user manual
TFS-780
TFS-780 user manual
Page 47
Reset is automatic once the temperature has fallen to around 60°C. During this time the fan
continues running at full speed to reduce the temperature as quickly as possible. However
owing to the heatsink's very high thermal capacity, it is normal for the cooling-down (hence
reset) to take a few minutes.
If over-heating occurs, it is worthwhile checking:
♦
The load impedance. Are you driving a speaker with an impedance of less than 4 Ohms?
♦
The drive level. Is the amplifier regularly being driven into hard clip?
♦
The filter(s), see the above section.
♦
The rack airflow.
♦
System stability. Check grounding and shielding. Check for RF and noise on the
incoming lines. Use an oscilloscope with a bandwidth of 100MHz.
If just one channel is in use, and temperatures are running high, switching on the unused
channel can help cooling, by augmenting the airflow.
Fan Speed Setting
The cooling system uses continuously variable speed fans, the speed of which is dependent
on heatsink temperature. The fan idles at switch-on, and if the heatsink's temperature rises
enough (and this may take some time), it will speed up to provide the required extra cooling.
Fault Modes
The TMC-750 and TMC-1250 have been designed to respond intelligently to fault conditions
which can arise within the amplifier from four main areas: Thermal, Voltage, Current, Output.
Thermal
Thermal Thermal
Thermal Excess temperature causes the amplifier channel to mute. The TEMP LED lights. Re-
cycling is automatic, once the temperature has fallen to below 60
°
C.
Voltage and Current
Voltage and CurrentVoltage and Current
Voltage and Current Certain life-threatening faults cause the amplifier power supply to
immediately latch off ('Latched Kill'). The TEMP LED then flashes. Should this occur, check
for the following:
♦
Mains voltage outside limits.
♦
Internal amplifier fault or failure.
To Next Page
Loading...
Need help?
General