McIntosh C-22 Service manual

C 22

SERVICE INFORMATION

STARTING WITH SERIAL NO. 10A01

MclNTOSH LABORATORY INC. 2 CHAMBERS STREET BINGHAMTON, NEW YORK

C 22

ELECTRICAL SPECIFICATIONS

Frequency Response

+0.5 to -0.5 dB, 20Hz to 20,000Hz

Distortion

Less than 0.2% at 10 volts output
Less than 0.02% at 3 volts output

Input Sensitivity (phono 1, phono 2, tape head)

2 millivolts for 2.5 volts output at 1kHz

Input Sensitivity (Microphone)

2.5 millivolts for 2.5 volts output

Input Sensitivity (aux, tape, tuner)

0.25 volts for 2.5 volts output

Hum And Noise (phono 1, phono 2, tape head)

74 dB below 10 millivolts input

Hum And Noise (aux, tape, tuner)

85 dB below rated output

Output (main)

2.5 volts with rated input. Up to 10 volts
can be developed without distortion.

Output (tape)

0.25 volts with rated input. Phono input
signal of 10 millivolts produces 1.25 volts

output.

Output (L & R)

1.0 volts with rated input on both channels.

A level control adjusts output.

Bass Control

+20 dB at 20Hz

Treble Control

+20 dB at 20,000Hz

LP Filter

Flat or sharp cutoff below 50Hz (down 30 dB @ 20Hz).

HF Filter

Flat or sharp cutoff above 5000Hz (down 30 dB @ 20,000Hz).

Unless otherwise specified, resistance values are

in

ohms,

1/2

watt,

and 10%

values smaller than 1 are in microfarads (µF);

values greater than 1 are in picofarads (pF).

Resistors marked with * are 1/4W.

The terminal numbering of rotary switches and printed

circuit board wires is for reference only.

All voltages are measured under the following condi-

tions:

1. Use of an 11 megohm input impedance VTVM

2. All voltages ±10% with respect to ground

3. AC input at 117 volts, 50/60 cycles

4. No signal at input terminals

5. Front panel controls at normal positions

tolerance. Capacitance

PREAMP. SECTION

154 - 318

SCHEMATIC NOTES

1. In

2. C22's built before 1965 used circuit modules

3. In early units R76 thru R83 do not appear.

4. In early units C35 & 36 do not appear.

5. In early units R67 was 50 ohms.

early units

made by Erie Electronics. In 1965, we changed

to Sprague Electric Co. The Sprague modules

are electrically equivalent to the Erie modules
but differ mechanically. The newer Sprague
modules are used for replacement when servicing

early C22 units. For data on replacing the

old Erie modules with the Sprague modules, refer

to Mclntosh Service Bulletin #108.

C3 & 4

were

50µF.

POWER SUPPLY

154-317

REPLACEMENT PARTS

All parts not listed are common items obtain­able from radio parts jobbers.

Replacement parts may be obtained when ordered
by PART NUMBER from:

Mclntosh Laboratory Inc.

Customer Service Department
2 Chambers Street
Binghamton, New York 13903

(telephone [phone])

CAPACITORS

Symbol Part
Number Description Number

C3,4 Elect. 100 µF 3V 066-047
C29

Elect.

C30 Elect. 1000/40/20 /20µF 066-037

40µF

200V

25/200/35o/35ov

066-049

C31 Elect. 50/50/50 µF 066-033

C32 Elect. 1200/1200µF 066-029

D1,2 Se. rectifier 070-005
D3,4 Si. rectifier 070-014
D5,6 Si. rectifier 070-014

F1 Fuse 1 amp 089-002

350/350/300V

30/30V

DIODES

PUSES

CHOKES

L1 ,2 Choke 100 mH . 122-004

POTENTIOMETERS
R1, 2 Tape equal. (1/2 Dia. ) 134-059
R1, 2 Tape equal. (5/8 Dia. ) 134-186
R3,4 Bass trim (1/2 Dia. ) 134-059
R3,4 Bass trim (5/8 Dia.) 134-186

R5 Balance control 134--061
R6 Volume control 134-060
R7,8,9 Output level (5/8 Dia.) 134-186
R7,8,9 Output level (1/2 Dia. ) 134--059

RESISTORS
R16,17 Low noise 330K 5% 1W 144-005
R20,21 Low noise 1.8K 5% 1/2W 144-002
R46,147 Low noise 330K 5% 1W 144-005
R67 Wirewound 33 ohm 10% 5W 139-007
R74,75 Wirewound 7.5 ohm 10% 5W 139-010

S1
S2

S3

S4

S5

S6,7

S8

S9,10

S11
S12
S13

S14
S15

T1

SWITCHES

Tape jacks switch

Input selector switch

Tape switch

Comp. switch
Mode selector switch
Treble control switch
Loudness switch

Bass control switch

Rumble switch
H.F. filter switch
Power switch
Pilot lamp switch
Phase switch

TRANSFORMERS .

Power transformer

•

146-053

146-049
148-006
148-006

149-108
146-052
148-006
146-051
148-006
148-006
148-005
148-003
148-007

159-019

MOUNTING SYSTEM
Shelf bracket (right) 043-592
Shelf bracket (left) 043-593
Mounting template #100 038-179
Hardware package 043-448

MISCELLANEOUS ITEMS

Line cord 170-021

Fuse holder 178-001
Shipping carton 033-027
Owners manual 038-027
Plastic feet 017-041
Shorting plug 127-001

Indicator glass 016-036

Audio cable (6') 170-015
Audio cable (1 phone, 170-016

1 phono)

- - -

MODULES
Treble cut
Treble boost

Bass, upper
Bass, lower
Rumble filter
H.P. filter
Phono equalization

LAMPS
#334 (indicator)
Festoon (indicator glass)

FRONT PANEL & TRIM
Front panel
Front panel glass
End cap, right
End cap, left
Volume control knob
Mode selector knob

Input selector knob

Balance knob
Bass control knob
Tape jacks knob
Treble control knob
Rocker switch knob
Level set knob

130-016
130-017

130-018

130-019
130-020
130-021
130-026

058-003
058-033

043-359
016-034
018-043
018-044
043-253
043-253
043-253
043-253

O43-428
043-428
043-428

090-007
090-010

SCHEMATIC

PART

NO.

038-270

20C0425S6-8M270

Be122002