An old thread, but a worthy topic.
I also have only good things to say about the V-Cap CuTF. I've added 0.1 uF CuTFs to my BeePre (in parallel with 10 uF ClarityCap CMRs) and to my Stereomour II-45 (in parallel with 4.7 uF CMRs and as replacements for the F104K caps between the plate of the 12AT7 and the grid of the output tube).
To my ears and in my setup, the V-Cap CuTFs make an extraordinary improvement. They are still new (less than 50 hrs of playing time), but from the first moment after installation they have sounded great and should only improve with time. The biggest improvement came from adding them to the BeePre. What improved? Everything! soundstage, imaging, detail and musicality ... you name it. I'd rank the improvements as comparable to the shunt reg upgrade on the Stereomour -- by far my favorite of the three SII upgrades. It is not a subtle improvement that you need to listen closely for -- it is an obvious improvement. String instruments in particular (cello and violin) sound superb and natural. In comparison, replacing the large stock coupling caps with ClarityCap CMRs made a noticeable improvement in detail, but nothing to rave about.
I should add that I suspect how much improvement can be had from the CuTFs depends on the quality of the upstream signal. Upstream distortion/noise that becomes part of the music signal is not going to disappear. In my case, I \had already taken steps to minimize distortion/noise from my media server and dac using Audiophile Optimizer on my media server (Intel NUC), high quality power supplies (SOtM and a linear psu from Uptone Audio for my USB bridge) and locating the media server away from my router, and keeping both away from my Dac and amps. These upstream steps significantly reduced treble glare and sibilance.
The V-Cap CuTFs are insanely expensive, but IMHO insanely good.
cheers,
Derek
