Yamaha EM1620 - Manual (Page 14)

LIMITER OPERATIOIM
The LIMITER protection circuitry is activated when the
maximum power rating of the SP OUT signal (i.e., 200W
into 4 ohm loads) is exceeded. The LIMITER is effec­
tive to 15 dB overrange. When the signal is less than 15
dB overrange, the LIMITER activates and the output,
signal is sent to SP OUT with minimal distortion. How­
ever, when the power of the input signal is greater than
15 dB overrange, the LIMITER is no longer as effective
and the signal delivered to SP OUT will become dis­
torted.
INPUT - OUTPUT (LIMITER) RESPONSE
INPUT - THD (LIMITER) RESPONSE
INPUT(-20 dB, Rs=600n) — SP OUT(4 Q)
GEQ: flat
CH VOLUMÈ and MASTER volume: Max
Frequency: 1 kHz
0.1
0.05
-30 -20 -10 0
INPUT LEVEL (dB)
TROUBLESHOOTIIMG
The following table lists the main causes of abnormal operation and the corrective measures required, as well as the
protective circuit operation in each case.
Indicator display Probable cause Remedy
Sound is distorted
Input signal strength is too high.
Limiter overrange protection
(+15dB) has been exceeded.
Turn the channel VOLUME control counter­
clockwise to decrease the input signal level or
decrease the output level cormected to the
INPUT jacks.
The amplifier load is excessive. Use a speaker system with the correct load im­
pedance. (Refer to page 8 for details.)
PROTECTION indicator is lit
and no sound comes from the
speakers.
The heat sink temperature has
exceeded 100°C.
Check the amplifier ventilation conditions and
take appropriate measures to improve airflow
around the amplifier.
A DC voltage of +/-2V or greater
was generated in the power ampli­
fier’s output cireuit. Consult your dealer or nearest Yamaha service
center.
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