
PO WER AMPLIFIER
CONTENTS
Performance Specifications ........................................ 2
Notes ......................................................................... 2
Rear Panel .................................................................. 3
Section Location ........................................................ 4
Block Diagram ...................................................... 5 - 6
Interconnection Diagram ...................................... 7 - 8
Input Schematic and PCB.................................... 9 - 10
Daughter Schematic and PCB............................. 11 - 13
Amplifier Schematic and PCB ....................... 11 - 12, 14
SERVICE MANUAL
Power Supply Schematic and PCB..................... 15 - 18
Output Schematic and PCB............................... 17 - 18
Remote Switch Schematic and PCB ................... 19 - 20
Panel Lamp A Schematic and PCB..................... 19 - 20
Panel Lamp B Schematic and PCB ............................ 21
Meter A & B Schematic and PCB .............................. 22
Parts List ............................................................ 23 - 26
Exploded Views and Parts Lists .......................... 27 - 32
Repacking Instruction .............................................. 33

PERFORMANCE SPECIFICATIONS
Power Output
Minimum sine wave continuous average power output per
channel, both channels operating is:
100 watts into 2 ohm load
100 watts into 4 ohm load
100 watts into 8 ohm load
Power Output Mono Parallel
Miniumum sine wave continuous average power output is:
200 watts into 1 ohm, 2 ohm or 4 ohm load
Power Output Mono Bridge
Miniumum sine wave continuous average power output is:
200 watts into 4 ohm, 8 ohm or 16 ohm load
Rated Power Band
20Hz to 20,000Hz
Total Harmonic Distortion
Maximum Total Harmonic Distortion at any power level
from 250 milliwatts to rated power output is:
0.5% for 2, 4 or 8 ohm loads (Stereo)
0.5% for 1, 2 or 4 ohm loads (Mono Parallel)
0.5% for 4, 8 or 16 ohm loads (Mono Bridge)
Frequency Response
+0, -0.25dB from 20Hz to 20,000Hz
+0, -3dB from 10Hz to 70,000Hz
Sensitivity
2.5 Volts Unbalanced Input
5 Volts Balanced Input
A-Weighted Signal T o Noise Ratio
100dB
Intermodulation Distortion
Maximum Intermodulation Distortion if instantaneous
peak output does not exceed twice the rated output,
for any combination of frequencies from 20Hz to
20,000Hz is:
0.5% for 2, 4 or 8 ohm loads (Stereo)
0.5% for 1, 2 or 4 ohm loads (Mono Parallel)
0.5% for 4, 8 or 16 ohm loads (Mono Bridge)
Input Impedance
20,000 ohms Unbalanced Inputs
40,000 ohms Balanced Inputs
Wide Band Damping Factor
Greater than 18
Power Requirements
100 Volts ~ , 50/60Hz at 6.0 amps
110 Volts ~ , 50/60Hz at 5.5 amps
120 Volts ~ , 50/60Hz at 5.0 amps
220 Volts ~ , 50/60Hz at 2.5 amps
230 Volts ~ , 50/60Hz at 2.5 amps
240 Volts ~ , 50/60Hz at 2.5 amps
Note: Refer to the rear panel of the MC2102 for the correct
voltage.
Dimensions
Front Panel: 17-3/4 inches (45.08cm) wide, 10-1/8 inches
(25.72cm) high. Depth behind front mounting panel is 16
inches (40.64cm). Clearance required in front of the Front
Panel is 1 inches (2.54cm) for knobs.
Weight
88 pounds (40kg) net, 121 pounds (54.9kg) in shipping carton
1. The heavy lines on the schematic denote the primary
signal path.
2. Unless otherwise noted, all voltages indicated on the
schematics are measured under the following conditions:
a. AC input at 120 volts, 50/60Hz.
b. All voltages are +/-10% with respect to ground. A
high impedance (10 megaohm) voltmeter must be used.
3. Unless otherwise specified:
a. Resistor values are in ohms.
b. Capacitor values are microfarads (uF).
c. Inductor values are in microhenries (uH).
NO TES
4. On PC board drawings, Square pad indicates:
a. Polarized Capacitors - Positive
b. Diodes - Cathode
c. Others - Pin 1
5. WARNING
Parts marked with the symbol have critical
characteristics. Use only replacement parts recommended by the manufacturer.
2

SECTION LOCATIONS
BOTTOM VIEW WITH COVER REMOVED
4

PARTS LIST
MC2102
Reference No.
Description
Part No.
INTERCONNECT
C1 C2 DISC CAP 0.0047MF 06127600
F1 FUSE 6.3A 250V SLO BLO IEC 08910400
L1 CHOKE, FILTER 0.5H 800MA 12233700
M1 M2 METER, OUTPUT 12407900
SW1 SW2 SWITCH, METER/POWER 2P3T 14625300
T1 T3 OUTPUT TRANS (LESS DECAL 126714) 04959000
T2 POWER TRANS (LESS DECAL 126713) 04959100
049508 INPUT
C1 C2 C3 C4 C5 C6 CAP ELECT 4.7UF 50V 06651200
D1 D2 D3 D4 D5 D6 D7 DIODE SILICON 07004700
J1 J3 CONN 4 PIN 11721500
J2 J4 J6 CONN MALE 5 PIN 11721600
J5 RECEPTACLE 9 POSITION 11772200
K1 K2 K3 K4 K5 K6 K7 K8 RELAY REED FORM 1A 5V 500 OHMS 08705000
K9 RELAY REED FORM 1C 5V 125 OHM 08705600
R5 R6 RES NETWORK 47KX6 14445800
049507 DAUGHTER
C1 CAP POLYPROP .047UF 10% 250VDC 06436400
C2 CAP POLYPROP 1UF 20% 250VDC 06443300
C3 CAP ELECT 100UF 6.3V 06649800
C4 CAP DISC 22PF 500V 06129300
C6 C11 CAP ELECT 10UF 100V 06649200
C7 C8 CAP MPOLY 0.1UF 630VDC 06443100
C9 CAP ELECT 10UF 250V 06649300
C10 CAP ELECT 1000UF 16V NP 06650000
C12 CAP M POLY .47UF 5% 50/63VDC 06433300
J1 CONN MALE 5 PIN 11721600
J2 CONN 4 PIN 11721500
J3 J4 J5 RECEPTACLE 9 POSITION 11772200
K1 K2 RELAY REED FORM 1C 5V 125 OHM 08705600
Q2 TRANSISTOR N JFET 13222200
R1 R12 RES MF 1M 1/4W 14426900
R2 R6 RES MF 1.21K 1% 1/4W 14419100
R3 R7 R31 RES MF 100K 1% 1/4W 14411300
R4 RES MF 93.1K 1% 1/4W 14441700
R5 RES MF 221K 1% 1/4W 14442100
R8 R9 RES MF 18.2K 1% 1/4W 14418100
R13 RES MF 332 1% 1/4W 14444600
R14 RES MF 365 1% 1/4W 14407100
R15 RES MF 28K 1% 1/4W 14436700
R18 R19 RES MF 475K 1% 1/4W 14436400
R20 R21 RES MF 1.5M 1% 1/4W 14442200
R22 RES MF 40.2K 1% 1/4W 14410700
R23 R24 RES MF 825K 1% 1/4W 14446000
R25 RES MF 200K 1% 1/4W 14411700
R26 R27 RES MF 61.9K 1% 1W 14445500
R28 RES MF 47.5K 1% 1/4W 14410800
R29 RES MF 100 1% 1/4W 14419600
R30 RES MF 66.5K 1% 1/4W 14445600
R32 POT TRIMMER 100K OHM 20% 13438300
R33 POT TRIMMER 2K OHM 20% 13438400
R36 RES MF 2.74M 1/4W 14427100
R37 RES MF 10K 1% 1/4W 14405300
049517 AMPLIFIER
C1 CAP POLYPROP 1UF 20% 250VDC 06443300
C2 C3 CAP POLYPRP 0.22UF 20% 1000VDC 06443200
C4 C5 C8 CAP ELECT 10UF 250V 06649300
C6 CAP DISC 22PF 500V 06129300
C7 CAP MONO 330PF 200V 10% NPO 06131100
C9 CAP ELECT 47UF 450V 06649700
D1 D2 D3 DIODE ZENER 200V 1.5W 07014600
D4 D5 DIODE RECTIFIER 07013100
J1 CONN MALE 6 PIN 11769800
J2 HEADER 9 CIRCUIT 11772400
J3 J4 J5 HEADER 9 POSITION 11772300
L1 L2 L3 L4 CHOKE 2.2 MH 12200100
R1 RES MF 100K 1% 1/2W 14442900
R2 R3 R6 R7 R21 RES MO 46-4K 1% 1W 14443600
R4 R5 RES MF 1M 1% 1/2W 14443200
R8 R9 RES MO 18K 5% 1W 14428600
R10 R11 R12 R13 RES MF 1K OHM 1% 1/2W 14430900
R14 R15 R16 R17 RES MO 220 5% 5W 14446300
R14 R15 R16 R17 L1 L3 SOLDER LUG .070 HOLE 07502000
R18 RES MF 22.1K 1% 1/2W 14442700
R19 RES MF 3.92K 1% 1/2W 14442400
R20 RES MO 10K 5% 2W 14443700
R22 RES MF 121K OHM 1% 1/2W 14430800
R23 RES MF 82.5K 1% 1/2W 14445900
V1 V2 V3 V4 SOCKET 9 PIN TUBE CERAMIC 17817000
V5 V6 V7 V8 SOCKET OCTAL TUBE CERAMIC 17816900
049509 POWER SUPPL Y
C1 CAP ELECT 22UF 100V 06650600
C2 CAP MPOLY 0.1UF 630VDC 06443100
C3 CAP POLY .047UF 10% 1000VDC 06443400
C4 C20 CAP ELECT 47UF 250V 06649600
C5 C6 C7 C8 CAP ELECT 1000MF 300V 06652000
C9 C11 CAP ELECT 2200MF 25V 06652200
C10 C21 C22 CAP ELECT 47UF 35V 06644600
C12 C25 C26 CAP M POLY .22UF 5% 63VDC 06432900
C15 C16 CAP M POLY 1UF 5% 63VDC 06433700
C17 C18 CAP MONO .1UF 50V 20% Z5U 06130500
C23 CAP ELECT 4.7UF 50V 06651200
C27 CAP ELECT 1UF 50V 06651000
C28 C29 CAP POLY 680PF 5% 160VDC 06429800
D1 D2 D5 D6 D19 DIODE SIL 400 PIV @ 1.5A 07003100
D3 RECT BRIDGE 400V/0.9A 07016800
D4 DIODE BRIDGE RECT 1000V 6A 07016500
D7 D8 D9 D10 D11 D12 D15 DIODE SILICON 07004700
D16 D20 D21 D22 D23 D24 DIODE SILICON 07004700
D25 D26 D27 DIODE SILICON 07004700
F1 FUSE 2A 250V SLO-BLO 5X20 IEC 08908800
F1 F2 HOLDER FUSE 5X20MM 17815900
F2 FUSE .25A 250V SLO-BLO 08905900
IC1 IC REGULATOR 12V 13315600
IC2 IC REGULATOR 5V 13325000
IC3 IC -5V REGULATOR 13325300
IC4 IC NAND SCHMIT 2-IN X 4 13319200
IC5 IC QUAD OP AMP TLC074CN 13341900
23
24

PARTS LIST con’t
Reference No.
J1 J2 J7 J8 J14 BLADE FASTON .187 11772600
J3 J4 J5 J9 J11 J12 CONN MALE 6 PIN PCB MOUNT 11769800
J6 HEADER 9 CIRCUIT 11772400
J10 CONN 8 POS MALE 11727500
J15 CONN MALE 7 PIN 11721700
J16 CONN 3 POS MALE 11729300
J17 CONN MALE 6 POS 11721800
J25 CONN MALE 3 POS 11721400
K1 RELAY 48VDC TV-8 08705200
OP1 TRIAC OPTOCOUPLER 13102400
Q1 TRANSISTOR P CHAN JUNCTION FET 13222600
Q2 Q5 TRANSISTOR NPN 13222300
Q3 Q4 Q6 Q7 TRANSISTOR NPN 13225400
Q8 Q9 TRANSISTOR N JFET 13222200
R1 RES WW 1.5K 10% 5W 13907900
R2 RES MET OXIDE 30K 5% 2W RES 14435300
R6 RES MF 22.1K 1% 1/4W 14418700
R7 RES MF 1K 1% 1/4W 14409000
R8 RES MF 10K 1% 1/2W 14442500
R10 R11 R40 RES MF 15K 1% 1/4W 14441200
R12 R13 R27 R45 RES MF 200K 1% 1/4W 14411700
R14 R15 RES MF 10K 1% 1/4W 14405300
R16 R43 RES MF 10M 1% 1/4W 14426400
R18 R19 RES MF 174K 1% 1/4W 14435200
R20 R21 POT TRIMMER 100K OHM 20% 13438300
R26 R35 R37 R44 RES MF 100 1% 1/4W 14419600
R28 R29 R46 R47 RES MF 3920 OHM 1% 1/4W 14419800
R30 R36 RES MF 1M 1/4W 14426900
R31 RES MF 68.1 1% 1/4W 14408200
R32 R33 RES CF 270K 5% 1/2W 14155100
R34 RES CF 10 5% 1/4W 14113600
R38 RES MF 95.3K 1% 1/4W 14412700
R41 R48 RES MF 2.74M 1/4W 14427100
R49 RES MF 1K OHM 1% 1/2W 14430900
RT1 RT2 SOLDER LUG .070 HOLE 07502000
RT1 RT2 THERMISTOR 5 OHM 14415100
Description
Part No.
049612 METER LAMP
DS1 DS2 DS3 DS4 DS5 DS6 LAMP INCANDESCENT 14V 100MA 05815300
J1 J4 CONN MALE 3 POS 11722100
J2 CONN MALE 3 POS 11721400
J3 CONN 4 PIN 11721500
MISC ITEMS
POST CARD SERVICE REPAIR 039594
OWNERS MANUAL 040742
TUBE 12AX7A 165065
TUBE 12AT7 165067
TUBE KT88 165069
LINE CORD SET 14GA VW1/PT2 170937
049510 REMOTE SWITCH/OUTPUT
C1 C2 POLYPRO 0.22MF 400V 20% 06443800
C3 C4 CAP ELEC 2.2UF 06651100
J1 HEADER 9 POSITION 11772300
J2 CONN MALE 6 POS 11721800
J3 BLADE FASTON .187 11772600
J4 CONN MALE 3 POS 11721400
J5 J6 HEADER 4 CIRCUIT POST 11777200
J7 J8 JACK MINI WITH NUT 11775800
R1 R2 RES WW 4 OHMS 5% 5W 13911900
S1 SWITCH SLIDE 2P3T 14807500
S2 SWITCH SLIDE DPDT 3MM 14807400
049646 P ANEL LAMP
DS1 LED RED HIGH EFFICIENCY 05814800
DS2 DS3 DS4 DS5 LAMP INCANDESCENT 14V 100MA 05815300
J1 CONN MALE 3 POS 11721400
J2 CONN 4 PIN 11721500
25
26

EXPLODED PARTS LIST
Item No.
1 016438 GLASS
2 049595 KNOB ASSY
3 104164 WASHER BLK FELT 1 X 1/4 X 1/16
4 018678 BOTTOM EXTRUSION
5 101172 SCREW TC 6-32 X 1/4 PH FL U/C
6 018585 TOP EXTRUSION
7 005144 EXTRUSION BRACKET
8 018615 END CAP 9”
9 101042 SCREW TS 4-40 X ½ SLOT FILLISTER
10 094016 TAPE FOAM 1/4 X 1/8
11 094360 TAPE FOAM 1/2 X 1/2
12 098113 DIAL CORD
13 017862 PUSH-ON FOOT
14 092434 FILTER METER
15 094017 TAPE FOAM 1/4 X 1/4
16 017839 PLEXIGLAS PANEL
17 124079 METER
18 092436 FILTER PALE BLUE
19 092435 FILTER AZURE BLUE
20 049646 PANEL LAMP PCB ASSY
21 100157 SCREW MACH 6-32 X 1/4 PHIL PAN
22 077025 SLEEVING FIBERGLAS #5
23 005134 SUBP ANEL
24 021159 BUSHING SWITCH
25 146253 SWITCH METER
26 052099 LIGHT BOX METER
27 102001 KEP NUT 4-40 CADMIUM PLATE
28 049612 METER PCB ASSY
29 101150 SCREW HI/LO 4-40 X 1/4 PHIL PAN
30 005137 MAIN PCB SHIELD
31 005154 DUST COVER BOTTOM
32 005153 DUST COVER SIDE
33 005152 DUST COVER TOP
34 126776 DECAL TOP COVER
35 005126 CHASSIS
36 165067 TUBE 12AT7
37 165065 TUBE 12AX7A
38 117487 RECEPT ACLE AC LINE
39 178161 FUSE HOLDER 5 X 20mm
40 117740 BINDING POST RED
41 117741 BINDING POST BLK
42 109018 SCREW MACH M2.5 X 0.45 X 5mm LONG
43 052104 CABLE ASSY RIGHT INPUT
44 052105 CABLE ASSY LEFT INPUT
45 100195 SCREW MACH 4 – 40 X 3/8 PH OVAL GLD
46 017761 AIR PIPE
47 100292 SCREW MACH 6-32 X 3/8 PH FH BLK
48 165069 TUBE KT88
49 005155 TUBE COVER
50 106055 CLIP TINNERMAN
51 101219 SCREW 6-32 X 5 TUBE COVER
52 049590 OUTPUT TRANSFORMER
Part No.
Description
53 049591 POWER TRANSFORMER
54 126714 DECAL OUTPUT TRANSFORMER
55 126713 DECAL POWER TRANSFORMER
56 049517 AMP PCB ASSY
57 017859 SPACER NYLON 6-32 X 7/16
58 101054 SCREW TAPTITE 6-32 X 1/4 PH PAN BLK
59 049507 DAUGHTER PCB ASSY
60 005135 CHASSIS SUPPORT
61 017801 RIVET PLASTIC
62 102006 NUT MACH W/LOCK
63 017860 SUPPORT PCB LOCKING
64 049509 POWER PCB ASSY
65 126524 DECAL FUSE REPLACEMENT
66 126527 DECAL FUSE
67 122337 CHOKE FILTER
68 102005 NUT MACH 8-32 W/LOCK
69 049508 INPUT PCB ASSY
70 005146 INPUT PCB BRACKET
71 049510 REMOTE SW/OUTPUT
72 104162 WASHER LOCK INTERNAL TOOTH
73 102051 HEX NUT M9 X .75 GOLD PLATED
74 104165 LW 3/8 INTERNAL GOLD TOOTH
75 104067 WASHER LOCK #10 INTERNAL STAR
76 104078 WASHER LOCK #8 INTERNAL STAR
77 005174 SWITCH SP ACER
78 017802 WIRE CLAMP
79 005151 BOTTOM COVER
80 101078 8-32 X 5/16 PH PAN BLK
81 017841 FOOT
82 100159 SCREW MACH 10-32 X 3/4 PH PAN BLK
83 024010 FOOT PAD
84 104016 WASHER LOCK 1/2 INT STAR
85 126250 DECAL GROUND
31
32

REPACKING INSTRUCTIONS
MC2102
POWER AMPLIFIER
33
SERVICE MANUAL
The continuous improvement of it’s products is the policy of McIntosh Laboratory Incorporated, who reserve the right to improve design without
notice. Because of the constant upgrading of McIntosh products’ circuitry and components, the Company cannot insure, and does not warrant, the
accuracy of the within schematic material, which is intended for information only.
McINTOSH LABORATORY, INC., 2 CHAMBERS STREET, BINGHAMTON, NEW YORK 13903 Printed in U.S.A. Part Number 040806