now consider the same amp with an ss rectified psu with such efficiency (that all ss rectifiers proudly have) and feed the same magnitude of signal that it is forced into clipping, now due to the ss rectifiers efficiency, the psu can cope and maintain current versus voltage thereby forcing the amp into hard clipping.
i am not sure i understand exactly what you mean, but for a tube rectified amp, replacing it with ss rects would mean that power otherwise lost in the tube rectifiers is now available for the amp,some 15watts at least! that is why operating point changes as what arnoldc stated in his post:
what you heard in sonic difference is the change in operating point, you increased the B+
btw, clipping is a function of input signal! all amps can be driven into clipping due to the fact that its psu does not posses infinite power! as with all amps be they tube or ss, if we want to avoid clipping, then we should not feed the amp signals that it can not handle! sure thing, tubes clips gracefully than ss!
i compared tube and ss rectifiers on two counts, efficiency and transformer untilization! there is no arguing if you like the sound of tube rectified amps or vice versa, after all it is your ears that matters.
with today's ever increasing cost of meralco power, looking at them from the perspective of efficiency makes sense, at least to me!
more on the traffo side:
since tube rects are almost always fed from a center-tapped winding, there is always that unbalanced coil resistance/impedance because there is an inner and an outer winding! this condition creates a magnetising effect due to that fact that half of the time, a half segment is doing nothing, ie., not conducting current. this explains in part why tube rectified traffos run very hot!
that is why i make my traffos with biffiliar secondary windings, these way, both halves are of equal resistance!