Specifications

92 dB with an "A" weighting network inserted, both
figures exceeding published limits of Mclntosh. Volume
control tracking was found to be accurate from left to
right channels within 0.2 dB from maximum settings
down to a -70 dB level
The action of the high and low cut filters is illustrated
in the 'scope photos of Fig 7 While the slope rates are
clearly only 6 dB per octave (we prefer steeper slopes
ourselves), Mclntosh wisely set the cut-off points at
sufficiently high and low frequencies (50 Hz for the
low-cut and 5 kHz for the high-cut) so that their intro-
Fig. 7 - Low-cut and high-cut filter response
duction into the signal path would not take too big a
"bite" out of musical content or program sources that
require "cleaning up" because of background hiss or
low frequency noise and rumble.
The action of the previously described loudness con-
trol is clearly illustrated in the three response plots
shown in Fig. 8. Note that these curves were achieved
with a constant setting of the master volume control
and only the loudness control setting itself was varied,
from one extreme to the other. Total level variation af-
forded by this control amounted to approximately 22
dB (each vertical division in this Figure as well as in
Figs. 4, 6 and 7 represents an amplitude difference of
10dB).
Use and Listening Tests
As is true of other Mclntosh components we have
tested in the past, one immediately senses that the C
27 is, first and foremost, a reliably built product and
one that is likely to last for a very long time and require
a minimum of servicing. Controls have a positive and
rugged feel about them and tend to be manipulated
with confidence even by an inexperienced user en-
countering the product for the first time. We played a
variety of discs through the phono section of the C 27,
using our recently acquired Shure V15 Type IV car-
tridge for that purpose. Our record library now contains
a good selection of direct-to-disc records which were
reproduced flawlessly through the C 27 and a high
quality 1 1 0-watt per channel power amplifier plus our
reference loudspeakers. Transient response was
superb and bass passages were tight and totally un-
muddied. Attempting to use the phone jack we
discovered that it must be powered from the intercon-
nections of the associated power amplifier. In other
words, the C 27, unlike the C 32, does not contain its
own built-in headphone amplifier but rather derives
phone power from the amp-speaker connections which
are brought over to the unit for the switching capability
incorporated in the C 27. A user of the C 27 would
want to utilize this feature in any case, and there is an
"off" position on the C 27's speaker switch for
headphone-only listening once these connections are
made-
All in all, Mclntosh seems to have come up with a
brand new preamplifier which should fit nicely into
those systems which are comprised of the finest power
amplifiers, speakers and program source components
and whose owners either prefer to do without such ex-
tras as graphic equalizers or expanders or who would
rather add such devices as separate accessories when
and if the need arises. In our opinion, the suggested
price of the new C 27 is not at all inconsistent with the
level of performance achieved by the C 27 or with its
excellent design, construction and control features.
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Fig. 8 - Action of separate loudness control at "flat"
(upper trace), "mid" and "max" (lower trace) settings