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PLM Series Operation Manual
7 OPERATION AND PERFORMANCE
7.1 Introduction to Operation
This chapter provides comprehensive information
on PLM Series connection, setup, operation and
performance. The detailed information included here
is essential to realizing the full functionality of the
PLM Series.
7.1.1 Operation precautions
Make sure that the Standby button on the PLM’s
front panel is either unlit, or is showing red (i.e., the
PLM is in STANDBY mode), before making any input
or output connections.
Make sure that the AC voltage is correct and
matches that printed on the label adjacent to
the AC mains connector.
Make sure that no signal is present at the input to the
PLM when powering it up to prevent any inadvertent
bursts of high level audio.
7.2 Power Output Performance
The PLM uses Lab.gruppen’s patented Class TD
technology in the output stages, which couples the
efficiency of Class D topologies to the sonic purity
of Class B designs.
The primary benefit is that Lab.gruppen’s Class
TD works perfectly under all load conditions. The
output maintains its flat frequency response even into
complex loads with very low nominal impedances.
Reliability is very high, and there is no interference
with nearby RF equipment. Superior efficiency allows
greater power density while minimizing cooling
requirements, yet sound quality matches that of
the best Class B designs.
7.2.1 symmetrical Power
The example PLM 10000Q can deliver power as per
Table 7-1 when all four channels are driven equally.
Load
Impedance
(ohms)
2.0
2.7
4
8
16
Max.
Output
power
(Watts)
2350
2700
2300
1200
660
Table 7-1
7.2.2 Asymmetrical power
The example PLM 10000Q can deliver power as per
Table 7-2 when two channels are driven 3 dB lower
than the other two.
Table 7-2
7.2.3 Power over time
Power ratings given above are applicable to the
example PLM 10000Q running at these levels for a
period of 60 minutes. Due to thermal considerations
in the power supply and elsewhere, it is possible
to draw higher power levels for a shorter period
of time. The graph below illustrates how the rated
power figures are derived and the higher short-term
capability.
Peak output voltage at “max power burst”
Figure
7-1
Load
Impedance
(ohms)
2.0
2.7
4
8
16
Max.
Output
power
(Watts)
2350
2900
2400
1200
660
