ACCUPHASE A-65

The A-65 is built with no compromise and with fanatical attention to detail Accuphase is famous for. It is a pure class A amplifier with power MOS-FET devices in parallel push-pull configuration. Should you need a bit more technical information please refer to product sheets that are available at Accuphase’ s website and that share unusual amount of information including the block schemes and photos of the PCBs.
I may perhaps point out that the A-65 does not have a separate power supply for each channel and there is only one 1kVA toroidal transformer to be found inside. However, the toroid is air-tight sealed in a non-resonant aluminum housing filled with damping material with pre-defined heat transfer characteristics. Remove the lid and you’ll be surprised by two oversized filtering devices with the capacity of 82,000pF. Signal paths are kept completely balanced as is the rest of electronics inside that are mounted directly onto massive heat-sinks and Accuphase employs current rather than voltage feedback to reduce phase shift. The inner layout is very neat and tidy, the finest I have ever seen.

What is significantly different in the A-65 vs the A-60 is its input stage which is designed as an instrumentation amplifier (a kind of differential amplifier that is used in measurement and test equipment). By using this type of input stage Accuphase would like to achieve great accuracy, better stability, less input impedance sensitivity and lower distortion values.

The A-65 is declared as a 2x60W amplifier into 8 ohms, however, this is a very conservative rating; the maximum power output is usually on very safe side in Accuphase’s manuals but if you read them carefully or measure the actual output on a test bench you would soon reveal that the A-65 is almost perfectly linear from 1 to 16 ohms, which consecutively means that it can deliver astonishing 2x118W into 8 ohms or 2x202W into 4 ohms. Provided your listening room is not the size of a hangar and your speakers are normally sensitive the power reserve should be ample. The easiest thing to do to check the real power requirements in your listening environment is to turn on the digital read-out on the A-65’s display.

I really like Accuphase’s famous speaker posts with oversized plastic nuts and plenty of room around. The grip is extreme so be careful not to squash your wires. It is possible to use banana plugs and it makes the Accuphase’s post even better than the winged nuts of Mark Levinson which are the runner-ups. From the rear there are balanced (XLR) and single-ended (RCA) inputs, IEC outlet and toggle switch for switching the amp into a DUAL MONO (bi-amping) mode or into a bridged mode. In the bridged configuration the A-65´s output rises to 480W into 4 ohms.

The fascia is occupied by large display (a bit wider and lower than with the A-65) with all the indicators: the red digit read-outs, bar display, input mode and configuration mode LEDs. Unlike the A-60 the new Accuphase hides its control buttons under a cover, including a gain selector with four settings: 0, -3, -6 and -12db; if your speakers are sensitive enough then a lower setting is going to further minimize residual noise.