Diode rectification is far more efficient than a tube rectifier and responds to changes in current draw far quicker. So the attack on loud notes causes ‘sag’ with a tube rectifier that doesn’t occur with diodes. You can simulate sag with resistors in a diode rectifier circuit but most amps don’t bother. Weber make solid state rectifiers that fit in tube bases that allow a lot of ‘sag’ but are more reliable. So there is an affect on the sound, but mainly on the big transients.