Output Voltage Peak Limiter (Vpl); Output Current Peak Limiter (Cpl) - Lab.gruppen FP14000 Operation Manual

7 OPERATION AND PERFORMANCE

7.4.7 Output Voltage Peak Limiter (VPL)

Voltage Peak Limiter (VPL) is a unique feature in
FP+ Series amplifiers. It is used to select the maxi-
mum power available on each output channel. VPL
levels are set using the rear-panel DIP-switches; eight
level positions are offered on all models except the
FP 6000Q, which offers six).
fP 14000
V rms
V peak
195 138
170 121
140 99
116 82
100 71
80 57
66 47
54 38
fP 9000
V rms
V peak
170 121
140 99
116 82
100 71
80 57
66 47
54 38
fP 4000
V rms
V peak
121 86
101 72
83 59
70 50
56 40
47 33
38 27
Table 7.4.7: V peak to Vrms tables for the
FP+ Series
20 FP+ Series Operation Manual
fP 13000
V rms
V peak
195 138
170 121
140 99
116 82
100 71
80 57
66 47
54 38
fP 7000
V rms
V peak
155 110
121 86
101 72
83 59
70 50
56 40
47 33
38 27
fP 10000q
V rms
V peak
150 106
121 86
101 72
83 59
70 50
56 40
47 33
38 27
fP 6000q
V rms
V peak
101 72
83 59
70 50
56 40
47 33
38 27
The values for VPL are displayed as maximum Voltage
Peak. To translate Voltage Peak into Vrms, you must
divide the Voltage Peak values by 1.41 (see table).
The VPL allows you to set the correct maximum
output peak power for optimum performance with
the connected speakers. The correct setting depends
on the system type and the specific load connected
to the channel. Since each channel can be configured
to deliver either very high voltage peak power OR
high current draw at low-impedances, it is important
to set the VPL correctly.
If you choose a lower VPL setting, you only reduce
the maximum output voltage. At the same time, this
allows more current headroom for low-impedance
loads. The amplifier thus runs at higher efficiency,
with a significantly reduced risk of going into thermal
protection.
7.4.8

Output Current Peak Limiter (CPL)

The Current Peak Limiter (CPL) ensures that the
amplifier will not be damaged by forcing the amplifier
to deliver current levels to the outputs that exceed the
physical limits of the transistors. The CPL keeps the
amplifier within the Safe Operating Area (SOA).
The CPL is non-adjustable and has different limit
values depending on model type.
CPL activity is indicated by illumination of an orange
LED for each channel on the front panel. Warnings
also are shown in the DeviceControl software's
GUI.
A steadily illuminated orange CPL LED (with MUTE
illuminated) indicates a short circuit situation (or very
low-impedance). The output will mute for 6 seconds
before measuring the output impedance again. This
will continue until the short circuit is fixed, at which
time the output will automatically un-mute. An input
signal must be present to allow detection of short
circuit or low-impedance conditions.
The problem can be solved by checking
input and output cables and examining the
state of the loudspeaker load. If there is no
short circuit present, then the condition may
be rectified by lowering the VPL or input levels.