My computer had crashed awhile ago so just getting some log-ins back.
Of course agreed the choice is not just of materials but how they are put together, no one could argue that. Tempo Electric had the old Jensen Aluminum Paper in Oil were Tier F and Duelund was tops and other than copper the material was not that different.
The question would be why the Jensen was rated so poor? My guess is noise (poor construction) and Aluminum not sounding as good as copper. The Poly caps though having different faults. Fake sounding.
So does it not make sense to start with at least natural sounding qualities and lower the faults?
I have one full signal of just Duelund VSF (just one) and rest Jensen Copper Foil Paper Tube and other signal all Jensen except last two still vintage. Dynamics and bass is the only real difference and it is big.
For me I feel I have got all I was looking for. The tone of vintage and the dynamics and bass of modern.
So I guess I mean their is nothing special about a vintage capacitor that has not been bettered in every way today.