Specifications

Fig. 14 —Phono signal-to-noise plot, referred to 5 mV
input, 0.5 volts output
tained. Spectral distribution of the noise, in one-third
octave bands, is plotted in the frequency/amplitude
grid of Fig. 14. When we adjusted input and output
levels to correspond to the measurement method us-
ed by Mclntosh, (10 millivolts of input), a repeat of
the S/N measurement plot as shown in Fig. 1 5 yield-
ed a ratio of 91.9 dB, fully 2 dB better than claimed.
Fig. 15 —Same as Fig. 14, but using 10 mV input, per
Mclntosh specs
Signal-to-noise ratios obtained via the high-level
inputs (AUX 1, AUX 2 or Tape) were above 1 00 dB
and beyond the capability of this test instrument to
measure.
Distortion of the amplifier section of the MX 1 1 7
measured far below the minimum specification sup-
plied by Mclntosh. For an input level of 250 mV
(high level inputs) and an output of 2.5 volts, THD
measured 0.001 7% and 0.001 8% at 1 kHz for the
left and right channel outputs respectively. For a 20
Hz signal input, results were 0.005% and 0.0049%,
while for a 20 kHz input signal of the same ampli-
tude, the distortion readings were 0.003% for either
channel. Phono overload measured an acceptable
105 mV at 1 kHz. Overall frequency response was
down by - 1 dB at 1 4 Hz and 41 kHz, while the -3
dB points were observed as 1 0 Hz and 78 kHz.
Summary and Listening Tests
As usual, Mclntosh has come up with another fine
high fidelity component in the MX 1 1 7. The design
is extremely well balanced, so that all sections of the
product seem to work equally well. The FM tuner
section was very sensitive. The stations we normally
expect to receive with little audible background
noise (plus a few we don't often receive in "listen-
able" fashion) came through nicely and, we should
mention, that dial calibration was as close to perfect
as any we have seen-from one end of the dial to the
other. The AFL circuit, for all its fine "hold" on the
stations we tuned to did not prevent us from zeroing
in on weak stations that were located very close to
stronger ones-a complaint often lodged against less
sophisticated forms of AFC circuitry. Stereo separa-
tion was excellent and even when we expected to
hear background noise when tuning to certain
familiar weak stereo signals, the noise was far less
obtrusive than expected. This, no doubt, was thanks
to the automatic stereo noise suppression circuit
with its variable stereo separation circuitry.
The phono preamplifier circuitry produced no audi-
ble hum or noise even when reproducing extremely
soft passages from records having wide dynamic
range. Nor was there any evidence of overload dur-
ing peak groove excursions in audiophile records
which we auditioned on the MX 1 1 7. Bass reproduc-
tion was tight and completely unmuddied and open.
Treble tones were reproduced with no trace of
harshness or fuzziness and with excellent transient
signal clarity.
To all of these attributes must be added the
intangible qualities of durability, care in assembly,
and the almost-custom like craftsmanship which dis-
tinguishes all Mclntosh products from so many
others. Most Mclntosh equipment owners consider
these non-obvious qualities to be worth fully as
much, if not more, than the more obvious features
found in equipment made by their favorite hi-fi com-
ponent maker. Under those circumstances, what ap-
pears to be a relatively high price for this tuner-pre-
amplifier may be a bargain, after all.
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