Boulder 3050 - Input DC Offset Voltage Detection; Clip Detection; Thermal Protection

Operation
2-3
Input DC Offset Voltage Detection
The Boulder 3050 Mono Power Amplier is a direct-coupled power
amplier with a servo for zeroing out any DC voltage offset coming from
the preamplier or other sources connected to the amplier’s input.
If this input DC is sufcient to cause three volts or more at the
output, a loudspeaker protection circuit will mute the amplier output
by electronically disconnecting itself from the loudspeaker. The power
indicator will turn red. This condition will continue until the DC is removed.
If the indicator remains red, it is recommended that the user correct
the DC offset of the source device before continuing.
Clip Detection
Clipping of the waveform results when any amplier is driven at too high a
level. A clip detection circuit is included in the 3050 Mono Power Amplier.
The indicator will indicate clipping by momentarily turning from
white to red. Both voltage and current modes of clipping will be detected,
although generally it is only voltage clipping which occurs.
Thermal Protection
A thermal protection circuit prevents high case temperatures which
are unpleasant to touch and potentially harmful to the amplier. The
thermal cutout circuit will mute the amplier when the transistor cases
reach 85°C, and the indicator will turn red.
If this happens, more ventilation should be provided for the amplier.
Maintenance
No routine maintenance is required for the Boulder 3050 Power
Amplier. However, to keep the operating temperatures at a minimum, do
not block the heat sink ns, and remove any dust buildup that may occur.
Operation