4
DESCRIPTION
Audison LRx 2.150, LRx 2.250 and LRx 2.500:
Car stereo power amplifiers characterised by excellent musical performances, small size and outstanding
energy reserve.
Their power supply stage is made with 70A MOSFETs (one pair in LRx 2.150, two pairs in LRx 2.250 and
three pairs in LRx 2.500); it is PWM, stabilised and oversize.
Input stage is provided with a special circuit (LNS) which permits the system disturbances rejection,
reducing noise that is usually due to the vehicle electric parts (alternator, electronic injection, etc.),
without altering musical signal quality.
Driver stages are characterised by a very linear circuitry.They have coupled differential transistors and an
A Class complementary voltage amplifier. Power sections have Darlington configuration with high gain
and SOA (Safety Operation Area) BJT TO247. Thanks to their great capacity to supply current, these
amplifiers can easily drive even the most difficult loads and satisfy whatever power needs.They can give
powers between 80 and 200W per channel with 4 Ohm load and between 110 and 330W per channel at
2 Ohms in continuous mode. Powers range increases in mono mode (bridged) and it is between 220 and
660W on 4 Ohms. Differently from what occurs with other amplifiers, LRx 2 are not blocked by protection
systems immediately below 2 Ohms. Their exclusive “Overload Limiter” circuit allows them to go on
working, limiting output power and pointing out how hard the applied load is by the “Limit” LED
blinking.
Their big power reserve, their constant control at low frequencies and their exquisite timbre qualities
make them ideal components to realise systems designed to attain outstanding musical features and
very high sound pressures (SPL).
LRx 2 have two bypass HI-PASS and LO-PASS filters with non independent frequencies. Their
configuration is Butterworth, 12dB/Oct.
A switch permits to decide whether to send the HI-PASS section or the LO-PASS one to power stages.
In case LRx amplifiers are used in extremely difficult conditions (very low loads) or in installations where
space is too narrow and their heat sink cooling is not enough, they can be employed together with
CLK2 cooling system (optional). It is a system made of two units to apply onto the amplifier sides; each
of them is provided with an electronically controlled fan that allows the amplifier thermal stabilisation
(see “CLK2 – LRx Cooling Kit”).
LRx 2 protection includes:
• RGP (Resettable Ground Protection) circuit; in case a short circuit occurs between loudspeakers outputs
and car chassis, it detects a high current flow in the pre-input ground and acts by putting the amplifier
in stand-by, protecting its circuitry;
• a device against short circuits and against DC in the outputs, to protect loudspeakers;
• a device that detects the amplifier temperature excessive increase and stops its functioning until optimal
conditions occur again.
Once the causes which implied protection circuits intervention have been checked and solved, the
amplifier is reset by switching it off and on again.
The amplifier is also provided with another general protection which is insured by an internal strip fuse,
very easy to reach.
Optional:
- CLK2 cooling system is available upon request.
21
INSTALLATION
LOGO ROTATION
1 - Remove the transparent
cover which protects
controls and then the 4
screws which block the
metal plate by using
multispanner.
2 - Remove the plate without damaging the
silkscreen printed panel which will have to
stay on. We suggest that you seize both
plate grips with your hands and pull them
by blocking the silkscreen printed panel
with your fingers against the amplifier
chassis at the same time. This will permit to
remove the plate from the panel without
damages.
3 - Remove the strip with
audison logo.
5 - Mount the plate
back by fixing it
through the screws;
then, re-assemble the
transparent cover
which protects
controls
4 - Put the strip back again after turning it,
so that audison logo is upside down.
