Serie H /
H series
Manual del usuario /
User's manual
11
INTRODUCTION
General
Thank you for purchasing a D.A.S. power amplifier. It has been
built with the most advanced modular technology, and has
been designed through the use of computer-aided design for
both the electronic and mechanical parts.
Features
•
Class H
•
Dual balanced XLR inputs
•
Binding post and Speakon output connections
•
Variable speed back-to-front fan cooling
•
Front located volume controls
•
Overload, short-circuit, DC and thermal protection
•
Each channel has separate circuitry, built onto a separate
power module, facilitating servicing in the event of a
breakdown
•
Stereo, parallel and mono operation modes
•
Clip limiters
•
Clip, protection and idle LED indicators
FRONT PANEL DESCRIPTION
A) POWER SWITCH
Turns the amplifier on (“|” position) and off (“0” position).
There is a turn-on delay, to ensure that all appropriate voltages
are properly adjusted. The switch is of an automatic thermal-
magnetic type and switches off when the power supply
protection disables the mains supply.
B)
POWER LED
When lit, this LED shows that the amplifier is on.
C) INPUT
LEVEL CONTROLS
Volume levels for each channel can be adjusted by using the
knobs found on the front panel. The effect is the same as
adjusting the gain of the amplifier. Gain is maximum when the
LEVEL rotary potentiometer is rotated fully clockwise.
D)
CLIP LED
In the event that the signal’s excursion exceeds the maximum
voltage from the power supply, the unit will indicate saturation
through the clip LED of the channel involved.
E)
PROTECTION LED
When a channel’s output is disconnected by the amplifier’s
protection, this LED is on.
A channel’s protection may be triggered by:
•
Overheating sensed at any part of a channel. When the
amplifier has cooled down, the channel’s output will be
connected and operation will resume. The control circuit
has some degree of built-in hysterisis to avoid turn-on
and off oscillations.
•
Presence of DC at a channel’s output. Since it may
severely damage speakers, the amplifier will deactivate
the output in the event that DC levels are too high. If load
impedance is too low, the amplifier is also deactivated.
Once DC is no longer present, the
PROTECTION LED will
turn off and output is reactivated.
•
Short-circuit at a channel’s output. Although this
protection is provided, it is dangerous that the amplifier
remains in this situation for a long time. In case of a
short-circuit, turn off the amplifier while examining any
equipment connected to the amplifier’s output, together
with the connections and cabling. In this case, once the
short circuit is gone the output is NOT reactivated, but
the amplifier needs to be switched off and on.
•
When the amplifier is switched on, the output is also
deactivated for a few seconds to prevent dangerous
transients from damaging the speakers, and the
PROTECTION LED is on until the amplifier is ready for use.
F)
SIGNAL LED
This LED shows the presence of signal at the amplifier’s inputs
and is dependent on the position of the
LEVEL control.
G) COOLING AIR OUTLET GRILLES
Fan cooling permits airflow through the most vital parts of the
amplifier. Since the airflow finds its way out through these
grilles, keep them as clean and dust-free as possible to assure
proper cooling.
