FEATURES:
◆
2x1000 W into 8
Ω
2x1400 W into 4
Ω
2x1400 W into 2
Ω
at clip level with two
channels driven
◆
Compact design,
2 U high (88 mm)
◆
Low weight
◆
MLS™ switches for each channel
offers power matching into
different loads without increased
power losses
◆
Electronically balanced
inputs
◆
LED indicators show
output voltage and
headroom
◆
Output cooled by Intercooler
®
◆
Two proportional speed fans
◆
Independent protection circuitry
◆
Short circuit protection
manages long-term short-circuit
operations
◆
DC protection
◆
Clip limiter
◆
VHF protection
The LAB 2002 is a compact (2 unit
high) light-weight (10 kg) power
amplifier designed for high quality
touring sound systems and fixed
installations.
The chassis is made of 2 mm-black
anodised aluminium, with a 4-mm
thick front panel. The switch-mode
power supply is placed just behind the
front panel to ensurenoise free opera-
tion. Two proportional speed fans cool
both the power supply and the two out-
put channels with airflow from front to
back.
The switch-mode power supply is
the modern solution of the weight and
size problem. With switch technology
operating at a high frequency, it is pos-
sible to use ferrite transformers instead
of heavy iron transformers and large
electrolytic capacitors.
Switch-mode technology has been
applied in power supplies in TV-sets
during the latest 30 years. But in the
LAB 2002 the power capacitivity is 20
times larger.
We have designed the LAB 2002 to
obtain the same characteristics as a
conventional power supply. Thanks to
the switch-mode power supply it is
easy to get the DC-rail voltage stabi-
lised. This is made by controlling the
magnetic energy in the ferrite trans-
former with a pulse width processor
and magnetic ”Flux Sense” windings.
The LAB 2002 has an upgraded ver-
sion of the well-known switch mode
output stage from the LAB 2000. A sol-
id copper cooler, called Intercooler(r),
originally designed for our LAB 1300
power amplifier cools the power tran-
sistors. Lab. gruppen’s specially de-
signed thermal feedback circuit pro-
tects against thermal breakdown.
Short circuit protection;
The LAB 2002 is completely short-cir-
cuit protected -even in reactive loads.
The LAB 2002 is equipped with Lab.
gruppen’s specially designed short-cir-
cuit protection, which permits very
high peak-currents,, but still holds the
transistors within the so-called ”Safe
Operation Area” at the present operat-
ing voltage. This makes it possible to
run loudspeakers with impedance vari-
ations, which are considerably lower
than the lowest permitted impedance
of the power amplifier.
Six more protection circuits, which
are separate for each channel, protect
the LAB 2002 and the loudspeakers:
DC protection;
There are two types
of D.C. protection; Fuses on the supply
branches of each channel (this is an
IEC 65 requirement) and a Crowbar
bar protection that shorts the output.
Thermal protection;
Protects the
amplifier from over heating and
causing damage to the output stages.
The indicators come on before the
signal is muted.
Clip limiter;
Prevents severly
clipped waveforms from reaching the
loud speakers, but maintains full peak
power. As a by product, when the
amplifier comes out of a protect condi-
tion, the output level has a slow rise
time. The effect is like turning the gain
up slowly.
VHF(Very high frequency)
protec-
tion; Protects the loudspeaker against
non-musical signals outside the audible
area.
AC protection;
shuts down the out-
puts if the line voltage is outside the
operating voltage of the LAB 2002.
All electronics are mounted on four
modules. The modules are easily acces-
sible for replacement or repair, etc.
POWER AMPLIFIER
2002
