McIntosh MC 2100, Руководство пользователя

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TECHNICAL DESCRIPTION
A two stage preamplifier with three transistors in
each channel increases the input voltage 16 dB.
There are 13 transistors in each power amplifier sec-
tion. The two stage preamplifier is fed to a pair of
matched transistors arranged as an emitter coupled
amplifier with two inputs and one output. The signal
from the preamplifier section connects to one of these
inputs. Both AC and DC negative feedback are applied
to the other input. This large quantity of feedback is
used to reduce noise and distortion. The signal is then
fed to a voltage amplifier. The voltage amplifier is fol-
lowed by two driver transistors.
The output section is arranged as a series push-pull
amplifier. The power transistors used in the output
section of your MC 2100 are selected for their high
power dissipation capability, wide frequency response,
and large "safe operating area." In addition, each
power transistor is given four separate tests before it
is put in your MC 2100. This additional testing makes
sure your MC 2100 will deliver its rated power from
20 Hz to 20 kHz with low distortion and complete reli-
ability.
The power transistors are mounted on oversized
anodized heat sinks. The heat sinks assure that under
normal operation the transistors will operate at a low
temperature. If temperatures increase due to a shorted
speaker, or restricted ventilation, an automatic tem-
perature sensing device turns off the MC 2100. The
device operates automatically at a preset temperature.
The MC 2100 will turn on again when the temperature
has returned to normal limits. This additional feature
gives your MC 2100 complete reliability under the most
extreme operating conditions.
The output stages are matched to the load by the
Mclntosh autoformer. The Mclntosh autoformer is care-
fully wound using Mclntosh trifilar winding and inter-
leaving techniques. Trifilar winding and interleaving
gives the autoformers exceptional bandwidth. The
autoformers properly match the power transistors to
4, 8, and 16 ohm loads at all audio frequencies.
The use of the Mclntosh designed trifilar autoformer
makes the Mclntosh solid state amplifiers the only
amplifiers that deliver FULL POWER AT ALL SPEAKER
IMPEDANCES. You have not been power penalized for
your choice of loudspeakers when using the Mclntosh
MC 2100.
Another of the advantages of the autoformers is the
25 volt output for a constant voltage distribution sys-
tem. With the MC 2100 several sets of speakers can be
operated independently throughout your home.
To further insure reliability a special power output
SENTRY MONITORING CIRCUIT prevents failure of
the power output transistors due to excessive mis-
match of the output. When your MC 2100 operates nor-
mally the SENTRY MONITORING CIRCUIT has no
effect on signals passing through the power amplifier.
If the power dissipation should rise above normal op-
eration, the SENTRY MONITORING CIRCUIT restricts
the drive to the output transistors. The SENTRY MON-
ITORING CIRCUIT acts instantaneously for any input
signal or load combination. This arrangement assures
complete circuit reliability. Only Mclntosh gives you
this degree of protection.
There are three separate power supply sections. One
positive and one negative high current supply is used
for the output stages. The other positive supply is used
for the driving amplifier stages. All supplies are full
wave and use silicon rectifiers. Adequate filtering is
used to assure an absolute minimum of hum. The
power output stage filter capacitors have very high
capacity, which allows full power output below 20 Hz.
The power transformer is generous in size and runs
cool, even under heavy use.
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