Усилители мощности стерео — McIntosh MI502

The McIntosh MI502 is a two-channel digital power amplifier designed for custom-installed audio systems. It uses closed loop digital switching technology and a 2U rack-mountable chassis whose mounting brackets can be removed when the unit is placed outside a rack. The black glass front panel carries dual blue McIntosh watt meters together with multi-color LED status indicators.

Key specs that matter

Output is 500 W per channel into 8 ohms and 800 W per channel into 4 ohms, and the FTC power rating is 500 W over a band of 20 Hz to 20 kHz. Harmonic distortion is given as 0.05 percent, with noise 98 dB below rated output. The dynamic headroom figure reads 2.7 dB into 8 ohms and 3.7 dB into 4 ohms. The damping factor exceeds 85 into 8 ohms and 45 into 4 ohms. Frequency response is held within +0 and -0.9 dB from 20 Hz to 20 kHz. The case measures 44.45 cm wide, or 48.3 cm with the brackets, by 10.9 cm high and 53.3 cm deep. It weighs 9.8 kg, and 17.2 kg when packed for shipping. McIntosh lists the circuit design as digital and the circuit configuration as closed loop digital switching, and the watt meters come fitted as standard rather than an option.

Engineering and use context

McIntosh lists several intended applications for the MI502 - the front left and right speakers of a home theater, a pair of in-wall subwoofers, outdoor speaker systems, or distributed audio throughout a house with several units stacked together. Inputs are provided in both balanced and unbalanced form, with one balanced input fitted, and the direct coupled outputs end in standard 5-way binding posts. Protection comes from Power Guard signal overload technology and from Sentry Monitor, a short-circuit protection that resets itself automatically once the fault clears. A 12V Power Control trigger lets a processor or preamplifier switch the MI502 on alongside other components, while on/off signal sensing lets the amplifier power itself up and down for eco-friendly operation. The front panel uses direct LED illumination, and the chassis is black painted steel.

Pairing

A surround processor or preamplifier with balanced outputs can drive the MI502 over XLR for the main pair of a home theater. The stronger 4 ohm figure leaves extra reserve for in-wall subwoofers or outdoor speakers.

Alternatives

The McIntosh MC462 is a two-channel solid state amplifier whose Autoformers let it deliver 450 W per channel whatever the speaker impedance.