Quote:
Theriotically speaking, the diode that sounds best is the one that has least change in foward voltage as current varries.
Schottky didoes have lowest foward votlage and for the same current ratings the change infoward votlage is less.
I agree in theory.
However the diodes only turn on when the supply voltage exceeds the charge on the PSU caps.
The PSU caps voltage is variable on transient demand so the current charge time is variable based on the ESR.
The ability of the PSU to supply current is a trade off between transient demand and recovery time.
Ie if the recovery time is longer than the transient demand the supply will SAG.
NB that is also mentioned in the idea of the Driver/pre tubes supply being drained via the output stage causing variable supply voltage on the driver in transient.
The switching and noise as shown by Toshiba are greater with fast response/sharp recovery. That is supposed to be the theory behind tube rectifiers. Its interesting to note that tubes have high voltage drop in the forward direction, yet some people prefer them.

Its also interesting to look at old circuits running in pentode with tube rectified supplies.
It is possible to filter using HF filters, but again in theory the PSU is only supplying DC. In my experience the PSU has a marked effect on sound quality. From the point of a diode never turning off its interesting to look at back EMF from inductors including output transformers and the effect on the PSU and output tubes.
Regards
M. Gregg