P.S. to my previous post. Think of it this way: As you (ZD) are certainly aware, a fully balanced amp puts out signal voltages on both its + and - output terminals, relative to the amp's ground, those voltages being of equal amplitude and opposite polarity. (In saying that, and in saying what follows, I'm oversimplifying a bit by not addressing the fact that an output transformer is present in the case of this and most other tube amps). The design of the amp in question is apparently such that when it is provided with a single-ended input, one of those two output terminals will be at zero volts relative to the amp's ground (reflecting the fact that zero volts has been substituted for one of the two input signals that would normally be present in the balanced input signal pair). Resulting in the voltage difference between those output terminals being half of what it should be. Resulting in the maximum possible voltage difference between those output terminals (i.e., the clipping point) being half of what it should be, or perhaps a bit more than that due to the lessened amount of current being demanded of its power supply.
Put simply, half of the output stage for each channel isn't being used. Visualize it (conceptually) as two amplifiers for each channel, one for the + and one for the -, with one of them receiving no input, and therefore providing no output.
Best regards,
-- Al
Put simply, half of the output stage for each channel isn't being used. Visualize it (conceptually) as two amplifiers for each channel, one for the + and one for the -, with one of them receiving no input, and therefore providing no output.
Best regards,
-- Al