Linn C 4200 Stereo Amplifier User Manual


 
2
CHAKRA
Power Amplifiers
Owner’s Manual
English
Introduction
AAKTIV* operation
All CHAKRA amplifiers support AKTIV operation.
Standard 'passive' crossovers are driven by the audio signal itself and so some of the
signal is effectively lost. AKTIV crossovers are powered by the SMPS (see above) and
therefore much more of the audio signal is delivered to the loudspeaker. They are also
able to exert a much greater degree of control over the signal and these qualities
combine to provide a significant improvement in sonic performance over standard
operation.
Your Authorised Linn Retailer can carry out the AKTIV conversion of any CHAKRA
amplifier channel with the insertion of a specially designed Linn AKTIV module.
Protection
Over-current protection
If the output current goes above the amplifier's designated safe operating level, the
affected channels shut down instantly for a few seconds in order to protect themselves
and the loudspeaker drive units to which they are connected.
Over-temperature protection
Similarly, if the amplifier's temperature rises above its safe operating limit, the
affected channels will cease operation until the temperature drops to a safe level and
will then automatically resume.
*The term 'AKTIV' refers to the proprietary Linn active modules and loudspeaker configuration.
Features
CHAKRA amplifier technology
The CHAKRA topology uses an array of large bi-polar transistors as
'boosters' around a monolithic (single chip) amplifier IC (integrated
circuit). Linn's execution of the monolithic to bi-polar transition is
unique, and a patent application for the design has been registered.
When output current is less than a few amps, all the power output
comes from the monolithic IC, maximising the speed and linear
properties of this design. At higher output currents the bi-polar transistors provide the
majority of the output current, leaving the monolithic to operate well within its
capability and able to correct any error instantaneously.
The topology is very compact, reducing the circuit area and length of the signal path
and is also highly efficient, producing much less heat than traditional designs.
Switch mode power supply
A 'switch mode' power supply (SMPS) is incorporated into all CHAKRA models. SMPS is
an electronic power supply which converts and regulates the incoming mains voltage,
and also provides the internal audio circuitry with excellent electrical isolation from the
outside world. The SMPS replaces the bulky, heavy and noisy transformer, as well as a
number of other sizeable components.
The major benefits of SMPS over conventional power supplies include: small size, high
efficiency, fast response, high mains input tolerance, good load tolerance, low acoustic
noise and, with its much reduced material use, environmental friendliness.
Also, SMPS does not emit distortion into the local mains supply, as conventional large
power supplies tend to do and if you upgrade from an amplifier with a conventional
power supply to the CHAKRA amplifier, aside from the benefits of the improved
amplification, the sound of your entire system will almost certainly improve as a result
of the cleaner mains supply.