Marantz MA-9S1 Reference Series Sheet - Page 7

Monaural Power Amplifier MA-9S1 Instantaneous current delivery capability Fully balanced monaural power amp To minimize the influence of strong "return current" occurring from the loudspeaker system, the circuit for the power amp consists of two amplifiers giving a voltage gain amp of 23dB, in a 3 paralleled push-pull balanced construction, for the final buffer amp of 6dB. Choke input system The power supply of the voltage gain amplifier's adopted choke input system has few ripples and is durable with load changes. This can prevent noise from the amplifier as well as reduce noise from the primary winding, resulting in a clean power supply. Ultra low impedance amplifier The buffer amplifier's power supply block, which supports the high current delivery capability, uses a capacitance input system to realize very low impedance. The Super Ring power transformer, the low impedance electrolytic capacitors, the very large gauge internal wiring, and the thick pattern PCB all contribute in supplying the required power. Even if amplifiers have the same power specifications, their performance may not be the same due to a difference in current delivery capability. The delivery capability of a power amplifier depends on how instantaneous the current supply is. That's why the power supply for the MA-9S1 was completely revamped to give it a truly instantaneous current supply capability that has been increased three times as much compared to any Marantz product designed before.