User manual MCINTOSH MC2505

[. . . ] PRICE $1. 25 MC25O5 SOLID STATE STEREO POWER AMPLIFIER MC2505 CONTENTS TECHNICAL DESCRIPTION LOCKING METERS P E R F O R M A N C E CHARTS CHARTS SPECIFICATIONS IN A HURRY INSTALLATION TYPICAL HOOKUP CONNECTING BLOCK DIAGRAM OPERATING GUARANTEE The Mclntosh "will to perfection" requires that we probe constantly into the unknown to bring the performance of our electronic equipment closer to perfection than ever before. This requires a constant and relentless search for low noise, broad band conservative design with an ever lower distortion factor. This is not required of ordinary equipment of average designs. It is, for us, a costly but worthwhile scientific and engineering effort. [. . . ] Set the "METER RANGE SWITCH" to the --20 position. Play the 1000 Hz test tone recorded on the CBS Test Record STR100 on your phonograph. Turn the "LEFT GAIN" control until the left meter indicates "0. " 4. Turn the "RIGHT GAIN" control until the right meter indicates "O. " 5. Write down the meter indication at each frequency as the record plays. Transfer the readings by frequency to the graph. The graph shows the ideal RIAA response curve using the CBS #STR100 test record. Compare your curve with the curve on the graph. A deviation of 3 dB from the ideal is acceptable. By making this check at regular intervals, (for instance, every 6 months) any deterioration in the cartridge or system will be quickly detected. IDEAL RIAA SYSTEM RESPONSE USING CBS STR 100 TEST RECORD 4 2 0 -2 -4 -6 -8 -10 R E L A T I V E OUTPUT LEVEL IN dB -12 14 -16 -13 -20 20 100 1k 10k 20k FREQUENCY IN Hz IDEAL RIAA SYSTEM RESPONSE USING CBS STR 100 TEST RECORD 4 2 0 -2 -4 -6 -8 -10 RELATIVE OUTPUT LEVEL IN dB 12 -14 -16 -18 -20 5 20 100 1k 10k 20k FREQUENCY IN Hz IDEAL RIAA SYSTEM RESPONSE USING CBS STR 100 TEST RECORD 4 2 6 0 -2 -4 -6 -8 -10 RELATIVE OUTPUT LEVEL IN dB -12 -14 -16 -18 -20 20 100 1k 10k 20k FREQUENCY IN Hz IDEAL RIAA SYSTEM RESPONSE USING CBS STR 100 TEST RECORD 4 2 0 -2 -4 -6 -8 -10 RELATIVE OUTPUT LEVEL IN dB -12 -14 -16 -18 -20 20 100 1k 100k FREQUENCY IN Hz 20k 7 TYPICAL PERFORMANCE DATA 70 POWER OUTPUT vs FREQUENCY 60 POWER OUTPUT RMS WATTS 50 40 30 20 10 0 10 100 1k 10k 100k FREQUENCY IN HERTZ HARMONIC DISTORTION vs POWER OUTPUT PERCENTAGE INTERMODULATION DISTORTION INTERMODULATION DISTORTION vs POWER OUTPUT PERCENTAGE HARMONIC DISTORTION 0. 6 0. 6 0. 5 0. 5 0. 4 0. 4 0. 3 0. 3 0. 2 0. 2 0. 1 0. 1 10 POWER OUTPUT IN RMS WATTS 100 20 Hz 2kHz 20kHz 10 POWER OUTPUT IN EQUIVALENT RMS WATTS 100 8 SPECIFICATIONS ELECTRICAL SPECIFICATIONS: POWER OUTPUT: STEREO-- 50 RMS watts continuous per channel into 4, 8, or 16 ohms both channels operating. HARMONIC DISTORTION: STEREO--Less than 0. 25% at 50 watts output from 20 Hz to 20 kHz both channels operating. Typical performance is less than 0. 1% at rated power. Distortion decreases as output power is reduced. INTERMODULATION DISTORTION: STEREO--Less than 0. 25% if instantaneous peak power output is 100 watts or less per channel with both channels operating for any combination of frequencies 20 Hz to 20 kHz. DAMPING FACTOR: 14 at 4 ohms output 27 at 8 ohms output 13 at 16 ohms output INPUT IMPEDANCE: 200, 000 ohms INPUT SENSITIVITY: 0. 5 volt. Level control provided for higher input voltage. POWER REQUIREMENTS: 117 volts AC 50/60 Hz, 75 watts at zero signal output. SEMICONDUCTOR COMPLEMENT: 26 silicon transistors. 27 silicon rectifiers and diodes. FREQUENCY RANGE: 20 Hz to 29kHz +0, -0. 1 dB at rated power. 15 Hz to 60 kHz +0, -0. 5 dB at rated power. 10 Hz to 100 kHz +0, -3. 0 dB at one-half of rated power. NOISE AND HUM: 90 dB or more below rated output. OUTPUT IMPEDANCE: STEREO--4, 8, and 16 ohms MECHANICAL SPECIFICATIONS: SIZE: 5-7/16 inches high, 16 inches wide, 13 inches deep. [. . . ] -- 0: In this position of the meter range switch, the amplifier will deliver 50 watts when the meter indicates +3 dB, with meter indication of "0, " the amplifier delivers 25 watts, with a meter indi- cation of -3 dB, the amplifier delivers 12½ watts; and a meter indication of -10 dB, the amplifier delivers 2½ watts. HEADPHONE Use the jack for low impedance stereo headphones. Any headphones with 4, 8, 16 ohms may be used with this jack. SPEAKERS OFF: The loudspeakers are turned off when the SPEAKER switch is in the OFF position. [. . . ]