22
aC POWER SWITCH
This button triggers the relay that provides power to the amplifier. This unique power switch will glow blue dimly. When turned on, it
illuminates brightly.
INDICaTORS
The IPR2
™
amplifiers feature five front-panel LED indicators per channel: ACTIVE, SIGNAL, DDT
™
, TEMP and DC. These LED indicators inform
the user of each channel’s operating status and warn of possible abnormal conditions.
aCTIVE LED
The Active LED indicates that its channel’s output is closed and the channel is operational. It lights under normal operation and remains on,
even when the channel is in DDT gain reduction. These protection features leave the output relay closed. If the Active LED goes off, there is no
signal at the output connectors.
SIGNaL LED
This LED lights when its channel produces an output signal of about 4 volts RMS or more (0.1 volt or more at the input, with 0 dB attenuation
and standard x40 voltage gain). This signal indicates whether a signal is reaching and being amplified by the amplifier.
DDT
™
(DISTORTION DETECTION TECHNIQUE) LED
A channel’s DDT
™
LED will light at the onset of clipping. If the LEDs are flashing quickly and intermittently, the channel is just at the clip
threshold. A steady, bright glow means the amp is clip limiting, or reducing gain to prevent severely clipped waveforms from reaching the
loudspeakers. See the Distortion Detection Technique section for more information. During initial power-up the DDT LED will light to indicate
that the gain reduction circuitry is activated. This prevents sudden signal bursts when the speaker relays are closed.
TEMP LED
In the unlikely event of an unstable thermal condition, amplifier protection will be activated and will shut down the offending channel. The
Temp LED will remain illuminated until safe operating temperatures have returned.
DC LED
In the event of abnormal operating conditions, the IPR has built-in amplifier protection. Under conditions that would normally damage the
power amplifier, the DC LED will illuminate and the amp will automatically attempt to restart to correct the condition. If the amplifier does not
return to normal operating status, contact your local authorized service center.
INPuT ATTENuATORS
Whenever possible, set the attenuators fully clockwise to maintain optimum system headroom. The input attenuator controls, located at the
front panel (one for channel A, one for channel B), adjust gain for their respective amplifier channels in all modes. See the specifications at the
end of this manual for standard voltage gain and input sensitivity information.
Front Panel
1
8
8
7
6
5
4
2
3
3
1
8
8
7
6
5
4
2
3
3
1
2
3
4
5
6
7
8
IPR2
™
7500
IPR2
™
5000
