This series of amplifiers are designed to work with a 100V line especially for sound systems installed in office blocks,
shopping centres, supermarkets, bars, public buildings etc.
The main advantage of a 100V system is the reduced thickness of the speaker cables compared to low voltage amplifiers.
This is because the higher output voltage allows a much lower current flow for the same power. Another advantage of the high
output voltage is the amplifier's ability to cope more easily with voltage-drop when using long speaker cables.
On all PVA series amplifiers, the output stage is powered by a low voltage allowing not only use with mains voltage,
but also 24VDC (or 18VDC). Voltage switching is automatic and completely silent. The output stage utilises a specially wound
transformer to allow full acoustic operation at high frequencies. A modified push-pull configuration is used for the output stage.
This has the advantage of working in a similar way to a bridge configuration allowing a decrease of the filtering volume by as much
as a half. In contrast to conventional push-pull configurations, our output stage is fully complementary, giving, amongst other
advantages, lower distortion, without losing the advantages of a push-pull configuration.
The output stage circuitry is protected with the same devices used in stage-amplifiers. This includes: thermal protection,
input and output transformer protection, short circuit and overload protection, return limiter and soft switching (soft start).
Thanks to these features, it can be used in far more demanding conditions and gives greater fire and safety protection.
The amplifiers are equipped with priority inputs, switched automatically as soon as additional signals are detected.
The PVA series also has test inputs for connection of an ultrasonic remote control to test the efficiency of connections.
Balanced inputs allow the use of long cables without the risk of humming or mains distortion.
Subsonic filters protect the speakers which are, in this kind of installation, relatively low quality.
This also protects the amplifier from saturation of the output transformer.
The forced-cooling fan constantly adjusts its speed according
to the temperature of the heat sink. The result of this is
that when the amplifier operates at low volume, the fan works
at minimum speed or stops altogether, minimising dust intrusion
and increasing the amplifier's life.