PPRO 100P 63V 5% RA2D110N7R C802PPRO 100P 63V 5% RA2D110N7R C803ELST 10U 50V2N6107R C804ELST 10U 50V2N6107R C805CERD 10N 63V 20% RA2A3107R C806CERD 10N 63V 20% RA2A3107R C901CERD 10N 63V 20% RA2A3107R C902ELST 220U 16V2N7227R C903CERD 10N 63V 20% RA2A3107R C904CERD 10N 63V 20% RA2A3107R C905CERD 10N 63V 20% RA2A3107R C906CERD 10N 63V 20% RA2A3107R C907ELST 1M0 25V2N8107R C1000CERD 10N 63V 20% RA2A3107R CL1ALPHA AMP 7/8 HEATS NK CLAMP E822017R CL2ALPHA AMP 7/8 HEATS NK CLAMP E822017R D1RECT FIER 1N4003F 1A 200V 3B40037R D2ZENER 10V 400MW3C110047R D3ZENER 10V 400MW3C110047R D4ZENER 10V 400MW3C110047R D5SSDIODE 1N4148 75V3A41487R D6RECT FIER 1N4003F 1A 200V 3B40038R D7SSDIODE 1N4148 75V3A41487R D8RECT FIER 1N4003F 1A 200V 3B40037R D9RECT F ER 1N4003F 1A 200V 3B40037R D10ZENER 5V6 400MW3C056048R D101RECT F ER 1N4003F 1A 200V 3B40037R D102ZENER 10V 400MW3C110047R D103ZENER 10V 400MW3C110047R D104ZENER 10V 400MW3C110047R D105RECT F ER 1N4003F 1A 200V 3B40037R D106RECT F ER 1N4003F 1A 200V 3B40037R D107RECT F ER 1N4003F 1A 200V 3B40037R D108ZENER 5V6 400MW3C056047R D201ULTRAFAST RECT F ER DIODE UF5403 3A 3B5403F7R D202ULTRAFAST RECT F ER DIODE UF5403 3A 3B5403F7R D203ULTRAFAST RECT F ER DIODE UF5403 3A 3B5403F7R D204ULTRAFAST RECT F ER DIODE UF5403 3A 3B5403F7R D801ZENER 5V6 400MW3C056047R D802ZENER 4V7 400MW3C047047R D803SSDIODE 1N4148 75V3A41487R D901RECT F ER 1N4003F 1A 200V 3B40037R D902ZENER 5V6 400MW3C056047R D903RECT F ER 1N4003F 1A 200V 3B40037R D904ZENER 5V6 400MW3C056047R D905SSDIODE 1N4148 75V3A41487R EL1FUSE CLIP WCK-180-01AF0627R FS201INS COVER PCB FUSEHOLDER F0227R FS201FUSE 20mm 1.25A ASC121267R FS201FUSEHOLDER 20mm PCB8S0047R FS202FUSEHOLDER 20mm PCB8S0047R FS202INS COVER PCB FUSEHOLDER F0227R HS1ALPHA AMP 7/8 HEATS NKE818017R HS1SIL PAD - 25 X 12.5mmE817MC7R HS1ALPHA AMP 7/8 HS CLIPE810MC7R HS2SIL PAD - 25 X 12.5mmE817MC7R HS2ALPHA AMP 7/8 HEATS NKE818017R HS2ALPHA AMP 7/8 HS CLIPE810MC7R HS3SIL PAD - 25 X 12.5mmE817MC7R H /P P SE MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL 6 HS3ALPHA AMP 7/8 HEATS NKE818017R HS3ALPHA AMP 7/8 HS CL PE810MC7R HS4S L PAD - 25 X 12.5mmE817MC7R HS4ALPHA AMP 7/8 HS CL PE810MC7R HS4ALPHA AMP 7/8 HEATS NKE818017R L1NDUCT 2U2 12x20mm7D002B7R L101NDUCT 2U2 12x20mm7D002B7R LED201LED RED/GREEN 5MM3D0027R LK19RES MF W4 3K3 1%1H2337R LK19AA8R AMP MBD TO AV SWITCH CABLE L835CA8R LK20RES MF W4 3K3 1%1H2337R LK3117-WAY RIBBON 250mmL825CA7R LK805JUMPER 3 WAY x 125mmL815CA7R LK901JUMPER 8-WAY LEADL809CA7R LK902JUMPER 3 WAY x 125mmL815CA7R MSMA NS SWITCH SPACERE669017R PCBPR NTED CIRCUIT BOARDL846PB7R Q1TRANS PWR MOSFET RF540/SMF045 4K0457R Q2TRANS PWR MOSFET RF540/SMF045 4K0457R Q3TRANS LF SS P BC556B4A5567R Q4TRANS LF SS N BC546B4A5467R Q5TRANS LF SS P BC556B4A5567R Q6TRANS LF SS P BC556B4A5567R Q7TRANS LF SS P BC556B4A5567R Q8TRANS LF SS N BC546B4A5467R Q9TRANS LF SS N BC546B4A5467R Q10TRANS LF SS N BC547B4A5477R Q11TRANS LF SS N BC547B4A5477R Q12TRANS LF SS N BC547B4A5477R Q13TRANS LF SS N BC547B4A5477R Q14TRANS LF SS P BC557B4A5577R Q15TRANS LF SS N BC546B4A5467R Q16TRANS LF SS P BC557B4A5577R Q17TRANS LF SS N BC546B4A5467R Q18TRANS LF SS N BC546B4A5467R Q19TRANS LF SS P BC556B4A5567R Q101TRANS PWR MOSFET RF540/SMF045 4K0457R Q102TRANS PWR MOSFET RF540/SMF045 4K0457R Q103TRANS LF SS P BC556B4A5567R Q104TRANS LF SS N BC546B4A5467R Q105TRANS LF SS P BC556B4A5567R Q106TRANS LF SS P BC556B4A5567R Q107TRANS LF SS P BC556B4A5567R Q108TRANS LF SS N BC546B4A5467R Q110TRANS LF SS N BC547B4A5477R Q111TRANS LF SS N BC547B4A5477R Q112TRANS LF SS N BC547B4A5477R Q113TRANS LF SS N BC547B4A5477R Q114TRANS LF SS P BC557B4A5577R Q115TRANS LF SS N BC546B4A5467R Q116TRANS LF SS P BC557B4A5577R Q117TRANS LF SS N BC546B4A5467R Q118TRANS LF SS N BC546B4A5467R Q119TRANS LF SS N BC546B4A5467R Q120TRANS LF SS N 2SC25474A25467R PL116 WAY DIL PIN HEADER8K63168P R1ARES MO 3W 5% 0R22 KOASPR3 1Q9227R R1RES MO 3W 5% 0R22 KOASPR3 1Q9227R R2RES CF W2 4R7 5%1D8477R R3RES CF W4 5% 2R21B8227R R4RES MF FU W3 100R 5% NFR25 1G1107R R5RES MF FU W3 100R 5% NFR25 1G1107R R6RES MF FU W3 100R 5% NFR25 1G1107R R7RES MF FU W3 470R 5% NFR25 1G1477R R8RES MF FU W3 470R 5% NFR25 1G1477R R9RES MF FU W3 470R 5% NFR25 1G1477R R10RES MF FU W3 470R 5% NFR25 1G1477R R11RES MF FU W3 470R 5% NFR25 1G1477R R12RES MF FU W3 470R 5% NFR25 1G1477R R13RES MF W4 1% 1K01H2107R R14RES MF W4 1% 1K01H2107R R15RES CF W4 5% 1K01B2107R R16RES MF W4 1% 2K71H2277R R17RES MF W4 1% 5K61H2567R R18RES MF W4 1% 2K71H2277R H /P P SE MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL 7 R19RES CF W4 5% 5K61B2567R R20RES MF W4 1% 15K1H3157R R21RES MF W4 1% 100R1H1107R R22RES MF W4 1% 120R1H1127R R23RES MF W4 1% 2K71H2277R R24RES MF W4 1% 2K71H2277R R25RES MF W4 1% 330R1H1337R R26RES MF FU W3 470R 5% NFR25 1G1477R R27RES MF FU W3 470R 5% NFR25 1G1477R R28RES MF W4 18K 1%1H3187R R29RES MF W4 1% 1K21H2127R R30RES MF W4 1% 33K1H3337R R31RES CF W4 5% 1K01B210A1 R32RES MF W4 1% 33K1H333A1 R33RES MF W4 1% 680K1H468A1 R34RES MF W4 1% 1K01H2107R R34RES MF W4 1K6 1%1H216A1 R35RES MF W4 1% 33K1H3337R R36RES MF FU W3 100R 5% NFR25 1G1107R R39RES MF W4 18K 1%1H3187R R40RES MF W4 1% 33K1H333A1 R41RES MF FU W3 470R 5% NFR25 1G1477R R42RES MF W4 1% 620R1H1627R R43RES MF W4 1% 22K1H3228R R44RES MF W4 1% 68K1H3687R R45RES MF W4 18K 1%1H3187R R46RES MF W4 1% 150R1H1157R R47RES MF W4 1% 4K71H2477R R48RES MF W4 1% 47K1H3477R R49RES CF 1W 330R 5%1E1337R R50RES CF