Jet, I believe we are talking about the same thing when you say the CAST caps sound "dark" and I say they are "a bit lacking in air and high-frequency extension." I could hear this when I put the first one in but it became more of a problem when I added a second and then a third CAST cap. Of course, the treble colorations may not be a problem in the context of a particular system.
Since my post a few days ago about V-Caps, I did some reading on the internet about V-Caps and a number of folks described the TFTF caps as clinical, cool or bright, especially when a system has 4 or more. I find this quite odd because it doesn't match my experience at all. Perhaps this has something to do with the fact that I bought all of my TFTF caps during the first 6 months or so of their introduction. Maybe something changed later on in the design or construction. Or maybe other people posted their feelings prior to the caps being fully broken in. The TFTF caps took a long, long time to break in. Somewhere around the 450 hour mark they went from lean, bright and glassy and began a transition over the next few hundred hours to warm and rich in the lower midrange and slightly soft in the treble. The final sound is pretty much the opposite of what I read from a number of internet posters. In contrast, the CuTF V-Caps never sounded bad during the breakin process; they started out sounding good and just got better and better.
I am not trying to start an argument with people who tried V-Caps and didn't like them. I am simply describing my experience.
