AudioNemesis PA-1m Manual del usuario - Página 6

Navegue en línea o descargue pdf Manual del usuario para Amplificador AudioNemesis PA-1m. AudioNemesis PA-1m 12 páginas. Class a mono power amplifier

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The power supply makes use of a high quality and low noise toroidal transformer with many separated

secondary windings, dedicated to each requirement of the circuit. Requested voltage for the output stage

has very special, very fast and soft-recovery diodes, with low ESR electrolytic capacitors. The ripple is very

low assuring very low noise. High value capacitors assure energy while low value and very fast ones

(positioned close to the power transistors) assure speed. The voltage is unregulated. Regulated power

supply sounds better than un-regulated one only if regulation is necessary for a stable work of the audio

stage. Otherwise, it's very difficult to reach better results. Our driver stage is very stable with stable sound

performances and this allows the use of a very good but un-regulated power supply too. Filament (heater)

power supply is regulated and precisely stabilized at the optimum voltage for assuring long life of the

triode. Furthermore, stabilized dual voltages are dedicated to other non-audio circuits. A custom designed

mains filter completes the power supply.

The complete circuit is divided in three different PCBs: audio signal, output stage power supply, high

voltage and filament power supply. This does optimize space and performance. The signal path is as short

as possible.

As usual, all components are of the best quality, with Sanken ring-emitter power transistors, Toshiba audio

driver transistors, very high quality passive parts and a NOS 5687WB double triode with a ceramic socket.

The pure aluminium heat sink let the circuit manage the high temperature of the output transistors caused

by the high idle current for a correct Class A bias. The Bias circuit, moreover, sets a very stable output idle

current since the turn on of the amplifier. The fast correction this circuit is capable of allows a warm-up of

about 30 minutes, even if we suggest a longer period for the best performance.

The chassis is very similar to the one used in other AudioNemesis products, adapted to the high temperature

typical of Class A amplifiers.

M_PA1m REV.01 ENG OCT 2009