Audio Research - Classic 60 Tube amplifier

Audio Research Classic 60 amplifier


The Audio Research Classic 60 is a hybrid power amplifier (valves and transistors) with FET circuits. A true giant in sound, very musical, delicate, subtle, clear, with addictive transparent sound detail and surprisingly effective channel separation!

This device has just undergone a review and cleaning, with all valves replaced (which have not yet reached 30 hours of operation). I would say it is 'like new' despite its age.

Power specifications do not always describe the actual capabilities of an amplifier. Qualities such as dynamic stability, clarity, and subtlety are much more important.

In terms of listening language, this means an impressive bandwidth, a virtually imperceptible noise level, and musically satisfying sound pressure levels (SPL) at significantly lower gain settings. Dynamics, individual instrument timbres, soundstage, and musical emotion emerge from a velvet black silence. This amplifier opens a window of transparency in a way that offers us a deep and wide soundstage, providing great pleasure and long hours of listening without any auditory fatigue.

In summary, the Classic 60 reveals a much more comprehensive musical program than amplifiers with a nominal power two, three, or four times higher than its seemingly modest 60 W per channel (at 16 ohms). But the Classic 60 is more than capable of powering virtually any sound column, even in spacious listening rooms.

Practicality is also among the main attributes of the Classic 60. For example, the DC balance of the output valves is maintained automatically, while the valve bias continuously adjusts to input voltage variations. Performance remains impeccable without uncomfortable adjustments or corrections. The quiet fan cooling, combined with triode operation, means a significantly longer valve lifespan. An owner of a Classic 60 can expect years of low-maintenance performance.

Technical specifications

Output power: 60 watts per channel at 16Ω (stereo)
Response frequency: 15Hz to 20kHz
Total harmonic distortion: 1%
Damping factor: 30
Input sensitivity: 0.55V
Signal-to-noise ratio: 84dB
Speaker load impedance: 4Ω to 16Ω
Valve complement: 8 x 6550, 4 x 6FQ7/6CG7
Dimensions (width, height, depth): 480 x 180 x 400 mm
Weight: 28.6kg
Release year: 1988

The Audio Research Classic 60 features a classic style, with the power and output transformers at the front of the chassis, behind a brushed aluminum panel, and the tubes, filter capacitors, and circuit board behind the transformers, under a black wire cage. Two silent fans at the back of this cage direct cooling air over the two groups of four 6550 output tubes. The inputs are made through gold-plated RCA connectors, while the outputs are obtained from two terminal strips, one per channel, equipped with non-magnetic brass screws.

The only control is an on/off switch on the front panel, accompanied by two green LEDs and two fuses, one for power supply and the other for the high voltage regulator of the input stages and driver.

The high-standard construction and the quality of the parts are very high.

An interesting detail is that Audio Research states that replacement valves do not necessarily need to be paired, although paired valves offer better performance.


Given the weight of the amplifier, I prefer to coordinate delivery with the buyer; I am available to help find an economical and secure transportation option.


NOTE: column cables not included. I can sell them at an additional cost.