Fan Cooling
The fan speed varies automatically to maintain safe internal temperatures. Keep the front and rear vents clear to allow full air flow. Hot air exhausts out the front of the amplifier so it does not heat the interior of the rack. Make sure that plenty of cool air can enter the rack, especially if there are other units which exhaust hot air into it. See (Figure 35).
Safe Operating Levels
The amplifiers protective muting system guards against excessive internal temperatures. With normal ventilation and 4 to 8 ohm loads, the amplifier will handle any signal level including overdrive‑but make sure that the speakers can handle the full power! However, lower load impedances and higher signal levels produce more internal heating. Into 2 ohm loads, frequent or prolonged clipping (indicated by constant flashing of the red CLIP LED) may trigger protective muting. Bridge mono mode doubles the output impedance of the amp; 4 ohms is the minimum load impedance. Heavy clipping may cause muting. If this happens, refer to the Troubleshooting, section.
Warm air exits the amplifier and rack.
Cool air enters the amplifier and rack.
— Figure 35 —
Troubleshooting
Problem: No Sound
Indication: POWER indicator not lit
Check the AC plug. Also check the circuit breaker on the rear panel.
Confirm that the AC outlet works by plugging in another device. If too many amplifiers are used on one outlet, the building’s circuit breaker may trip and shut off power.
An overload in Bridged Mono mode may cause the amplifier to click off for several seconds. Check the load impedance (4Ω minimum), or reduce signal level.
An amplifier which keeps shutting off may have a serious internal fault. Turn it off, remove AC power, and have the amplifier serviced by a qualified technician.
Indication: SIGNAL LED responding to signal level
If the green SIGNAL indicators are lighting normally, the fault is somewhere between the amp and the speaker. Check the speaker wiring for breaks. Try another speaker and cable.
Indication: SIGNAL LED not lit
If the green POWER indicator LED is lit and the fan is running, yet the signal LEDs indicate no signal, check the input. Make sure the signal source is operating and try another input cable. Connect the source to another channel or amplifier to confirm its operation.
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