On Jul 1, 2024, at 15:08, j.postma8 via groups.io <j.postma8@...> wrote:

?Henry, I basically agree with your first three paragraphs. But where you go wrong is with your assumptions and calculations. The capacitance drop is not just 0.1uF at 22V, but it drops to just ~3uF! This results in a clearly audible and measurable decrease in sub-50Hz frequencies. Just tested and verified this with a Murata 22uF 25V X5R size 1210, which decreases to ~4uF. If I would want to keep an effective ~50uF capacitance with MLCCs, I would have needed almost $10 worth of huge 2220 size X7R caps, whilst an 47uF Panasonic EB series elcap would cost me less than $30. For me, X7R, and X5R even more so, remain a no-go.

THD @ 20Hz measured 0.2% at 400mV AC input with the Murata MLCC. Inaudible at this frequency, AFAIK.

As usual, YMMV.

Jan