Although late to reply on this older post. Frankly, I never heard better capacitors than the Russian K40Y-9. It is the most musical capacitor I ever heard. Needs 50 hours to start sounding right & first 10 hours is not so good at all.
Coupling caps
I own a Tube Audio Lab WE91 300 amp and a JE labs linestage. They use Jensen aluminum foil POI coupling caps and I am thinking about changing them out.
I have some Jensen paper tube copper foil PIO caps on the way and was also thing about the Dueland copper cast and Jupiter copper foil paper/wax . Has anyone changed coupling caps in any of the TAL equipment or can venture opinions? There a lot of "shootouts" around using different equipment so there are system and listener dependencies in these evaluations.
Personally, I value a smooth midrange as opposed to extended treble as I have some hearing hyperacusis issues that make me very sensitive to upper mids and treble such as sibilance.
I have some Jensen paper tube copper foil PIO caps on the way and was also thing about the Dueland copper cast and Jupiter copper foil paper/wax . Has anyone changed coupling caps in any of the TAL equipment or can venture opinions? There a lot of "shootouts" around using different equipment so there are system and listener dependencies in these evaluations.
Personally, I value a smooth midrange as opposed to extended treble as I have some hearing hyperacusis issues that make me very sensitive to upper mids and treble such as sibilance.