Audio Research Reference 75 SE Stereo Tube Amplifier - Complete Set

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One of our favorite modern tube amps providing enough power for most speakers.

Not too heavy, not too hot, just the right amount of everything.

This is capable of outperforming the highly regarded McIntosh MC-275, in a much much more attractive form factor.

The brushed aluminum chassis and the blue backlit meters provide a refined laboratory instrument look, worthy of a well decorated living room without offending a significant other.

This particular sample is a one owner unit, lightly used, and will come to you complete with everything that would have come from the factory.

Your experience opening and setting up this unit will be very close to having a fresh unit that was just produced.

We's also extend a 6-month SkyFi warranty on this item.

Just bring it back to us and we will take care of anything that does not involve beer spillage, or crazy cats.

More from Audio Research:

The Reference 75 SE is a stunning amplifier in every way – performance, styling and reliability combined to elevate your music listening to a new experience. Capable of controlling a wide variety of speakers, the Reference 75 SE will transport you into the musical performance unlike any other comparable amplifier.

At the heart of the Reference 75 SE is decades of proven Audio Research vacuum tube technology, a legacy unrivaled by any other manufacturer of tube electronics. Developed through hundreds of hours of critical listening, the carefully selected components comprising the Reference 75 SE combine to provide an amplifier which transcends traditional hi-fi, instead relaying music with realism and tangibility.

Visually, the Reference 75 SE hearkens back to past Audio Research products, taking inspiration from earlier amplifer designs. With its two large VU meters, which display power output as well as provide bias adjustments, the Reference 75 SE has a timeless appearance resembling precision laboratory equipment and an overbuilt, industrious aesthetic. Offered in both natural aluminum and black finishes, the understated look will complement any system.

The KT150 vacuum tube delivers power from the amplifier to your speakers. Newly designed solely for the audio industry, the KT150 offers higher power handling and current delivery. A matched pair of tubes per channel run conservatively, ensuring stable operation and many hours of trouble-free listening. Custom designed capacitors couple the output of the tubes to the speakers for the purest signal possible.

The Reference 75 SE is the new generation from a lineage of amplifiers only Audio Research could produce. Experience real music and unleash the capacity of your system – music in High Definition®.

Audio Research Reference 75 SE Stereo Tube Amplifier - Manual

Electronic Specifications

POWER OUTPUT
75 watts per channel continuous from20Hz to 20kHz. 1kHz total harmonic distortion typically 0.6% at 75 watts, below 0.05% at 1 watt. Approximate actual power available at ‘clipping’ 76 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) 7Hz to 60kHz.

FREQUENCY RESPONSE
(-3dB points at 1 watt) 0.7Hz to 75 kHz.

INPUT SENSITIVITY
1.4V RMS BAL for rated output. (25 dB Bal gain into 8 ohms.)

INPUT IMPEDANCE
300K ohms Balanced.

OUTPUT POLARITY
Non-inverting. Balanced input pin 2+ (IEC-268).

OUTPUT TAPS
8 ohms, 4 ohms.

OUTPUT REGULATION
Approximately 1.0dB 8 ohm load to open circuit (Damping factor approximately 8).

OVERALL NEGATIVE FEEDBACK
15dB.

SLEW RATE
10 volts/microsecond.

RISE TIME
4.0 microseconds.

HUM & NOISE
Less than 0.06mV RMS – 112dB below rated output (IHF weighted, input shorted).

POWER SUPPLY ENERGY STORAGE
Approximately 520 joules.

POWER REQUIREMENTS
105-125VAC 60Hz (210-250VAC 50Hz) 410 watts at rated output, 500 watts maximum, 230 watts idle.

TUBES REQUIRED
2 – Matched pair KT150 – Power Output; 2 – 6H30 Driver.

DIMENSIONS
19″ (48.3 cm) W x 8.75″ (22.2 cm) H x 19.5″ (49.5 cm) D. Handles extend 1.5″ (3.8 cm) forward.

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

The SkyFi Testing Process for Tube Amplifiers:

We start with a visual inspection of all internal components to make sure there are no signs of stress or aging. Capacitors are checked for telltale sings of bulging or leaking, resistors are checked for signs of overheating or cracking, and tubes are inspected for signs of stress overheating or cracking.

We then power up the unit carefully and run a simple 1k sine wave while monitoring the output on an oscilloscope for signs of distortion or noise. Finally we run the amplifier to its full rated power into the appropriate resistive load provided by our Sencore amplifier tester. If there is an issue, it will usually be noticeable at this point. If it all looks clean we will often test for THD (Total Harmonic Distortion) measured by our Keithley distortion meter, and compare it against the original manufacturers specifications. The amplifier the remains powered on to "burn in" on our test bench for a few hours to make sure there are no heat related issues. If there are balanced inputs available they will also be tested.

We also test all tubes for output gain and leakage on our calibrated B&K 747 tester against the original manufacturers specifications. If needed, the tubes will be replaced from our vast NOS (New Old Stock) vintage or modern inventory.

Final testing involves pushing actual music thorough the amplifier. We've learned over time that some issues are only noticeable to a trained ear while listening to familiar source material. Our test bench has reference vintage KEF speakers that we're very familiar with which quickly reveal any discrepancies. Some amplifiers will then move into our listening room where they are tested with our in-house reference speakers of choice.

Please click here for detailed specifics regarding our specialized packing process that separates us from the rest.