3
XA8550 is a Dual Channel Power Amplifier. The appearance is both simple and elegant. Besides, the
sound of this unit is fast with high analysis ability and full musical taste on the base of good balance.
The circuit features of this unit are as following:
Power Amplifying Circuit
The power amplifying circuit of the power stage is the classical current negative feedback circuit with
full symmetrical and full complementary structure which is well appraised in audio field. The main
advantages of this circuit are low distortion, wide dynamic range, good controlling ability, steady work
and euphonic tone color. The current amplifying circuit is three-stage Darlington circuit, whose first
stage adopts MJE350/MJE340 geminate transistors and second stage adopts Toshiba
2SC517/2SA1930 geminate transistors. The output transistors are three pairs of SANKEN
2SC3264/2SC1295 high current geminate transistors. Thus this amplifier has powerful drive. Power
Supply System
This unit adopts two 300W annular transformers as power supply, so 600W power in total. Besides,
the rectifiers are 50A/400V bridge rectifiers. The main power supply filtering capacitances are
82000uF/63V Rubycon electrolytic capacitances.
RCA input port
The two pairs of RCA ports are parallel connected. When there is signal on the input ports, on the
output ports the signal could be transmitted to the bass or to the second amplifier to achieve the partial
tone on bi-amplifiers.
Output port
Considering the special connecting way for partial tone, two pairs of output ports for loudspeakers are
offered on each channel.
2.1 Product Features
Introduction
Chapter 2
XA8550
XA8550T
