Listen SC Amp, User Manual

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Introduction
SC Amp
TM
Manual
11
Introduction
SC Amp is the world's only dedicated audio test amplifier. Specifically designed for the audio test market, it
incorporates several patented features unique to the needs of audio test and measurement. Unnecessary
features found in regular audio amplifiers have been eliminated to keep production line operation simple
and error-proof.
Features
z
SC Amp is a rugged and easy to use amplifier specifically designed for audio test
z
It is a mono amplifier with low distortion (THD <0.025%) and a low noise floor (>100 dB)
z
Fixed gain reduces calibration errors as there is no gain knob to be accidentally knocked or
tweaked when it is in use
z
A separate DC input is provided for the application of DC voltage offsets to the AC signal for testing
transducers under adverse conditions
z
Proprietary patented servo circuitry rapidly responds to DC offset step functions without ringing
(rise and fall times of less than 100 ms typical) allowing audio sweeps to rapidly follow offset
changes
z
Overload, temperature, and output protection systems prevent damage due to shorting, overload,
and high temperature conditions
z
SC Amp integrates seamlessly with Listen's SoundCheck
®
audio test and measurement software
and will also work well with other brands of test system
z
Four, rugged, 2-unit high SC Amps can be mounted in a single 19" rack opening
z
A proprietary, patented, active current monitor output permits impedance measurements that
maintain a high damping factor, unlike impedance boxes
z
SC Amp can accept balanced or single ended audio inputs from the audio interface
Front Panel
The front panel contains only an on/off switch and LEDs to indicate
power on, level, and DC offset. This simple front panel keeps
operation easy and error-proof as there is no possibility of
accidentally changing knobs or buttons.
- Power Switch with temperature indicator
Green : Power on, temperature OK
Red : Power on, internal temperature limit exceeded See
Over Temperature Standby on page 13
Level - Indicates the amplifier signal level:
Off : No input signal or level is below -30 dBV
Green : Input level is about -30 dBV. Also illuminates when a DC offset has been applied.
Yellow : Output level is about 3 dB away from clipping
Red : Output is very close to clipping or is already clipped
DC Enabled - Blue indicates that DC Input is on, the indicator is off when DC input is disabled
Figure 6-1: Front Panel