Audio Database

The

McIntosh MC502 a price point -- unknown (1980 release)

Description
 
Stereo power amplifier of a compact size which the same design concept as C504 induced.

The lamp of Normal (green) in the front panel and Limit (red) is operating in the circuitry by the originality design called a "wave comparator."
If this circuitry compares an output wave with an input wave electrically and 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 will prevent amplifier carrying out clipping, and distortion will not be reproduced from a speaker, but a speaker will be protected safely simultaneously. Even in this case, amplifier demonstrates the rated maximum output. When amplifier overloaded, the light was switched on, and the Limit lamp is turned on between the grades which can be checked by the eye, even if the status of an overload is very short.
An input wave and an output wave are compared by IC operation amplifier, and the wave difference by distortion of an output wave is changed into a voltage. This voltage is amplified about 100 times and supplied to a Schmidt trigger circuit through a full wave rectifier circuit.

Rear
Internal

Rating of a mode
Form Stereo power amplifier
Output
Stereo : 72W+72W, an Output power (2.7ohm-4ohm)
50W+50W, an Output power (8ohm)
Monophonic recording : 150W, an Output power (8ohm)
Output-power band 20Hz - 20kHz
THD 0.02% or less (a stereo and a monophonic recording 20Hz - 20000Hz)
Frequency characteristic 20Hz - 20kHz, and +0 -0.25 dB
10Hz - 10kHz, and +0 -3.0 dB
SN ratio 95dB or more (at the time of an Output power)
Output voltage 25V
Dumping factor 50 or more
Input sensitivity/impedance 0.75V, 2.5V/75kohm
(It switches by a level control)
Power source AC100V, 50Hz/60Hz
Power consumption 20W-400W
Dimensions Front panel: Width 406x92mm in height
Main unit: Width 375x height 60x depth of 368mm
Weight 12.2kg