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Special Design
Features
Rugged Build
Quality
Mechanical strength has been a hallmark of Perreaux products since th
company first started production back in 1974. The concept behind the physica
design and construction is that each structural member should contribute to bot
rigidity and performance.
Stiff Power
Supply
The E160 incorporates a custom designed, toroidal power transformer,
employing heavy gauge wire that reduces copper losses to a minimum. A
electrostatic shield prevents AC line borne interference from entering the signa
path. The power supply filter capacitors, totaling 20,000μF have exceptionall
low inductance and internal resistance. They charge and discharge in respons
to load demand far more rapidly than conventional storage capacitors and ar
capable of delivering the instantaneous current required by the output stages,
providing optimum dynamic range and transient response. The wiring from th
power supplies to the output boards is designed for unimpeded transmission o
the required current and voltage and utilizes heavy gauge, copper wire cables.
Since power supply leads radiate at signal frequencies, all wiring is carefull
loomed to minimise this effect.
Hybrid Class
A/AB
The bi-polar transistors used in the E160 are run in Class A mode. This avoids
the crossover notch distortion and the resulting odd-order harmonics present, to
some degree, in all other classes of operation. The devices used in the E160
output stage are MOSFETs, which with high quiescent current circuitry, are ru
in the equivalent of Class A to 10 watts. Beyond this point the output class is
technically Class AB (hence the hybrid nomenclature), but with a majo
difference. The combination of MOSFET characteristics and their application i
this circuitry, result in crossover distortion so minimal that it is virtually non-
existent.
MOSFET
Output Stage
The E160 output stage takes full advantage of the unique qualities of MOSFE
devices and in many ways they are superior to bi-polar transistors. A majo
advantage is their tendency to draw less current over a large section of the powe
bandwidth as their temperature rises (Negative Temperature Coefficient), henc
self stabilising thermally, whereas bi-polar transistors draw more current as thei
temperature rises (Positive Temperature Coefficient) and protection circuits
become mandatory to prevent thermal runaway and eventual self destruction.
MOSFETs have the ability to swing fully across the amplifier’s internal DC
voltage and are therefore true "rail-to-rail" devices. Using MOSFETs
encourages the highest performance from the balance of the internal amplifie
circuitry.
Earthing
Perreaux engineers pay particular attention to designing the product to ensur
maximum separation between internal signal and power earths, only meeting at
central starred point.
