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POWER AMPLIFIER

KEY FEATURES:

1300 watts @ 8 

2300 watts @ 4 

3200 watts @ 2 

(Measured just below clip level,
with both channels driven)

Compact design, 2U high

Low weight, 10 kg (22 lbs)

MLS™ Switch: Lab.gruppen’s
unique power matching for 
different loads

NEW FEATURES:

Multiple positions gain switch

Intercooler

®

cooling system

with front-to-rear airflow and
easily accessible dust filters

Improved low-end power 
bandwidth

Link connector with XLR-type
connector

Bridged mono outputs in one
Speakon

®

connector

Extruded front panel for 
increased stability

The fP 6400 is a lightweight and space-saving power amplifier, ideal for use 
in high quality touring sound systems as well as in demanding permanent
installations.

Heat and cooling are fundamental problems in extreme high power amplifiers such as 
the fP 6400. Already in 1990, Lab.gruppen patented a high efficiency amplifier, in fact an
evolution of the Class D amplifier. Lab.gruppen therefore call it Class TD. It attains the
same high efficiency as Class D, but avoids its drawbacks. Class D has a power-amplifier
topology using Pulse Width Modulation (PWM) to achieve high efficiency, but it needs a
recovery filter between the output stage and the loudspeaker. Lab.gruppen’s Class TD
amplifiers do not need this filter and this is one reason why the Lab.gruppen Class TD
obtains the same sonic quality as a traditional Class AB amplifier.

Besides the traditionally superb Lab.gruppen sonic performance, fP 6400 offers a full

line of important features:

Regulated switch mode power supply

Today there are many lightweight, switch-mode amplifiers in the market. However, the
unique Lab.gruppen switch-mode power supply technology offers a number of essential
advantages that make it superior to other and seemingly similar power supply designs.
The most important features are the regulated power supply and the extreme power 
efficiency. The regulated power supply easily deals with a very high variation in the AC
mains voltage: it can drop by up to 20% below its nominal level – e.g. to 180 V (90 V)
instead of 230 V (115 V) – without any problem. Perhaps even greater benefits result
from the extreme efficiency of Lab.gruppen amplifiers: only a fraction of the energy from
the AC mains is turned into heat. A regulated power supply also presents some other
sonic advantages, such as better cone control and the same fast response as a conventional
power supply.

Multiple positions Gain switch

To meet the demands for a flexible gain structure in the system, Lab.gruppen offers a
multiple position gain DIP switch. The maximum amplifier gain can be set to all industry
standards: 20, 23, 26, 29, 32, 35, 38 and 41 dB.

Sophisticated protection circuitry, combining:

–  DC protection;

protects against infrasonic signals

–  VHF protection;

protects the loudspeakers against strong very high frequency non-

musical signals above the audible range.

–  Thermal protection;

prevents the amplifier from being overheated. The protection

indicators on the front panel are switched on, as a warning, before the protection 
process is initiated.

–  AC protection;

shuts down the power supply if the line voltage is outside the 

operating voltage.

–  Clip limiter;

prevents severely clipped waveforms from reaching the loudspeakers,

whilst maintaining full peak power.

fP 6400

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