The power amplifier section of the Pioneer A-8 adopts a non-switching amplifier system which combines the merits of the class A amplifier's high quality and the class B amplifier's high efficiency for a continuous power output of 90 watts per channel, min at 8 ohms from 20 Hz to 20,000 Hz with no more than 0.005% total harmonic distortion.
The voltage amplification stage features two current detector circuits to control the bias circuit voltage and prevent the current flowing to the power transistors from being cut off.
As a result of these innovations, the distortion generated when the transistors are switched is suppressed, the dynamic distortion is improved and the sound takes on an extra dimension in clarity extended to the high-frequency range.
The power amplifier features a DC servo circuit employing an operational amplifier.