Word that both output tubes are run open loop, with now not even local poor remarks. There are cathode resistors, but they're bypassed through capacitors. The cathode resistors consequently are simplest for getting a predictable and strong dc working point. Observe that every transformer is classified as "four ω". Wiring the outputs in parallel might yield 2 ω. Wiring them in collection could yield twice the voltage, however at eight ω. You get the identical strength capability both way, however in collection they can supply more strength right into a 8 ω load. In contrast to what others have said, this isn't a push-pull stage. Despite the fact that drawn as mirror pics, the 2 tubes are driven identically. They every drive a separate transformer. The two transformers positioned out the identical sign.