BRAND: Audio Research

SERIES: Reference 250SE Monoblock Power Amplifiers

TYPE: Power Amplifier

“When the brawn of the 250 SE is combined with its saturated tonal colors, huge dynamic swings, great transparency and delicacy, lifelike textures and solid- state-like low-bass extension and control, it is clear that this new amplifier is a world-class leader in the higher-power tube amplifier category.”

Don Saltzman, The Absolute Sound, January 2017


The Absolute Sound calls the Reference 250SE monoblock vacuum tube amplifier the “epitome of high definition”. From the moment the music begins, the foundation of an exceptional musical experience is evident. Sound emerges from an inky black background, revealing microdetails and performance cues typically reserved for the live performance. Substantial, authoritative bass underscores the event with control, speed, and textural accuracy. Space around performers and instruments rises before you creating a lifelike stage with scale and body. Dynamics swing from quiet passages to grand fortissimos without effort or strain. This is high definition listening. The REF 250SE amplifier concedes nothing in ultimate sound quality. An illuminated analog meter capable of displaying power output, line voltage or output tube bias takes center stage on the front panel. Underneath are buttons for fan speed, illumination level, biasing and the meter. Internally, the Reference 250 SE is supplied with carefully matched KT150 output tubes, custom designed capacitors, wiring and many other parts, and an immense and tightly regulated bulk power supply. Connections include accommodation for 4, 8 or 16 ohm speakers, an XLR input as well as 12 volt trigger connections. From the first note to the last, the exceptional experiential music is immersive. From an inky black background, details and performance cues emerge. Bass is substantive and underscored with cavernous resolution and textural accuracy. The soundstage around musicians and instruments expand in scale and body and paint a textural richness reserved for live performances. Control while maintaining finesse and musicality. After nearly 50 years, our focus remains the advancement of the state-of-the-art in music reproduction. Every component is meticulously hand-crafted and personally auditioned before it leaves our factory. Our attention to detail, customer service, and product support create unprecedented value. An Audio Research component is more than a purchase, it’s an investment. If you’re looking to make a statement, look no further than the Audio Research REF 250SE monoblocks. We invite you hear the difference by visiting your nearest Audio Research dealer for an audition.

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Power output
250 watts per channel continuous from 20Hz to 20kHz. 1kHz total harmonic distortion typically 0.5% at 250 watts, below .04% at 1 watt. Approximate actual power available at “clipping” 270 watts (1kHz).

Frequency response
(-3dB points at 1 watt) 0.5Hz to 110 kHz

Input sensitivity
2.4V RMS Balanced for rated output. (25.5 dB gain into 8 ohms)

Output taps
4, 8, 16 ohms

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



Tube complement

3 – Matched pair KT150 (Power output V1-6);
1 – Matched pair KT150 (Driver V7-8); 2 6H30 (Gain stage V9 and Regulator Driver V11);
1 – 6550C (Regulator V10)

Power requirement
105-130VAC 60Hz (210-250VAC 50Hz) 770 watts at rated output, 1000 watts maximum, 380 watts at “idle,” 1 watt off.

Width: 19” (48.3 cm)
Height: 8.75” (22.2 cm)
Depth:19.5” (49.5 cm)
Handles extend 1.5” (3.8 cm) forward

47 lbs. (21.3 kg) Net; 63 lbs. (28.6 kg) Shipping.