Lab.gruppen LAB 2002 Specifications

POWER AMPLIFIER

FEATURES:

2x1000 W into 8
2x1400 W into 4
2x1400 W into 2
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.
2002
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.