In other words, perfect, pure, balanced  operation is not possible in either this circuit or the SRPP, as neither circuit can deliver a truly balanced  drive to both output tubes.
     So what would the circuit look like if we didn't try to do it on the cheap, i.e. properly? First of all, we know that it would have to provide a balanced  drive signal to both output tubes, ideally equal in amplitude, but opposite in phase and equal in noise content (in phase).

Putting push-pull back into SRPP
      We now leave the goals of constant current source loading and single-ended operation behind. Our new (actually old) goals are clean push-pull operation, with its implication of twice the idle current deliverable into the load impedance and much lower distortion. As we did earlier, we start by taking the circuit apart before rebuilding into something new.

     "Push-pull on the cheap" is how I had earlier described the SRPP, meaning that rather than doing the thing properly by using a gain stage and a phase splitter, we let the bottom triode generate some gain and derive an anti-phase drive signal for the top triode. By the way, this has been done before as shown in the circuit above. In this circuit, the leftmost output tube creates the drive signal for the right output tube by placing a tap in the output transformer's primary that divides its plate swing down to an amount equal to its input signal, but reversed in phase. This circuit is in fact not a bad candidate for a portable headphone amplifier, as the circuit is simple and the output transformer protects the delicate headphones from DC currents. However, this circuit suffers from the same problems that the SRPP does: it gives the slave tube a drive signal that includes the input tube's distortion and a portion of the power-supply noise that the input tube never sees at its grid.

    The above circuit shows a truly balanced  push-pull amplifier. Each tube sees an identical drive signal that differs only in phase. This amplifier consists solely of grounded-cathode amplifiers, as they both provide gain and only their r_p as an output impedance. The transformer performs two tasks: it provides voltage gain (it need not necessarily do so, as unity winding ratios can be employed) and phase splitting. An additional set of tasks that the transformer easily accomplishes is the breaking of ground connections for each secondary winding. Basically, a good transformer is a miraculous device. The problem is finding a good transformer, as most lack adequate bandwidth or hum immunity to work in hi-fi circuits.

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