Miles Technology MPR-450 RA

The MPR-450, designed for continuous use, is well-suited for A/V and multimedia systems, distributed sound, professional surround systems, commercial theater surround, installed home theater, and other multichannel applications where accurate sound, robust performance, and high reliability are desired.

Six independent channels deliver in excess of 450 continuous watts with audiophile fidelity. Each pair is bridgeable with the flip of a switch for higher power with three, four, or five channels.  Separate gain controls for each channel of the MPR-450 allow precise level adjustment for each loudspeaker.  Their position on the back panel prevents unauthorized changes.

The MPR-450's straight-path design yields clean, accurate, and dynamic sound.  The signal source is reproduced exactly as intended.  A heavy-duty, high-energy R-core power transformer provides exceptional efficiency.  This robust power supply, in combination with a special proprietary design, automatically sends extra power to channels where it's most needed.

Audiophile-quality sound is assured with a linear, straight-path, low-impedance design.  The massive power supply is closely coupled to the outputs.  Distances are short and conductors are large.  This high-current supply busing provides rock-solid power at each output stage.  The discrete circuit topology with high-power metal output transistors ensures maximum reliability and sonic integrity.

Large internal heatsinks, direct-contact transistor mounting, and active SOA protection make the MPR-450 thermally efficient and impervious to short circuits.  With prolonged operation at full power, the variable-speed, super-long-life fan keeps the MPR-450 running cool.

Specifications:

• Dynamic Output Power, 8 ohms: 6 channels: 100 W each
• Continuous Output Power:
  8 ohms: 1 channel: 90 W
  2 channels: 75 W
  6 channels: 60 W each
  
  4 ohms: 1 channel: 130 W
  6 channels: 75 W each
  
  8 ohms bridged:
  1 pair: 250 W
  3 pairs: 150 W each
• Load Impedance: Drives any load; 4 ohms to 8 ohms recommended
• Bridged: 8 ohms recommended.
• Frequency Response: 20 Hz to 20 kHz, +0/-1 dB
• THD + Noise: >0.05%, 1 kHz, at rated output
  >0.15%, 20 Hz to 20 kHz, at rated output
• Signal To Noise Ratio: 20 Hz to 20 kHz
  Unweighted: >100 dB
• Voltage Gain (each channel): off to 29 dB
• Input Sensitivity: 0.8 V for rated output
• AC Power: 120 V or 240 V, 50/60 Hz
• Idle power: 36 W
• Typical use max. power: 780 W
• Dimensions: 3.5" x 19" x 12.7" (8.9 cm x 48.3 cm x 32.3 cm)
• Weight: 25 lbs (11.4 kg) shipping weight
• Indicators:
  Power: Blue light on the front panel indicates that the unit is powered.
  Signal Presence: Green lights on the front panel for each channel indicate presence of output signal.
  Peak: Red lights on the front panel for each channel indicate the onset of clipping (moderate intensity) and audible distortion (bright intensity).
  Temperature: Yellow light on the front panel indicates maximum operation of the cooling system.
• Cooling System: Forced air on demand, intake from front vents. Long-life (rated over 20 years operation at full speed), low-noise fan. Temperature sensing at each heatsink.
• Normal: Fan idles at low speed.
• Warm Heatsink: Fan is triggered to high speed during high-level audio output at any channel.
• Hot Heatsink: Fan operates at full speed, and yellow temperature indicator lights, until heatsinks return to warm threshold.

Input/Output:

• Input Connectors: Gold RCA input connectors
• Input Impedance: 15K ohms differential
• Output Connectors: Heavy-duty binding posts/double banana jacks; accommodate up to 10-gauge cable.
• Output Impedance: 30 mOhms

Controls:

• Power: Rocker switch on the front panel for turning the unit on/off.
• Gain Controls: Controls on the rear panel allow the gain of each channel to be set independently.
• Bridging: Three switches on the rear panel allow each pair of channels to be bridged for a single channel with greater output power.