Single Power Supply 
Horizontal Push-Pull Amplifier
     The Circlotron/horizontal push-pull amplifier requires two floating power supplies per channel. This burdens the design of the amplifier by the  complexity and cost of multiple duplicate diode bridges, and power supply capacitors. And it serves to confuse many tube circuit fanciers; one ground and one B+ are what they want to find in a schematic. So let's give them what they want.
    The separate power supplies have been replaced by large valued capacitors. These capacitors represent a very low impedance at audio frequencies that effectively mimic the original power supplies. Because inductor's impedance at DC is zero, this circuit will not amplify DC signals, but music is not DC. In terms of AC signals, the capacitors will maintain their charge via the chokes, which will not load the output, as the chokes (in opposition to the capacitors) represent a very high impedance at audio frequencies. Imagine that these chokes replaced by large valued resistors or, better still, current sources. The outputs are necessarily floating above ground potential because of the current flowing through the chokes' DCR, which a negative power supply would cancel.

    Now, aren't chokes big, heavy, and expensive, so does this represent a savings or real advance? In terms of better circuit functioning, the advantage of this topology is that the chokes also serve to help reject power supply noise. For those whose thoughts raced ahead to imagine a wonderfully huge power supply noise reduction, you went too far. Yes, in general, chokes are used to reduce power supply noise, but as configured here, the chokes only halve the noise, i.e. reduce by only -6 DB. Key to understanding what is going here is to imagine the chokes replaced by resistors or capacitors or even tubes. All of these devices would serve to define 50% voltage dividers.