Audio Research Reference 750 SEL Monoblock Power Amplifier

The Reference 750SEL monoblock amplifier is a full-scale vacuum tube design built to drive nearly any speaker with authority. Continuing the legacy of the Reference 600 it delivers over 750 watts per channel using sixteen KT150 power tubes and massive custom transformers. Its sound combines effortless power, deep controlled bass, vivid detail and expansive three-dimensional imaging. Designed for large listening rooms and demanding loudspeakers the REF750SEL creates a highly immersive musical experience, revealing subtle performance details against a quiet background while preserving scale, realism and emotional impact.

Technical Specifications: 

Power Output: 750 watts per channel continuous from 20Hz to 20kHz. 1kHz total harmonic distortion typically 0.5% at 750 watts, below .04% at 1 watt. Approximate actual power available at “clipping” 850 watts (1kHz). (Note that actual power output is dependent upon both line voltage and “condition” i.e. if power line has high distortion, maximum power will be affected adversely, although from a listening standpoint this is not very critical.)

Power Bandwidth: (-3dB points) 15Hz to 150kHz

Frequency Response: (-3dB points at 1 watt) 1 Hz to 200 kHz

Input Sensitivity: 4.6V RMS Balanced for rated output. (24 dB gain into 8 ohms)

Input Impedance: 200K ohms Balanced

Output Taps: 4, 8, 16 ohms

Output Regulation: Approximately 0.5dB 16 ohm load to open circuit (Damping factor approximately 17)

Overall Negative Feedback: 13dB

Slew Rate: 20 volts/microsecond

Rise Time: 1.5 microseconds

Hum & Noise: Less than 0.2mV RMS – 110dB below rated output (IHF-A weighted, input shorted, 16 ohm output)

Power Supply Energy Storage: Approximately 1300 joules

Power Requirements: 105-130VAC 60Hz (200-270VAC 50Hz) 2100 watts at rated output, 2400 watts maximum, 800 watts at “idle”

Tubes Required: 8 Matched pair KT150 Power Output; 1 6550WE Regulator; 1 6H30 Regulator Amplifier; 1 matched pair KT150 Driver; 1 6H30 follower.

Dimensions:

13.5″ (34.3 cm)
W x 23″ (58.4 cm)
H x 20.8″ (52.8 cm)
D. Handles extend 1.5″ (3.8 cm) forward and rearward

Weight: 170 lbs. (77.2 kg) Net; 395 lbs. (180 kg) per pair shipped weight