Actually, I'm now running the CAST in my preamp and a combination of Mundorf Supreme and Supreme Silver/oil in the following low frequency equalizer/buffer. I find that when I connect the preamp directly I get more of the CAST sound (natural, quiet, tonally accurate) with bass that is slightly overstated. When I put the EQ/buffer in line between the preamp and amp, the Mundorfs give me more spaciality and 3D soundstage together with the Duelund tonality, and reduce the bass just enough that it is no longer overpowering. I experimented a bit and found that the use of ~10uF of Supreme together with .33uF of silver/oil gives me the best combination of detail and smoothness in the EQ application.
So I'm finding that I like the Duelund/Mundorf combination best at this time. YMMV
So I'm finding that I like the Duelund/Mundorf combination best at this time. YMMV