McIntosh MI254 4-channel power amplifier

The MI254 4-channel digital amplifier is a versatile multi-channel amplifier, ideal for use in 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 sophisticated digital switching amplifiers. They are combined with highly durable power supplies to deliver performance levels rarely achieved in distributed audio.

The amplifier has installer-friendly physical dimensions and can be mounted in a 2U rack using the included mounting hardware. As a highly efficient Class D amplifier, it does not require noisy cooling fans to maintain operating temperature.

The front panel has two blue McIntosh wattmeters that show the combined power of channels 1+2 and 3+4. Multi-colored LED indicators show the status of each channel. The rear panel has both a balanced and an unbalanced input for each channel, as well as 5-way binding posts for McIntosh speakers.

Features of the MI254:

• Loudspeaker Guard prevents loudspeakers from being overloaded.
• The Sentry Monitor short-circuit protection circuit turns off the output level before the current exceeds a safe operating level and automatically returns to normal mode when operating conditions return to normal.
• BUS inputs and outputs to easily split the stereo signal to multiple outputs and/or multiple amplifiers.
• The environmentally friendly power management system switches the device on/off if the input signal has not been detected within the set time.

Manufacturer's product page (EN)

Technical information:

• Power Output per Channel:
  • 250 Watts into 8 Ohms
  • 300 Watts into 4 Ohms
• Number of Channels: 4
• Total Harmonic Distortion: 0.025%
• S/N below rated output: 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

General:

• Circuit Configuration: Closed loop digital switching
• Circuit Design: Digital
• Output Type: Direct Coupled
• Meters: Yes
• Meter Light Switch: No
• Balanced Input: 4
• Front Panel: Glass with removable rack mounting ears
• Illumination: Direct LED
• Chassis Style: Black painted steel

Dimensions:

• Width: 44.45cm
• Height: 11cm
• Depth: 53.3cm
• Weight: 10.7kg