McIntosh MC-2105 User manual

FROMSERIAL NO. 10M01 TO 26M07
MclNTOSHLABORATORYINC.2 CHAMBERSSTREETBINGHAMTON,NEWYORK
MC
2105

ELECTRICALSPECIFICATIONS
POWEROUTPUT:
105RMSwattscontinuousperchannelinto4,8,or16ohms
bothchannelsoperating.
HARMONICDISTORTION:
Lessthan0.25%at105wattspoweroutputfrom20Hzto20
kHz,bothchannelsoperating.Typicalperformanceisless
than0.1%atratedpower.Distortiondecreasesasoutput
isreduced.
INTERMODULATIONDISTORTION:
Lessthan0.25%ifinstantaneouspeakpoweroutputis210
wattsorlessperchannelwithbothchannelsoperatingfor
anycombinationoffrequencies20Hzto20kHz.
FREQUENCYRANGE:
20Hzto20kHz+0,-0.1dBatratedpower.
15Hzto60kHz+0,-0.5dBatratedpower.
10Hzto100kHz+0,-3.0dBatratedpower.
NOISEANDHUM:
90dBormorebelowratedoutput.
OUTPUTIMPEDANCE:
4,8,and16ohms
OUTPUTVOLTAGES:
25volts(connectto8 ohmoutputs.)
DAMPINGFACTOR:
18at4 ohmsoutput
13at3 ohmsoutput
10at16ohmsoutput
INPUTIMPEDANCE:
200,000ohms
INPUTSENSITIVITY:
0.5volts.Levelcontrolprovidedforhigherinputvoltage.
POWERREQUIREMENTS:
117voltsAC50-60Hz,90wattsatzerosignaloutput,450
wattsatratedoutput.

INPUTSECTIONPRINTEDCIRCUIT BOARD 043-795
LOCATIONOFTRANSISTORSNOTONPRINTEDCIRCUITBOARDS

INPUTSECTION
MC 2I05 154-292
INPUT SECTIONPRINTEDCIRCUITBOARD 043-795
HEAVYLINESHOWSPRIMARYSIGNALPATH

LEFTCHANNEL
POWEROUTPUTSECTIONPRINTEDCIRCUITBOARD 043-805
RIGHTCHANNEL
POWEROUTPUTSECTIONPRINTEDCIRCUITBOARD 043-805

POWER
OUTPUT
SECTION
154-
366
MC
2105

METERSECTION
MC 2105 154-294
METERSECTIONPRINTEDCIRCUITBOARD

SCHEMATICNOTES
1.Unlessotherwisespecified:Resistancevaluesareinohms,1/2watt,and10%tolerance;
capacitancevaluessmallerthan1 areinmicrofarads(µf); capacitancevaluesgreater
than1 areinpicofarads(pF);inductorsareinmicrohenries(µH).
2. Printed circuit board components are outlined onthe schematics by dotted lines. The
circled numbers onthe dotted lines correspond tothe numbers onthePC board layouts.
I3.Theheavylinesontheschematicsdenotetheprimarysignalpath.
4.Theterminalnumberingofrotaryswitchesisforreferenceonly.
5.Allvoltagesindicatedontheschematicsaremeasuredunderthefollowingconditions:
a.Useofan11megohmimpedanceVTVM.
b.Allvoltages±10%withrespecttochassisground.
c.Hosignalatinputterminals.
d.ACinputat117voltsAC,50/60Hz.
e.Frontpanelcontrolsat:
LeftGain
MeterRange
RightGain
Speakers
Power
FULLYCCW
OFF
FULLYCCW
ON
OH
6.R125,R126,R127,andR128are2.7Kinearlyunits.
7.R215andR216are1.2KandR217andR218are22Kinearlyunits.
8.In units with serial No'sbelow 10M40: C111, C112,C113, and C114, are used;C107,C108,
C109.andC110(partNo.064-044)are.047;TheemitterofQ113andQ114isconnectedas
shown bythe dotted line; R139 and Rl40 {part Ho. 139-061) are used.
9.In unitswith serial No'sbelow11M93:Rl59 and R160 arenot used;R143, R144, R145,R146,
R147,R148,R149,andR150are.15W(partHo.139-055);pinsHo.12and9 onPCboards
are connected as shown by dotted line.
10. C125 and C126 are used in units with serial No's from 11M93 to 13M05.
11.R137fR138,R141,andRl42are75ohm9W10%(partNo.139-070)andR119andR120are2751
inearlyunits.
12.In units with serial No's below 20M01; R107,R108,C105, and C106 are used; ferrite beads
(partNo.076-010)arenotused.
13.In units with serial No's below 20M50 R161 and R162 arenot used andpinl4is
connected as shown by dotted line.
14. R155 and R156 are 8.2ohm 10%in units with serial No's from l0M40 to 21M13.
15. R109, 110is47Kin units with serial No's from 11M93 to 23M25.
16.In units with serial No'a below 10M40; C117 and Cll8 are .0012. In units with aerial
No'sfrom10M40to23M25,C117andCll8arenotused.
17.In units with serial No'sbelow 23M25, C115 and C116 are .0012.
18.AdjustmetercalibrationcontrolsR213(leftchannel)andR214(rightchannel)so
outputmetersindicate+3dBwhenmeterrangeswitchisinthe"0"positionandthe
amplifierisdelivering105wattsoutput.
METERSECTIONPRINTEDCIRCUITBOARD043-711

REPLACEMENTPARTS
All parts not listed are common items obtain-
able from radio parts jobbers.
Replacement parts maybe obtained when ordered
byPARTNUMBERfrom:
MclntoshLaboratoryInc.
CustomerServiceDepartment
2 Chambers Street
Binghamton,HewYork13903
(telephone[phone])
CAPACITORS
Symbol
NumberDescription
C1,2Mylar,22uF250V
C3,4Mylar.47uF250V
C5,6Elect.500uF16V
C9,10Elect.l0uF25VNP
C11,12Elect.100uF15V
C101,102Elect. 330uF 3V
C121,122Elect.10uF50V
C201,202Mylar..47uF250V
C203,204 Elect. 100uF 3V
C301Elect.39,000uF40V
C302 Elect. 39,000uF 40V
C303 Elect.80/80/l50/50uF
200/200/150/150V
DIODES
D101,102Si. signaldiode
D103,104Si.referencediode
Dl05,106Si.signaldiode
D107,108Si. signaldiode
D201,202Ge.signaldiode
D203,204Ge.signaldiode
D301,302RectifierAssy(Black)
D303,304RectifierAssy(Red)
D305 Si. rectifier
D306 Si. rectifier
PUSES
P301Fuse5 ampereSlo-Blo
CHOKES
L101,102Choke75uH
METERS
M201,202Meter(powerlevel)
Part
Number
064-043
064-045
066-107
066-005
066-127
066-105
066-113
064-045
066-047
066-119
066-119
066-095
070-022
070-040
070-022
070-022
070-003
070-003
043-903
043-904
070-031
070-031
089-007
122-013
124-013
Q1,2
Q3,4
Q5,6
Q101,102
Q103,104
Q105,106
Q107,108
Q109,110
Q111,112
Q113,114
Q115,116
Q115,116
Q117,118
Q117,118
Q119,120
Q119,120
Q121,122
Q121,122
Q123,124
Q123,124
Q125,126
Q125,126
Q201,202
R1,2
R213,2l4
R117,118
R137,138
R141, 142
R143,144
R145,146
R147,148
R149,150
R159-160
R301,302
-TRANSISTORS
Si.NPNtransistor
Si.NPNtransistor
Si.PNPtransistor
Si.PNPtransistor
Si.PNPtransistor
Si.NPNtransistor
Si.NPNtransistor
Si.PNPtransistor
Si.NPNtransistor
Si.PNPtransistor
Si.NPNtransistor
(Below Serial No. 20M01)
Si.NPNtransistor
(Above Serial No. 20M01)
Si.NPNtransistor
(Below Serial No. 20M01)
Si.NPNtransistor
(Above Serial No. 20M01)
Si.NPNtransistor
(Below Serial No. 20M01)
Si.NPNtransistor
(Above Serial No. 20M01)
Si.NPNtransistor
(Below Serial No. 20M01)
Si.NPNtransistor
(Above Serial No. 20M01)
Si.NPNtransistor
(Below Serial No. 20M01)
Si.NPNtransistor
(Above Serial No. 20M01)
Si.NPNtransistor
(Below Serial No. 20M01)
Si.NPNtransistor
(Above Serial No. 20M01)
Si.NPNtransistor
POTENTIOMETERS
Gaincontrols
Metercalibrationadjust
RESISTORS
Wirewound3.6K5%5W
Wirewound.56ohms5W
Wirewound.56ohms5W
Wirewound.33ohms5W
Wirewound.33ohms5W
Wirewound. 33ohms5W
Wirewound. 33ohms5W
Wirewound.33ohms5W
Thermistor
132-054
132-054
132-031
132-031
132-031
132-515
132-021
132-032
132-038
132-039
132-518
132-541
132-518
132-541
132-517
132-541
132-517
132-541
132-517
132-542
132-517
132-542
132-054
134-191
134-120
139-065
139-061
139-061
139-071
139-071
139-071
139-071
139-071
144-012

31
S101
S201
S301
S302,303
T101,102
T301
SWITCHES
Inputcouplingswitch
Speakerswitch
Meterrangeswitch
Poweron-offswitch
Thermalcut-out
TRANSFORMERS
Outputtransformer
Powertransformer
FRONTPANELANDTRIM
Frontpanel
Frontpanelendcaps
Knobs(allcontrols)
LAMPS
#1866(forwording)
#1888(formeters)
PANLOCSYSTEM
Shelfbracket(right)
Shelfbracket(left)
Mountingtemplate#300
Hardwarepackage
MISCELLANEOUSITEMS
Plasticfeet
Shippingcarton
Ownersmanual
Linecord
148-006
146-103
146-109
146-102
153-007
043-649
043-693
043-735
018-112
043-253
058-014
058-029
043-678
043-679
038-161
043-691
017-041
043-793
038-163
170-021
5C01106S-M9321JG

SCHEMATICPART NO. 038-321