Perreaux Prisma 350 - Manual (Page 19)

19
Multiple
Protection
Systems
The 350 is equipped with a number of protection systems, isolated from all
signal carrying circuits via opto-couplers, to protect both itself and ancillary
equipment.
DC Offset Protection
This system senses if any direct current (DC) is present at the 350 output
terminals and disconnects the output to avoid potential speaker damage. DC
may be present due to ancillary equipment feeding DC into the input or an
amplifier fault.
Short-Circuit/Overdrive Protection
This system senses if there is a short circuit across the 350 output terminals and
disconnects the output to avoid amplifier damage. It also senses if the 350 is
being driven outside acceptable operational parameters. An example of this
would be driving a 1Ω speaker at very high levels.
Note: After the short circuit or overdrive source is removed, the 350 must be
turned off then back on to reset and resume operation.
Thermal Protection
This system senses if the 350 is overheating and disconnects the output until a
safe operating temperature is reached, at which time the unit will automatically
resume normal operation.
Earthing Perreaux engineers pay particular attention to designing the product to ensure
maximum separation between internal signal and power earths, only meeting at a
central starred point.
Earth
Isolation
Switch
The toggle switch on the rear of the 350 allows the internal circuitry to be
isolated from the mains earth, whilst still maintaining an earth connection to the
chassis. This ensures the potentially fatal practice of using an AC cord-set with
no earth connection, to alleviate system hum, is not required.
Highest
Quality PCBs
and
Components
Quality fibreglass PCBs, featuring heavy copper tracks and high-grade
components, are used throughout the 350. This provides added stability under
variable thermal or electrical loads and assures maximum signal integrity,
separation and product life.
Bi-Wiring
Made Easy
Dual pairs of binding posts per channel allow bi-wiring of speakers to be
conducted easily.
Soft-Start
Circuitry
The 350 utilises soft-start circuitry to protect the fuses and/or circuit breakers in
your home’s mains power supply. Without this circuit, the huge inrush current
required to charge the 60,000µF of power supply smoothing capacitance can
blow the fuses or trip the circuit breakers.
Highly
Powered
Capable of continuously delivering 350W
RM S
into 8Ω (600W
RMS
into 4Ω), the
350 is highly powered. Utilising eight high current Toshiba MOSFETs per
channel, the 350 handles even the most difficult loads with ease.