New tube amplifier push-pull amplifier circuit

Only one channel is given here. The pre-stage is composed of 6N11.
The SRPP circuit has the characteristics of low output impedance, small distortion, and good high-frequency response. The inverter stage uses
a commonly used long-tail inverter circuit. Detailed analysis will not be done here. Readers can refer to relevant articles. The final stage
is composed of two output tubes forming an anti-parallel push-pull circuit. The wiring of each electrode of the output tube
is different from the wiring of the final tube of the usual push-pull amplifier. In addition, there must be two sets of power supplies, each of which is independent. It is not
difficult to see that the so-called anti-parallel push-pull circuit is just a set of power supplies added to the ordinary push-pull amplifier circuit
, and then the polarity of one of the tubes is reversed, and then
the positions are aligned. Just replace it.
    The biggest feature of this circuit is that the output transformer has an extremely simple structure, it is an autotransformer, but its performance is very good. Because
the output transformer has only one coil, the so-called primary and secondary are just tapped from it. Therefore, the coupling is tight and the leakage inductance is small. There is
no need for mezzanine, segmentation, or cross-winding. And because there is no DC passing through the load, it is used With the same volume of iron core, a larger
inductance can be obtained.