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Acoustic Research Amplifier

Integrated Amplifier (1971)

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Acoustic Research Amplifier


The amplifier circuitry used in the Acoustic Research amplifier receiver will provide any speaker system with an accurate and powerful signal.


Power output: 50 watts per channel into 8Ω (stereo)

Frequency response: 20Hz to 20kHz

Total harmonic distortion: 0.25%

Damping factor: 40

Input sensitivity: 2mV (MM), 200mV (line)

Signal to noise ratio: 57dB (MM), 75dB (line)


service manual   English -

instruction/owners manual   English - Daniel Shorr

spec sheet   English - rsigurdson

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Reviewed Mar 20th, 2016 by tutor turtle

Have this on my bench for cleaning and check out. It sounds very nice consisting it's age (almost 50), but it does have that vintage sound, a little soft & tubey, slightly colored midrange. There are four large electrolytic caps that are bulging and should be replaced, I'm sure this is the source of the 'vintage' sound.

Has anyone found a good source for replacement caps? I'll need to get a solid parts estimate before I can economically justify offering the service to the customer.

Reviewed Oct 11th, 2014 by Thol

I am rating this amp as a nine for this reason: regardless of any source I had at the time, it never failed to deliver an exciting, unbridled sound that really surprised owners — friends and fellow audio-fans — who owned much more expensive and more modern equipment.

About 12 years ago, before shipping it to Japan where I was working, a friend who had a then recent edition of the NAD amp agreed to to have a shoot-out.The unit had been idle for so long I was reluctant to power it up, let alone let it fly. Nevertheless, we ran these little beasts to the tits. In the end we agreed it was a draw. One amp had this and the other had that. And even then, it was close.

CODA: not bad for an amp that had not been powered up for a decade ... and had performed for thousands of hours with no service or even a dusting.

This music machine was not dummied down for the zombie masses of consumers. It proceeded that era. Like the NAD, it's a balls out, no-prisoners-taken instrument for nasty hard rock, but at the same time, the AR will move your heart to your mouth when rendering a baroque opera. I am not sure about the NAD, but that was years ago.

I still have this amp and plan on restoring it to its true place in audio glory.

That's why it is a NINE. Ten? Well ... it earns points for shear guts and superior engineering. I've listened to systems costing vast fortunes more, but his little machine has delivered more passion than most of the boutique systems costing a galactic amount of money more than I paid for this classic instrument. There was a time when as a poor student I had the AR, a Dynaco FM-3 and the CBC-FM as a source — all I needed, and always a to-the-bone, passionate experience.

Cheers — Thol



AR amp

thank you!

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