||a price point -- unknown (release
Stereo power amplifier carrying a power meter. It
hits the power-meter loading model of MC2200.
Distortion is removed by
using the monolithic transistor differential amplifier with few noises for the
input side of a power amplifier circuitry. An input signal and a feedback signal
are supplied to this differential amplifier.
The circuitry of the following
stage is a voltage amplifying circuit of a Class-A operation, and a driver
circuitry and an output circuit adopt a complimentary scheme, carry out the
operation near a Class-A, and are reducing crossover distortion.
transition of a temperature, this circuitry is designed so that a moderate bias
may always start. A power transistor is AB class operation and, as for the bias
current, the safeness is maintained by the thermistor.
The para-push scheme of a single ended is used for an output stage, and
it consists of six reliable complimentary power transistors. For an equilibrium
nature Emitter-Follower join, a stability is good, and distortion's has
decreased and this circuitry has realized B class operation without crossover
distortion by adoption of a still more original output bias circuitry.
output signal of MC2205 passes an output transformer and is supplied to a
termination. Since this transformer is designed match the output-terminal of
every impedance, even if it uses which output-terminal, the maximum output is
obtained to all the signalling frequencies.
Moreover, the transformer
eliminated that component and this transformer has prevented the corruption of
the speaker, when it has a role which protects a speaker in the case of a
malfunction of amplifier and a direct current component mixes in an output.
In order to prevent an output transistor carrying out an overload, the
output signal is always supervised by the monitor circuitry of the mac
patent. This circuitry will become a high impedance if an Output voltage
becomes more than a rate, but this does not have influence on an output.
When an output becomes a upper, the signal supplied to an output transistor
by the monitor circuitry is restricted, and the output of amplifier short-circuits
or it prevents a corruption of an output transistor. This pilot circuit
is supervising separately the positive side output signal and the negative
side output signal.
The power guarding system which is an original new
circuitry is carried for the stability of play sound, and a tone-quality
In this circuitry, it has Normal (green) in the front panel, and the structure of operating by a wave comparator with a lamp of Limit (red)
original with a mac. This circuitry compares an output wave with an input wave
electrically, if that wave difference becomes 0.5%, a Limit lamp will light up
and a Normal lamp will go out. Moreover, if a wave difference reaches to 1%, the
power guarding circuitry will operate, it prevents amplifier carrying out
clipping, and distortion is not reproduced from a speaker, but a speaker is
protected simultaneously. Even in this case, amplifier demonstrates the rated
maximum output. An input wave and an output wave are compared by IC differential
amplifier, and the wave difference by distortion of an output wave is changed
into a voltage. Moreover, this voltage is amplified about 100 times and supplied
to a Schmidt trigger circuit through a full wave rectifier circuit.
A Limit lamp is turned on also when amplifier overloads. Even if the status
of an overload is very short, the light is switched on the time of the
grade which can fully be checked by the eye. In this case, meter displays
less than 200W. Also at this time, the voltage obtained from the wave difference
is used, and when it becomes higher than the level which makes a Limit
lamp turn on, a power guarding circuitry is operated.
When using a power guarding circuitry, the power
guarding switchpoint of a rear surface panel is set as the location of Normal.
When this switchpoint is in the location of out, only the Limit lamp operates.
The power meter which achieved the right-and-left channel independency
There is a tick mark of Watts and Decibels in meter, and if 0dB
or -20dB are used by switchover of a meter range, it will be displayed on the
tick mark of decibels.
||Stereo power amplifier
||200W+200W (Output power)
the time of a 1-ohm load intensity)
20.0VRMS (at the time of a 2-ohm load
28.3VRMS (at the time of a 4-ohm load intensity)
the time of an 8-ohm load intensity)
||400W (Output power)
14.1VRMS (at the
time of a 0.5-ohm load intensity)
20.0VRMS (at the time of a 1-ohm load
28.3VRMS (at the time of a 2-ohm load intensity)
the time of a 4-ohm load intensity)
|Output load impedance
||stereo: 1 ohm, 2ohm, 4ohm, 8ohm
0.5 ohm, 1ohm, 2ohm, 4ohm
||20Hz - 20kHz
|THD (at the time of both ch(es) drive)
||0.1% or less (Outputs 0.25W-200W, 20Hz -
|Cross modulation distortion
||0.1% or less (at the time of an Output
|Frequency characteristic (at the time of 1W
||20Hz-20kHz+0 -0.25 dB
||95dB or more (at the time of an Output
||16 (at the time of a 1-ohm load intensity)
50 (at the time of a 2-ohm load intensity)
30 (at the time of a 4-ohm
16 (at the time of an 8-ohm load intensity)
||16 (at the time of a 0.5-ohm load intensity)
50 (at the time of a 1-ohm load intensity)
30 (at the time of a 2-ohm
16 (at the time of a 4-ohm load intensity)
|The semiconductor used
||Silicon transistor: 49 pieces
diode: 45 pieces
IC: Eight pieces
||70W (at the time of a non-signal)
(at the time of a maximum rating output)
||Front panel: Width 411.2x181mm in height
Main unit: Width 381x height 166.7x depth of 368.3mm
44.0kg (at the time of an