XINDAK XA8800MNE Instructions Manual Download Page 4

3

The circuit features of XA8800MNE

Designed  as  a  separate  mono-channel  structure,XA8800MNE  is  a  full  symmetrical  current  negative 
feedback Class A amplifier. The main circuit theory and technical features are as following:

The input buffering amplifying stage adopts fast and wide-frequency amplifying circuit with cross coupling compensatory 
structure. It could connect the push-pull amplifying dynatron as Darlington circuit and control base current at a low level, 
ensuring the stabilization of the middle point voltage. Meanwhile, the adoption of transistor Constant Current Source as 
load ensures the steady and liable work on the stage.

Darlington complex structure on the Voltage amplifying stage not only ensures enough voltage gain but also raises the 
input impedance to reach excellent match between the different stages. Besides, the adoption of Cascode circuit offers a 
good solution of the effect on the high frequency by the transistor junction capacitance. Thus the frequency width could 
be raised, the output characteristic curve of the bipolar transistor could be improved, the distortion of this stage could be 
reduced and high stabilization could be achieved.

On the current drive stage, it adopts high power FET to supply drive current for the end stage. The parallel output 
transistors on the end stage could reduce the output impedance, increase the output power, and improve the load 
capability with low resistor. The static working current of 6 pairs high power transistors on the end stage as parallel output 
is  about  300mA  and  each  transistor  works  in  the  special  linear  area  where  current  is  higher.  This  could  eliminate 
crossover  distortion  and  switch  distortion  efficiently  and  reduce  the  output  impedance.  Equipped  with  impedance 
compensatory network including L, Rs, Rz and C on the output terminal, the load of this unit will be closer to pure resistor 
and difficult to cause self-excitation. Meanwhile, it could afford bigger damp to enhance the controlling ability of this unit to 
the loudspeaker.

In  order  to  ensure  the  middle  point  voltage  of  this  unit  approximately  to  be  zero,  high  quality  operating  amplifying 
components, high frequency non-inductance resistor, silver isinglass capacitance and so on are put to good use to the 
loop current servo feedback circuit.

As for the power supply for the complete unit, each channel adopts 600W high quality annular transformer while the other 
parts adopts winding group on the power supply separately. Additionally the power supply for the power amplifying, 
voltage amplifying and protecting circuit are separated: the power supply for the power amplifying part is equipped with 
50A bridge rectifier and 60,000 microfarad Rubycon filtering capacitance and supplies power directly after commutating 
and filtering; the power supply for the voltage amplifying adopts stable power supply with fast speed, low noisy, low 
impedance and strong ability to avoid the “ripple” to avoid the modulating disturbance caused by fluctuation of the power 
on the following stage and make the sound purer.

Additionally, this unit adds protection functions, including power-on delay concussion protection, zero point floating on 
the output terminal, over current and over voltage of the power transistor protection. In order to avoid the noisy when 
power-off, this circuit adds transient release circuit, power-on delay circuit and glittering indicating circuit for protection to 
make this unit more intellective.

2.1 Product Features

Introduction

Chapter 2

XA8800MNE

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Summary of Contents for XA8800MNE

Page 1: ...CLASS A POWER AMPLIFIER XA8800MNE INSTRUCTIONS...

Page 2: ...sk of electric shock to persons Dangerous Voltage The exclamation point within an equilateral triangle is intended to alert the user to presence of important operating and maintenance servicing instru...

Page 3: ...Unplug this apparatus during lightning storms or when unused for a long time 11 Always disconnect your entire system from the AC mains before connecting or disconnecting any cable or when cleaning an...

Page 4: ...ortion and switch distortion efficiently and reduce the output impedance Equipped with impedance compensatory network including L Rs Rz and C on the output terminal the load of this unit will be close...

Page 5: ...al input jack Connect the input signal by signal cable v The speaker binding post Connect it to the speaker by the speaker cable w Power supply input jack and safety cutout jack Connect it to the powe...

Page 6: ...ilable for this machine and make sure of the right channel and polarity 3 Please be very careful when connecting the power cable Make sure the power supply has been cut off before connecting to the ac...

Page 7: ...ly Signal source input phase opposed Speaker wire to channels has exchanged or positive negative reversed Speaker cable is broken Noise too big Left and right channel confused Turn on the sound source...

Page 8: ...7 Unit mm Chapter 4 4 1 Dimensions Specifications XA8800MNE E...

Page 9: ...ut ower consumption Frequency response Signal to noise ratio Distortion THD noise Dimensions W D H Input sensitivity Net weight Shipping weight Supply voltage P 200W ch 8ohm Load 4 4 400W 5Hz 150KHz 1...

Page 10: ...XD3 834 049 SMS No 126 Section 2 East 1 Round Chengdu Sichuan China P C 610051 You can find your nearest authorized distributor and more product information on our website www xindak com...

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