McIntosh C-22-CE Owners manual

STEREO

PREAMPLIFIER

C22

C22

C22 OWNER'S MANUAL

INTRODUCTION

The C22 Commemorative issue preamplifier
and owner's manual are faithful reproductions
of the original, produced from 1963 through 1968.
A few changes were made to the original
preamplifier design to reflect technology ad­vances and contemporary system requirements.

Signal switching has been updated to Elec­tromagnetic switches. Close tolerance film
resistors and polypropylene capacitors add
precision to equalizer, filter and tone control cir­cuits. The tube complement retains the reliable
12AX7A for the amplifying stages. The cathode
follower output stages are changed to 12AT7's
to allow more current output to drive lower im-

GENERAL DESCRIPTION

The Mcintosh C22 Stereophonic Preamplifier
is a control center for any sterophonic sound
system. To increase your enjoyment of stereo
music, this control center does four jobs with
great precision.

First, The control center amplifies weak elec­trical impulses. Phono signals are amplified
1000 times, while high level signals are amplified
10 times. As a record rotates on the turntable,
undulations in the grooves move the pickup
stylus approximately one thousandth of an
inch, in any direction, from the rest position.
From this slight mechanical movement, the
pickup stylus generates a weak electrical im­pulse on the order of a few thoudsandths of a

volt. To amplify and preserve the information in
such a small electrical impulse, the finest
amplifier performance is required.
Second, Every sound system is used in a dif­ferent environment. The tone balance of the

music is affected by variations in the environ­ment. Also, people listening to the music have

varying ideas of correct tone balance. To com-

pedance loads. Balanced audio outputs are
added to take advantage of the greater noise
reduction capabilities of Balanced cables. A
built-in headphone amplifier provides head­phone listening.

This preamplifier is dedicated in remem­brance of the late Frank H. Mcintosh, founder
of Mcintosh Laboratory and co-inventor of the
Mcintosh Unity Coupled output circuit, which

provided the foundation for the forming of the

company. Mr. Mcintosh was president of Mcin­tosh Laboratory, Inc. from its inception in 1949
until his retirement in 1977.

pensate for these conditions, a high-quality tone
control center is needed.
Third, All stereophonic and monophonic phono
records, both domestic and foreign, are record­ed with specific frequency equalization. The
control center must accurately compensate for
this equalization introduced in the recording
process.
Fourth, programs can originate from several
sources such as tuners, records, tape recorders,
CD players, etc. A control center is needed to
select and switch these sources separately, or
in combination.

All these jobs are performed with excellence
by the C22.

Once you have enjoyed the outstanding per­formance of the C22, you will understand why
Mcintosh products have earned their reputation
as "THE BEST". Your Mcintosh C22 Stereo­phonic Control Preamplifier will give you years
of the finest possible performance, and will
become a highly valued part of your home music
system.

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TECHNICAL DESCRIPTION

The C22 Stereophonic Preamplifier combines
excellence with the ease of operation. The most
often used controls have large diameter knobs.
A new type of rocker switch is used for controls
with simple on-off functions. The C22 has an il­luminated front panel to provide convenient
reading under low level lighting conditions. The

Mode and Input Selector switch positions are

also illuminated.

The C22 circuit consists of three amplifier
sections in duplicate for left and right stereo
channels, together with a common power
supply. The first amplifier section is referred to
as the Phono Preamplifier and is used to amplify
and equalize signals from a moving magnet

phono cartridge. Skillful circuit layout, proper
grounding and adequate shielding reduce hum
to such a low level that it is virtually im­measurable. Extreme care in manufacturing
combined with low noise tubes, high specific
resistivity circuit boards and metal film resistors
results in extremely low noise levels.

The second amplifier section follows the main
volume control, making it impossible to overload
the high level input circuits. The same design
techniques as used in the phono preamplifier sec­tion, follow the main volume control, making it im­possible to overload the high level input circuits.

The same design techniques as used in the phono

preamplifier section ensure low noise and hum.
The BASS and TREBLE feedback type tone con­trols operate within this section. The tone controls
are multi-position switches with approximately
4dB change per step. Exceedingly low distortion
and precise control of frequency response con­tour are assured with this type of design.

The third amplifier section is the cathode
follower output. The sharp cutoff (18dB per oc­tave) RUMBLE and HF (High Frequency) filters
are also associated with this section. The
cathode followers drive the Unbalanced Main
Outputs, and the positive (+) Balanced Outputs.

Unity gain phase inverters drive the negative (-)
Balanced Outputs.

The power supply deserves special mention.
The power transformer is constructed with
grain oriented laminations and magnetic
shielding, for low external hum fields. Long life
full wave bridge rectifiers, filter capacitor sec­tionalizing and careful grounding add to the

hum-free, long life of the C22.

Special attention has been given to the
mechanical design. The C22 may be conve-

niently installed in furniture cabinets, custom
built installation or in an attractively finished

Mcintosh cabinet.

FRONT PANEL FACILITIES

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INPUT SELECTOR

Fig. 2 - INPUT SELECTOR Switch.

Select any one of eight program sources with

this switch.

1. TAPE
nected to the TAPE 1 input.

2. TAPE 2: A tape recorder with its outputs con­nected to the TAPE 2 input.

3. CD: A CD player or changer with its outputs
connected to the CD inputs.

4. TUNER: A stereo AM/FM tuner with its out­puts connected to TUNER inputs.

5. PHONO 1: A record player with MM cartridge
connected to PHONO 1 inputs.

6. PHONO 2: A record player with MM cartridge
connected to PHONO 2 inputs.

7. AUX 1: Any auxiliary high level output signal
such as a tuner or TV audio.

8. AUX 2: Same as AUX 1.

1: A tape recorder with its outputs con-

MODE SELECTOR

2. R TO L & R: Connects the "right" input to both
loudspeakers.

3. STEREO REV: Connects the "left" input to the
"right" loudspeaker and the "right' input to the
"left" loudspeaker.

4. STEREO: Connects the "left' input to the "left"
loudspeaker and the "right" input to the "right"
loudspeaker.

5. MONO (L + R): Adds the "left" input and the
"right" input and then connects the L + R pro­gram to both amplifiers and loudspeakers.

6. L + R TO L: Connects the "left plus right" pro­grams to the "left" loudspeaker only.

7. L + R TO R: Connects the "left plus right" pro­grams to the "right" loudspeaker only.

VOLUME

Fig. 4 - VOLUME CONTROL

Use the VOLUME control to regulate the combin­ed volume level of both channels. Turning the
VOLUME control clockwise increases volume level.

BALANCE

Fig. 3 - MODE SELECTOR Switch.

Use the MODE SELECTOR to:

Listen to normal stereo.
Reverse the left and right arrangement of

musical instruments.

Balance the amplifiers and loudspeakers in

a stereo system.

Listen to monophonic sound.
Listen through both loudspeakers to either

rack of a stereo program source.

Turn the MODE SELECTOR to:

1. L TO L & R: connects the "left" input to both
loudspeakers.

Fig. 5 - BALANCE CONTROL

Use the C22 BALANCE control to balance

unequal volume in the left and right channels

of a program source. The volume of each
speaker system relative to the other can be
varied. At the same time their combined volume
level is maintained.

LEFT: Turning the control to the left accents the
left channel by reducing the right channel
output.

RIGHT: Turning the control to the right accents
the right channel by reducing the left channel
output.

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