Park Audio II DF series, Руководство пользователя

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DESIGN FEATURES
Physical Design
The amplifier is enclosed in a metal (steel) case of 88 mm (2U) height. The
amplifier is designed to be standard rack-mounted (RACK 19").
Power Supply Unit
All four channel of the amplifier share the same pulse power supply unit.
Cooling System
The amplifier features a forced cooling system which is common for all four
channels. The amplifier and the power supply unit are cooled with a single fan blowing
front to rear. The cooling system provides for a double-step intensity-cooling rate
switching. At a normal temperature, the fan runs at a low speed, thus generating the
least noise possible. When the amplifier is set to deliver a high output power or when
the ambient temperature is higher than normal, the cooling system may switch the fan
to the other (higher) cooling rate.
Output Stage
The output stage of this power amplifier is designed according to Class D
technology to deliver high efficiency and least heat. The high switching rate ensures the
high sound quality comparable with the best analogue amplifiers.
Balanced Inputs
The use of balanced inputs provides for an essential reduction of the environment-
induced hum and noise interference with long input connecting cables.
Line Outputs
The amplifier line outputs are parallel to the inputs (each along the respective
channel) and provide for parallel connection of several amplifiers with standard signal
cables using XLR connectors.
Mode switch
3-position slide switch for each pair of channels.
Operating modes available:
– STEREO – two channels drive two separate loads from two separate signal sources;
– MONO – two channels drive two separate loads from a single input signal source;
– BRIDGE – two channels drive a common load from a single signal source.
Mode switches are located on the rear panel.
Input Filter
To improve the performance of loudspeakers, the amplifier incorporates a switch-
selectable high-pass 4-th order filter with 24dB per octave slope rate. This is the filter
recommended by all major loudspeakers manufacturers. This filter cuts off any signals
below 45Hz, which generally cannot be reproduced by most of the professional
loudspeakers.
The filter significantly reduces the travel of the LF speaker cone below the
loudspeaker frequency cut-off point (which is especially good for phase-inversion
loudspeakers) thus making it possible to increase the power applied to the LF speaker
without any danger of its overheating. The power of the amplifier is not wasted for cone
flapping and allows the loudspeaker to achieve higher sound pressure.