Sirus ELXA2600, User Manual

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6.6. Bridged Mono Mode Connections
7. LX Clip Limitting
At the amplifier’s full power limit, or clipping point, LX will be activated. This is indicated by an
illumination of the Limiter LED. The channel gain is automatically reduced, protecting the
loudspeakers from potential damage from the high power, continuous square waves that would
otherwise be produced. LX may be activated by uncontrolled feedback, oscillations, improper
equipment gain settings, or an equipment malfunction upstream from the amplifier. Only steady or
excessive clipping (not normal program transients) will trigger LX. The circuit is virtually transparent in
operation and full signal bandwidth is maintained.
8. IGM Impedance Sensing
IGM (Instantaneous Gain Modulation) is an innovative circuit that allows the amplifier to operate safley
into difficult loads. When the amplifier sees a load that overstress the output stage, the IGM circuit
adjusts the channel gain to a safe level. Like LX, the IGM circuit is inaudible in normal use. In addition,
if extreme and sustained low impedance is encountered, the amplifier’s output relay will open.
9. Auto Ramp Protection
Auto Ramp operates every time the amplifier is turned on or is reactivated after a protect condition is
corrected. This exclusive feature gradually increases gain to the attenuator setting avoiding
unnecessary stress on the loudspeakers.
10. Thermal Protection
Abnormally high heat sink temperatures will engage the protect circuit for the overheating channel
only. (An output relay disconnects the loudspeakers until nominal temperature range is restored.)
During this time, the Protect LED will light and the LCD display will show Protection and Fault if the
power transformer gets too hot, its thermal sensing circuit will disconnect both channel outputs. During
this time, the Active LED will extinguish, the Protect and Limiter LEDs will stay lit and the cooling fan
will continue running at low speed. Normal operation resumes once the transformer cools to a safe
level.