Introduction; Features; Precautions; About This Manual - SYSTEMS SR703 Manual Del Usuario

SR703 | SR707 CONTRACTOR AMPLIFIER

INTRODUCTION

Congratulations on your purchase of the Asystems
SR703 and SR707 professional contractor power
amplifiers. The SR series is a line of power amplifiers
specifically designed for contracting application. The
SR703 and SR707 have independent channels and
is able to drive 200V, 140V, 100V, 70V, 50V or 25V
constant voltage lines� Each channel has its own
power transformer (toroidal type) secondary to provide
maximum audio separation (minimum sound leakage)
between two channels, minimizing interaction that can
otherwise occur on amplifiers with a common power
supply�

FEATURES

√ Automatic dual-speed, high efficiency fan cooling
√ Rear panel detented gain controls for security and
resetability
√ Stereo, bridge or parallel operating modes
√ XLR and barrier strip inputs
√ XLR in and outs for multiple amplifier operation &
easy signal pass-through
√ Fully short-circuit, temperature and DC offset
protection
√ Barrier strip connection determines output mode -
25V, 70V, 100V and direct low-impedance outputs
available
√ Toroidal output transformers provide full electrical
isolation and meet worldwide safety agency approval
√ 45Hz subsonic filter prevents speaker transformer
saturation with minimal effect on program material
√ Power-up muting

PRECAUTIONS

1. When first powering up the amp, keep the amplifier
gain controls all the off, in order to block potentially
damaging or annoying sounds caused by defective
cables or hookups� When turning up the gain, do it
gradually, until normal operation is verified� These
precautions are necessary with all high-power
amplifiers, since they have enough power to blow
most speakers in abnormal situations�
2. Check local voltage levels before connecting the AC
plug� Under no circumstances should the grounding
pin of the power cable be defeated�
3. Speaker Output Shock Hazard! The SR703 and
SR707 amps are capable of producing hazardous
output voltages� To avoid electrical shock, make sure
the cover is in place over the output terminals, and
do not touch any exposed speaker wiring while the
amplifier is operating�
English

ABOUT THIS MANUAL

Please be reminded that a power amplifier is a high-
current, high-power device and should be treated with
care and respect� Please read this manual before
connecting and operating your unit, and file it in a safe
place for future reference�

FRONT PANEL

1. Power Switch
The power ON/OFF switch with an LED indicator�
2. Protect LED Indicators
The SR703 and SR707 feature several types of protection
to prevent damage to the circuitry during turn-on or fault
conditions� If the LEDs light up, this indicates that one
of the various protections is safeguarding the different
sections of the amplifier and in these cases, the power
output is normally switched off until normal operating
conditions are restored�
• Loudspeaker protection: the power-on protection relay
prevents damaging thumps to the speakers as the
power comes on� When the amp is switched on, the
protect LED will light for a few seconds, and then go out,
indicating that the relay has closed�
• Thermal protection on the heat sink: If the amp
overheats, thermal shutdown protects the circuitry until
the temperature is reduced to a safe level�
• Short circuit protection: The Protect LED Indicator
will also light up if the speaker terminals are short-
circuited, or the impedance of the load is too low� In
these circumstances, the Protect LED will stay on until
the fault conditions are rectified.
Some protection situations require the amplifier to be
switched off and then back on for normal operating
conditions to be restored�
3. Signal "Status" LED Indicator
Each channel of the SR703 and SR707 features a signal
LED to show that there is an audio signal at the input to the
channel� The threshold for the indicator is -26dB, which
should be enough to avoid noise triggering the LED�
4. Limit LED Indicator
The SR703 and SR707 have built-in limiters on each
channel to prevent clipping� Should the signal reach a level
high enough to cause clipping, the limiter momentarily
reduces the input signal level, just enough to prevent it�
The limit LED lights whenever this occurs�
4