McIntosh MAC 1900, Руководство пользователя

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Using the Tuning Dial
TUNING DIAL
The MAC 1900 has three dial scales:
1. AM - Marked 55 to 160 kHz
2. FM-Marked 88 to 108 MHz
3. Logging scale - Marked 0 to 100
The logging scale can be used to accurately re-
tune any station. You may find it easier to keep a
record of your favorite stations by use of the logging
scale.
A small portion of dial pointer has been illumi-
nated to increase the ease of tuning.
INDICATORS
There are three indicators on the MAC 1900 dial
panel. They are: FM MPX indicator, SIGNAL
STRENGTH meter, and the TUNING meter.
STEREO INDICATOR (FM MPX)
The FM MPX indicator lights red when the dial
pointer is tuned to or crosses a FM station broadcast-
ing the 19,000 Hz carrier for stereo. The special cir-
cuit used will light only when the 19,000 Hz multiplex
carrier is present in the signal. The indicator will not
light on noise pulses or interference.
FM TUNING METER
An FM station is correctly tuned when the meter
needle is in the black area of the FM TUNING meter.
SIGNAL STRENGTH METER
When tuning FM the SIGNAL STRENGTH meter
indicates the strength of the signal as received from
the antenna. The higher the indication, the stronger
is the signal. For AM tune for the maximum indication
on the meter.
Using the Pushbuttons
MODE SELECTOR
Connects the program to the loudspeakers in the fol-
lowing seven ways:
STEREO: Connects the "left" input to the "left"
loudspeaker and the "right" input to the "right"
loudspeaker.
S. REV: Connects the "left" input to the "right"
loudspeaker and the "right" input to the "left"
loudspeaker.
MONO (L + R): adds the "left" input and the
"right" input and then connects the L + R pro-
gram to both amplifiers and loudspeakers.
L to L & R: Connects the "left" input to both loud-
speakers.
R to L & R: Connects the "right" input to both
loudspeakers.
L + R to L: Connects the "left plus right" pro-
gram to the "left" loudspeaker only.
L + R to R: Connects the "left plus right" pro-
gram to the "right" loudspeaker only.
LOUD:
The LOUDNESS control automatically provides the
correct amount of bass required to compensate for
the change in response of the human ear at low
loudness levels.
When the volume is reduced, the music will seem
to lose much of its bass and some of its treble. This
effect is due to the sensitivity characteristic of human
hearing. The response of the human ear to bass and
treble pitch decreases more rapidly than its response
to pitch centered in the mid-tonal range. The LOUD-
ness switch converts the volume control to a loud-
ness compensated control. Use LOUDness-IN to
listen at low volume and still hear full-frequency
range.
MONITOR
The MONITOR pushbuttons make it possible to
instantaneously compare recorded material with the
source signal from either of two tape recorders used
with the MAC 1900. The recorders used with the MAC
1900 should have separate record and playback
heads and separate record and play amplifiers.
When either TAPE MONITOR pushbutton is in the
MONITOR position a rectangle is lighted in the dial
area. When the light is on only the tape can be heard.
To listen to any other program source the light must
be off.
With the button pushed in, the signal source be-
comes the program as recorded and is fed through
the main preamplifier to the power amplifiers and
loudspeakers.
MONITOR TAPE 1: Connects the output from a tape
recorder that has its own playback electronics to the
high level input stages of the MAC 1900.
MONITOR TAPE 2: Connects the output from a tape
recorder that has its own playback electronics to the
high level input stages of the MAC 1900
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