Operation Manual
5. Operation and performance
24
C SERIES Operation Manual rev 2.0.0
The VHF protection is indicated by a yellow LED on the amplier front panel, with output muting for six seconds
when active. It is reported as a fault via the NomadLink network on the DeviceControl GUI.
5.6.3. DC protection
DC protection is implemented on each output to prevent damage to connected loudspeakers. DC present at the
output will trigger muting and illuminate the fault LED indicator. Any DC present at the output indicates a hardware
malfunction that requires servicing of the amplier.
5.6.4. High-impedance warning (open load)
A high-impedance (open load) condition is indicated when an input signal above approximately -29 dB is detected
and no functioning loudspeakers are connected to the amplier. The fault in indicated by a red Sig/Hi-imp LED.
The indicator is green when a valid load is present under the same input signal conditions.
NOTE: Since the high-impedance detection initially triggers only when the input signal rises above
-29 dB, it might cause the indicator to rst turn green, and then orange, even in situations where no
speaker is connected.
5.6.5. Low-impedance protectioin (short circuit)
A low-impedance or short circuit fault is detected when current draw is high (Current Peak Limiter active) and
when, simultaneously, output signal is low. When this occurs, the amplier protects the output stage from damage
by muting the output signal and bypassing the circuits. Indication of this fault is a constant orange illumination of
the Current Peak Limiter (CPL) LED on the front panel. The protection will sequence at six second intervals to
re-measure conditions. If the low-impedance fault is no longer detected, the amplier will un-mute.
20 Hz 10 kHz 20 kHz
30 kHz
- 6 dB slope
VHF protection
operation area
Max. Peak
output power
Max. Continous
output power
Output
power
Attack time
VHF protection
Slow
Fast
20 Hz 10 kHz 20 kHz
30 kHz
Figure 5.6.2: VHF protection operational area