General informations

Project innovation

The qualifying element of the new AS-204 Power Amplifier is based on an innovating circuital solution: the CVG (Current Voltage Gain) output stage.

The implementation of an output stage that gains in both voltage and current joint itself to the precision and power of MOS-FET's, delivering a very good satisfaction to the most evolved listener too. From the electrical and circuital point of view, the MOS-FET output stage is driven by a voltage gain driver section: this has its own feedback loop so it's possible to use low power transistors, that are sharp, speedy and noiseless.

The MOS-FET's conduction band, extended up to 12V, allows a wide dynamic of linear driving, optimizing the overall efficency.

Thanks to the increasing of the gain/bandwidth product, it is possible to use fully the speed performance typical of these devices.

The low feedback value, 10 dB, that is proper of CVG stage, causes the system to be insensitive in critical point of load impedance, getting better in sound definition and peak power precision.

In brief:

THE PARTICULAR CVG TOPOLOGY

THE HIGH QUALITY COMPONENTS USED

THE OVERDIMENSIONING OF THE OUTPUT STAGE

THE LOW FEEDBACK VALUE

offer:

A NEUTRAL AND PRECISE SOUND, even from high dynamic sources, in combination with all speakers available today

A VERY INTERESTING COMMERCIAL PRICE

A SIGNIFICANT QUALITY/PRICE RATIO

Technological solution

The power stage employs the best available components for this application. In particular are used: fiber glass printed circuit board, with minimum path conductive tracks to control stray capacitance, selected and thermally coupled semiconductors, relays with parallel 5 MICRONS GOLD plated contacts, gilded connectors, high quality and low tolerance passive components. The main power switch is a very low resistance one, with gold plated silver contacts.

The supply unit utilizes a toroidal transformer which is inglobated with epoxydic resin inside a metal box (to reduce the disperse flux and mechanical shocks), and "Computer Grade" electrolithics capacitors for a 0,02 Farads total capacitance.

As for the MOS-FET power stage, the AS-204 P.A. outdoes similar devices on worldwide HI-FI scene, utilizing four semiconductors for each channel (2 per Rail): this allows to supply 15 A of output peak current, with total insensitiveness to a +/-90° load phase rotation. A power source like this needs an adequate heat sink: according to this, the external sides of the amplifier are made with large radiant surface extruded profile.

This characteristic helps in the best of ways the getting rid of the heat done by the output devices during the continuous and peak conditions, extending MOS-FET's life-time and achieving a continuous and reliable operation.

The minimum cable path and the advanced modularity of the inside parts allows an elevate performance repeatibility and a reduction of production costs.

Each single amplifier is subjected to instrumental and functional tests, done after an 8 hours load-test at least, executed at 1/3 of nominal power on complex load.