Audio Database McIntosh MC2205 a price point -- unknown (release time -unknown) Description 　 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. To the 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. The 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 modification. 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 is carried. 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. Rating of a mode Form Stereo power amplifier Output stereo: 200W+200W (Output power) 14.1VRMS (at the time of a 1-ohm load intensity) 20.0VRMS (at the time of a 2-ohm load intensity) 28.3VRMS (at the time of a 4-ohm load intensity) 40.0VRMS (at the time of an 8-ohm load intensity) mono: 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 intensity) 28.3VRMS (at the time of a 2-ohm load intensity) 40.0VRMS (at the time of a 4-ohm load intensity) Output load impedance stereo: 1 ohm, 2ohm, 4ohm, 8ohm mono: 0.5 ohm, 1ohm, 2ohm, 4ohm Output-power band 20Hz - 20kHz THD (at the time of both ch(es) drive) 0.1% or less (Outputs 0.25W-200W, 20Hz - 20kHz) Cross modulation distortion 0.1% or less (at the time of an Output power) Frequency characteristic (at the time of 1W output) 20Hz-20kHz+0 -0.25 dB 10Hz-100kHz+0 -3.0 dB SN ratio 95dB or more (at the time of an Output power) Output voltage 25V Dumping factor stereo: 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 load intensity) 16 (at the time of an 8-ohm load intensity) mono: 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 load intensity) 16 (at the time of a 4-ohm load intensity) Input sensitivity/impedance 0.75V, 2.5V/100kohm The semiconductor used Silicon transistor: 49 pieces Silicon diode: 45 pieces IC: Eight pieces Power source 120V, 50Hz/60Hz Power consumption 70W (at the time of a non-signal) 550W (at the time of a maximum rating output) Dimensions Front panel: Width 411.2x181mm in height Main unit: Width 381x height 166.7x depth of 368.3mm Weight 38.6kg 44.0kg (at the time of an original packaging)