McIntosh MX 113 Service Manual

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MX 113

AM / FM TUNER PREAMP

SERVICE INFORMATION

STARTING WITH SERIAL N0. IOOHI

McINTOSH LABORATORY INC. 2 CHAMBERS STREET BINGHAMTON. NEW YORK

SII XW

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MX 113 ELECTRICAL SPECIFICATIONS

AM TUNER SECTION
SENSITIVITY SELECTIVITY, ADJACENT CHANNEL

75pV IHF (external ant.) 35 dB minimum iHF in "NORMAL" Position.
b5 dB minimum IHF in NARROW" Position.

SIGNAL TO NOISE RATIO
IMAGE REJECTION
lIS dB iHF minimum; 55 dB at i00% modulation.
65 dB minimum 5140 kHz - I600 kHz.

HARMONIC DISTORTION
FREQUENCY RESPONSE
Does not exceed l% at 30% modulation.
3.5 kHz - 6 dB, "NORMAL" Position.
2.l kHz - 6 dB, "NARROW" Position.

FM TUNER SECTION

USEABLE SENSITIVITY SELECTIVITY
2.5 microvolts at IOO% modulation (:75 kHz ADJACENT CHANNEL:
deviation) for 3% total noise and harmonic
distortion iHF. 6 dB minimum IHF in "NORMAL" Position.
i5 dB minimum IHF in "NARROW" Position.
SIGNAL TO NOISE RATIO ALTERNATE CHANNEL:
70 dB below lOO% modulation. 58 dB minimum IHF in "NORMAL" Position.

88 dB minimum IHF in "NARROW" Position.

CAPTURE RATIO
SPURIOUS REJECTION
I.5 dB
90 dB IHF minimum.

HARMONIC DISTORTION
IMAGE REJECTION
Mono: Does not exceed 0.3% at i00%
modulation 175 kHz deviation. 95 dB minimum, 88 MHz - 108 MHz.

Stereo: Does not exceed 0.5%
STEREO SEPARATION

AUDIO FREQUENCY RESPONSE 35 dB at I,OOO Hz.

ii dB 20 Hz to I5,000 Hz with standard

de-emphasis (75 usec.) and 19,000 Hz scA FILTER

pilot Filter.

50 dB rejection from 67 kHz to 7l-I kHz.
275 dB per octave slope.
PREAMPLIFIER SECTION
FREQUENCY RESPONSE OUTPUT (tape)

10.5 dB, 20 Hz to 20,000 Hz. 0.25 volts with rated input. Phono input
signal of IO miiiivoits produces i.2 volts
output. FM and AM will produce I.2 volts

DISTORTION output at I00% modulation.

Less than O.l% at 2.5 volts 20Hz to 20 kHz.
OUTPUT (center channel)

INPUT SENSITIVITY (phono l and phono 2) 2 Volts with rated input to both channels.

2 miIlivolts for 2.5 volts output at 1 kHz.
BASS CONTROL

INPUT SENSITIVITY (aux, tape) -l8 dB to +l6 dB at 20 Hz.

0.25 volts For 2.5 volts output.
TREBLE CONTROL

HUM AND NOISE (phone I and phono 2) 120 dB to 20,000 Hz.
72 dB below l0 millivolt input.
LF FILTER
HUM AND NOISE (aux, tape) Flat or roll OFF below 50 Hz, down i2 dB
at 20 Hz.
85 dB below rated output.
HF FILTER

OUTPUT (main)
Flat or roll OFF above 5000 Hz, down l2 dB
2.5 volts with rated input. Up to lo at 20,000 Hz.
volts can be developed without distor-
tion. FM and AM will produce up to lo
volts output at 100% modulation.