Усилители мощности стерео — McIntosh MI347

The McIntosh MI347 is a seven-channel digital power amplifier built as a dedicated home theater amplifier. It relies on closed loop digital switching amplifiers paired with strong power supplies, and its understated exterior is designed either for rack installation or for open placement in a room. The channels are not all rated alike - three front channels carry more power than the four surround channels.

Key specs that matter

Front channels, three in all, each deliver 250 W into 8 ohms or 300 W into 4 ohms, while each surround channel is rated at 125 W into 8 ohms or 200 W into 4 ohms. The FTC power output rating is 250 W across a band of 20 Hz to 20 kHz. Harmonic distortion is 0.025 percent, with noise 100 dB under rated output. Peak headroom reaches 2.5 dB into 8 ohms and 3.5 dB into 4 ohms, and the damping factor exceeds 85 at 8 ohms and 45 at 4 ohms. Frequency response is flat within +0 and -0.9 dB between 20 Hz and 20 kHz. The chassis measures 44.45 cm wide, 48.3 cm with mounting ears, 15.4 cm high including feet and 53.3 cm deep, and weighs 14.8 kg, rising to 24.4 kg in its carton. Heat output is rated at 1500 BTU/h.

Engineering and use context

As a Class D design the MI347 runs without cooling fans. There are no meters, and channel status is shown by multi-color LEDs behind a glass front panel with direct LED illumination, while the chassis is black painted steel with removable rack ears. Each of the seven channels accepts balanced as well as unbalanced signals, and speakers connect through standard 5-way binding posts fed by direct coupled outputs. The circuit design is listed as digital. Bridged mono and parallel mono modes are not offered, and there is no multi-channel DB25 input. Protection includes Power Guard signal overload technology and Sentry Monitor short-circuit protection. Remote power control is supported, and signal sensing turns the amplifier on and off for eco-friendly operation.

Pairing

The split between three stronger front channels and four lower-powered surround channels matches a 7-channel home theater layout, with left, center and right speakers on the front channels and side and rear surrounds on the others. A surround processor with balanced outputs can feed all seven channels over XLR cables.

Alternatives

For stereo use, the McIntosh MI502 from the same digital range offers two higher-powered channels with blue watt meters.