The amplifier shown is slightly different from the others because it does not use push-pull output. Its Class B output uses only one EL84 tube in each channel, but still it provides excellent sound quality with good power, approximately 12 W.
The circuit uses three valves in each channel plus one full-wave rectifier.
In addition to the tubes, the critical components of this circuit are the transformers. In particular the output transformers must be of types for single output and not in push-pull.
The circuit has dual volume control and a balance control between the channels. A tone control network on each channel also enables this feature on the amplifier.
The components, especially the capacitors, must have working voltages compatible with this type of application. In figure 1 we have the complete circuit of the amplifier.
