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DC Offset Protection 

This  system  senses  if  any  direct  current  (DC)  is  present  at  the  750  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 750 output terminals and 
disconnects the output to avoid amplifier damage.   It also senses  if the 750 is  
being  driven  outside  acceptable  operational  parameters.    An  example  of  this  
would be driving a 1

 speaker at very high levels. 

Note:  After  the  short  circuit  or  overdrive  source  is  removed,  the  750  must  be 

turned off then back on to reset and resume operation. 

Thermal Protection 

This system senses if the 750 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  750  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 750.  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 allow bi-wiring of speakers to be conducted easily. 

Soft-Start 

Circuitry 

The 750 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 750W

RMS

  into 8

 (1300W

RMS

 into 4

), the 

750 is highly powered.  Utilising sixteen high current Toshiba M OSFETs, the 
750 handles even the most difficult loads with ease. 

 

Содержание Prisma 750

Страница 1: ...Prisma 750 Monoblock Power Amplifier Owners Manual...

Страница 2: ...change products or specifications detailed herein at any time without notice and does not make any commitment to updatethe information contained herein No licenses to patents or other intellectual pr...

Страница 3: ...m and electronic reliability with a functional yet elegant appearance that reflects the care and craftsmanship applied during all stages of construction Features at a Glance Balanced and Unbalanced in...

Страница 4: ...posing the 750 to extremely high or low temperatures The 750 should be connected to a mains power supply only of thetype described in the operating instructions or as marked on the rear of the unit DO...

Страница 5: ...Caution The 750 is an extremely high powered convection cooled amplifier The finned outer heat sinks may become very hot when delivering high volume levels to avoid injury care should be taken not to...

Страница 6: ...ons 11 4 4 4 4 Rear Panel Functions 12 5 5 5 5 Special Design Philosophies 16 6 6 6 6 Special Design Features 18 7 7 7 7 Maximising System Potential 20 8 8 8 8 The Power MOSFET 22 9 9 9 9 Care and Mai...

Страница 7: ...lifier could be tipped upside down and the bottompackaging removed If opened in this manner please ensure that you turn the contents over again Note Be very careful to secure the unit if you are plann...

Страница 8: ...h a cloth or similar Please do not mount the 750 directly onto carpeted surfaces As a rule of thumb allow 80 100mm 3 4 inches around all sides of the product and mount the 750 on a flat surface ensuri...

Страница 9: ...unbalanced RCA input at the rear of the 750 and set the input configuration toggle switch at the rear to the correct position Note Try to keep all interconnect cables as far from loudspeaker cables as...

Страница 10: ...he volume Slowly increase the preamplifier volume control to achieve a comfortable listening level CONGRATULATIONS Now that you have achieved your first objective sit back relax and please read the re...

Страница 11: ...e OFF position or power not being supplied to the mains power cord e g unplugged switched OFF at the wall socket tripped circuit breaker etc Standby occurs when the unit is connected to the mains supp...

Страница 12: ...important that the 750 be operated from the correct AC mains voltage This unit is factory set for the voltage applicable to the original country of destination The 750 will operate satisfactorily with...

Страница 13: ...itch DOWN connects the internal signal earth to mains earth and is the normal position Setting to UP disconnects the signal earth from the mains earth Note Activating this switch has no effect on chas...

Страница 14: ...outputs The connectors are high quality gold plated sockets which are highly conductive corrosion resistant and provide less potential for corrosion induced distortion Refer to Chapter 13 Specificati...

Страница 15: ...mising System Potential Speaker Output Terminals The 750 is equipped with two sets of output terminals to enable easy hook up for bi wiring of loudspeakers or additional loudspeakers All terminals are...

Страница 16: ...design perspective only The concept of less equating to more has been at the heart of all Perreaux audio designs for more than a quarter of a century Minimalist Electronics We wish to maximise the qu...

Страница 17: ...products on the planet We let form and function blend together in perfect harmony This surely is the essence of true minimalist utilisation Minimalism in a Wider Context John Pawson writes Clearly si...

Страница 18: ...crossover notch distortion and the resulting odd order harmonics present to some degree in all other classes of operation The devices used in the 750 output stage are MOSFETs which with high quiescen...

Страница 19: ...hs only meeting at a central starred point Earth Isolation Switch The toggle switch on the rear of the 750 allows the internal circuitry to be isolated from the mains earth whilst still maintaining an...

Страница 20: ...e input sensitivity so that when the same input signal is provided to each of them the output level will be exactly the same This can often be done with one power amplifier connected to the tweeters a...

Страница 21: ...e with your particular priorities The best advice we can give concerning the choice of loudspeakers is establish clearly in your mind your requirements listen to many makes and models and if at all po...

Страница 22: ...the device is effected by the application of a smaller but nevertheless significant amount of power to the controlling element Whereas in the power MOSFET the control of the power through the device i...

Страница 23: ...s in a power transistor This is related to thermal runaway In order to understand this one must imagine that the chip silicon inside the power transistor is in fact many smaller transistors connected...

Страница 24: ...slow This means the distortion products in the signal of say a fast transient will not travel through the negative feedback system into the output stage fast enough to cancel at exactly 180 degrees o...

Страница 25: ...o the surface Stubborn dirt may be removed by the application of a small quantity of methylated spirits applied directly to the cleaning cloth only and reworking the effected area Front Panel The 750...

Страница 26: ...it will be repaired or replaced at our option without charge for either parts or labour The warranty does not apply to any unit that has been misused abused or altered Any unit that is not performing...

Страница 27: ...ail Perreaux Industries Ltd PO Box 305 Mosgiel Dunedin 9053 New Zealand E mail info perreaux com Alternatively complete the online Warranty Registration Form on our website www perreaux com 5 Year Ext...

Страница 28: ...must be employed to negate these effects on low level signal equipment Another good practice to adopt is to keep all signal leads away from power leads The practice of neatly tying excess leads togeth...

Страница 29: ...experiencing a problem such as one channel not working or a noise in one channel it is good practice to adopt a method of isolating the problem to a specific item or area This practice will assist in...

Страница 30: ...ow swapping them at the amplifier output If the fault now appears in loudspeaker B then that loudspeaker lead is at fault go no further If the fault appears in loudspeaker A then loudspeaker leads are...

Страница 31: ...ut at a minimum volume setting Only increase the volume after the connections have been changed Should the fault prove to be in the amplifier it will be necessary to determine where the fault actually...

Страница 32: ...estore speaker cablesto original connections Fault in loudspeaker B Swap amplifier source input channels Loudspeaker A at fault YES NO Loudspeaker cable at fault Fault in loudspeaker A Swap source out...

Страница 33: ...at 0 040 THD 1300WRMS into 4 continuous driven from 20Hz 20kHz at 0 070 THD Frequency Response 5Hz 40kHz 0 25dB Total Harmonic Distortion THD N Typically 0 008 1kHz into 8 20Hz to 20kHz 0 040 into 8...

Страница 34: ...everyone is familiar Actually frequency response is a misnomer technically it should be called amplitude response versus frequency for it describes how uniform the amplitude or strength of signals of...

Страница 35: ...ak the 750 can easily meet any challenge music can present to it whether instantaneous or continuous To be specific it can deliver high power into low impedance loads and provide great dynamic headroo...

Страница 36: ...36 14 14 14 14 Physical Dimensions...

Страница 37: ...ails For more information please contact your Perreaux dealer or contact Perreaux Industries Ltd PO Box 305 Mosgiel Dunedin 9053 New Zealand Ph 64 3 489 2975 Fax 64 3 489 2976 E mail info perreaux com...

Страница 38: ...38 Installation Notes...

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