McIntosh MR80, Owner'S Manual

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Front Panel Information and
Use of Controls
The MR 80 Tuner has the most f l e x i b l e control
system ever designed in a stereo FM tuner. Correct
use of these controls will yield a higher level of per-
formance than previously possible with conven-
tional tuners.
VOLUME CONTROL AND AC POWER SWITCH
The VOLUME control has been precision tracked
throughout the listening range (0 to - 65 dB) for ac-
curate stereo balance.
It sets the output level of the VARIABLE OUTPUT
jacks and the front panel HEADPHONE jack. The
FIXED OUTPUT jacks are not a f f e c t e d by the posi-
tion of the VOLUME control. The AC power switch is
part of the VOLUME control. Turning the VOLUME
control f u l l y counterclockwise turns the AC power
off.
TUNING CONTROLS AND FREQUENCY DISPLAY
Frequency Display
The Frequency Display indicates the received fre-
quency to the nearest 100 kHz.
Tuning
There are four methods of tuning your MR 80.
Automatic selection of the tuning method is pro-
vided by touch sensors associated with each of the
tuning controls.
Manual Tuning
When power is applied to the MR 80, the circuitry
automatically selects the manual or knob tuning
control mode. Turning the tuning knob clockwise
will increase the received frequency. Counterclock-
wise decreases the received frequency.
Note: When the MR 80 is operated but is not con-
nected to any other device (preamp, power amp,
antenna, test equipment, etc.), there is a chance the
frequency display will blank out when tuning with
the main tuning knob. This is normal and can easily
be corrected by reversing the 120V AC line plug or by
connecting the MR 80 to any other equipment.
Auto Scan
AUTO SCAN is provided by two touch pads im-
mediately to the left of the tuning knob. These two
touch pads start the tuner searching for a new sta-
tion. The small arrow will light next to the pad
touched and indicate the direction of scanning. It
will scan in the direction chosen until it stops at a
station or reaches the end of the band. At the band
end the tuner will reverse its scan direction.
Preset 1, 2, 3 & 4
These touch pads located to the left of the fre-
quency display select one of the four preset sta-
tions. Just touch to operate. A small rectangle will
light above the pad indicating which preset has been
selected.
Remote SCAN
Remote SCAN of either the presets or all stations
is provided for as described under back panel infor-
mation.
INDICATOR LIGHTS
Three indicator lights are provided immediately to
the left of the preset touch pads. The uppermost
STEREO indicates when a stereo broadcast is being
received. The second, LOCK, indicates when the
tuner is locked to the station. The lock circuit in the
MR 80 is unique in that tuned frequency is locked to
the station, not to an internal standard as in the case
of many digital tuners. This allows the MR 80 to be
tuned to any frequency within the FM band and lock
on that frequency. Other digital tuners can only lock
on specific channel assignments. This lock circuit is
so powerful that it must be disabled in order to tune
the tuner. You will notice that the moment that you
touch any one of the tuning controls the lock light
extinguishes and only comes on when the station is
properly tuned. Once lock has been established it
will remain on even if the station being received
should drift up to 2 megacycles either side of the
center of the carrier. Thus, perfect tuning is always
assured. The third indicator light, FILTER, indicates
when the stereo noise filter is in operation. The in-
dicator lights are in three different colors: red for
STEREO, amber for LOCK, and green for FILTER.
SELECTIVITY SWITCH
Two degrees of IF selectivity are selectable by the
SELECTIVITY switch. The NARROW or normal posi-
tion provides adequate selectivity for stereo recep-
tion even under severe receiving conditions. Five
linear phase piezoelectric IF filters provide low
distortion reception with this high degree of selec-
tivity. Setting the SELECTIVITY switch to SUPER
NARROW adds an additional 4-pole 4-zero quartz
crystal filter to the five previously mentioned filters.
Use the SUPER NARROW position to receive sta-
tions from distant cities which are on channels adja-
cent to local stations. There may be useable signals
which were never heard before with ordinary FM
tuners.
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