McIntosh MI254 AC 4-channel digital power amplifier

McIntosh MI254AC

Digital surround power amplifier

The MI254 4-channel digital amplifier is a versatile multi-channel amplifier ideal for distributed audio, home theater or 2-channel stereo playback. It delivers 250 watts into 8 ohm speakers or 300 watts into 4 ohm speakers through its sophisticated digital power amplifiers. These amplifiers are paired with extremely robust power supplies that achieve performance levels rarely achieved.

It has rack-friendly dimensions and can be mounted in a 2U rack using the included mounting ears (the mounting ears can be removed for non-rack installations). As a highly efficient Class D amplifier, noisy fans are required to maintain rated operating temperature. As well as using distributed audio, the MI254 is ideal for home theaters to drive surround sound speakers and can be integrated into virtually any existing home theater system.

There are two blue McIntosh wattmeters on the front panel that show the summed power output of channels 1+2 and 3+4. Multicolored LED indicators show the status of each channel. The rear panel features balanced and unbalanced inputs for each channel, as well as our standard 5-way speaker terminals.

Other features of the MI254 include: Loudspeaker Guard signal overload technology that prevents speaker clipping; Our Sentry Monitor™ short-circuit protection circuit turns off the output stage before current exceeds safe operating levels, and then automatically resets when operating conditions return to normal. BUS inputs and outputs for easy distribution of a stereo signal to multiple outputs and/or multiple amplifiers; single canal entrances; 12 volt trigger capability; and eco-friendly on/off signal detection, which turns off the device if no input signal has been detected for a set period of time, or automatically turns on the amplifier when a signal is detected.

The MI254 incorporates many McIntosh design cues including a black glass front, blue wattmeters, an illuminated McIntosh logo and a familiar form factor highlighted by silver trim.

Technical specifications

Output power per channel:
250 watts into 8 ohms
300 watts into 4 ohms
Number of channels: 4
Total Harmonic Distortion: 0.025%
S/N under rated power: 100dB
Dynamic Headroom:
8 ohms: 2.5dB
4 ohms: 3.5dB
damping factor:
8 ohms: >85
4 ohms: >45
Rated power band: 20Hz to 20kHz
Frequency Response:
+0, -0.9dB from 20Hz to 20,000Hz

STEERING
Remote Power Control: Yes
Multi-channel DB25 cable: KA

CONNECTIVITY
Speaker Jacks Type: Standard

GENERAL SPECIFICATIONS
circuit configuration:
Closed digital circuit
Structure of the circuit: Digital
Mono Bridge: N/A
Mono parallel: KA
Output Type: Direct Coupled
Counter: yes
Counter light switch: no
Balanced input: 4
Front Panel: Glass with removable rack mounting ears
Lighting: Direct LED
Case Style: Black Painted Steel

WEIGHTS AND DIMENSIONS
Dimensions (W x H x D):
44.45 cm x (48.3 cm with mounting lugs) x 11 cm (4-5/16 cm) (including feet) x 53.3 cm (including front panel and cables)
Weight: 10.7kg
Shipping weight: 18.1 kg