With Blackgate disappearing over the horizon we need to find a new solution or fall back on the dreaded electrolytic! A key measurement is dissipation factor which measures how much of the signal gets soaked up by internal losses (power supply ARE in the signal path). Some sample DF measurements at 100hz :-
Rubycon Electrolytic 47uf/450v: 0.061
Panasonic 47uf/450v: 0.035
Blackgate 22uf/350v: 0.026
Obbligato Power Cap 47uf/500v: 0.00015!
You CAN hear the difference. Purpose designed Obbligato Premium Film Power Supply Film Caps. Not oil filled. Non-polarized si non-directional. Although rated at 47uf/500v and 100uf/400v these are not like electrolytic's that pop when over voltaged and can be safely used in circuit to rated maximum. Constructed axially for the lowest possible inductance. Wound tight with no voids.