Accuphase A-48 – Stereo Power Amplifier

Description

Tecnifi announces the availability of the power-packed Accuphase A-48 Stereo Power Amplifier. Feature-packed with a six-fold parallel push-pull architecture with power MOS-FETs, as well as ideal gain allocation realized with discrete semiconductors in an instrumentation amplifier configuration, the A-48 harnesses a wealth of advanced technology. Its remarkable performance is exemplified by a signal/noise ratio of 117 dB, output of 360 watts into 1 ohm (music signals), and a damping factor of 800. The newly designed output protection circuit can detect any short-circuiting of the speaker terminals, for absolute peace of mind. This power amplifier is the most stellar instrument for immersive music appreciation on the highest level.

Instrumentation amplifier topology for improved noise performance
The Accuphase A-48 employs an instrumentation amplifier configuration that is highly effective in keeping external noise from affecting the signal transmission lines. Furthermore, the input stage is designed for high gain (22 dB) and the power amplification stage for low gain (6 dB). Consequently, the signal emerging from the signal input section has a large amplitude which makes it much less prone to external interference, thereby further improving the noise performance.

Signal input section with high gain
Similar to the higher-ranked A-75, the signal input stage of the A-48 is entirely configured with low-noise discrete circuit components. This makes it possible to design the circuit for a high gain of 22 dB (a multiplication factor of approx. 12.5), something that cannot be achieved with OP amp ICs. As a result, the S/N ratio of the amplifier is an astonishing 117 dB.

Linear output characteristics over entire load impedance range
The power amplification stage employs a 6-parallel push-pull arrangement of power MOS-FETs mounted directly to large heat sinks for highly efficient thermal dissipation. The result is fully linear power progression of 45 watts into 8 ohms, 90 watts into 4 ohms, 180 watts into 2 ohms, and 360 watts into 1 ohm (music signals). Plus, the impressive damping factor of 800 means that the amplifier can easily and competently drive any kind of loudspeaker.