Simple and supreme 200W fully symmetrical power amplifier

In many fever articles in recent years, the supremacy of simplicity has always been a topic that many enthusiasts talk about. What is introduced below
is such a completely symmetrical power amplifier circuit with simple circuit and excellent effect.
    The circuit principle is shown in Figure 3-49. o STK6004C is an ultra-high-power thick film circuit manufactured by Japan's Sanyo Company.
There are three groups of high- current totem pole output pairs inside. Each group has a withstand voltage of not less than 200V and a current of not less than 15A. , filled with
transparent silicone gel that has good thermal conductivity, has its own heat dissipation and is insulated from the internal circuit. Because the internal circuit is very complex and part of it has been solidified, this article
will transform it and take out the essential part to become the circuit in Figure 3-50. Well put it It is arranged in the rear stage (third stage) of the fully symmetrical power amplifier.
The first and second stages both use ordinary differential circuits, and resistors are used as loads at all stages. They are characterized by simple circuits, low distortion, wide
frequency response , and good sound quality. 6 Because it uses a self-installed switching power supply with multiple protections, the protection circuit of this power amplifier is particularly simple. 6 Circuit