Operation (Hardware references)
8.3 Cooling fans
Two temperature and level controlled fans are incorporated for
cooling the internal components, which allows greater cooling
during louder program material. The fan speed is consequently
reduced during quieter passages preventing background noise
interference. If the unit heats up a «Temp. Warning» is issued and
the fans will give full cooling power permanently.
d&b 40D Reference manual 1.3 en34