Hello,
CuTF is excellent cap and I did rather extensive evaluation which VH Audio posted on their web site:
http://v-cap.com/simon-thatcher.php
The problem with these caps is one - price. So, we do not advertise it. I firmly believe that if platform is good then additions will not spoil it like turbo to very good car. However, if its good car then its good car even without turbo... it just for people interested in speed, I guess
Unfortunatelly, I answer the strange questions when potential customers call us. My most "hated" is question/statement that our single amplifier is bad and if to buy Spectron then only two amplifiers.
I really hate time and time again to explain that there is nothing (zero) proprietery to Spectron. The stereo amp amplifies in single ended mode. When its converted into fully balanced monoblock then this configuration (done right only) "annihilates" amplifier induced distortions and Distortion-free music is gorgeous as many of you know. Note that distortions can be that of class D, class A, tube, transistor whatever - in theory all of them are gone and you ahve distortion free music. Any solid state amplifier in the world can also be configured in this fashion. One demand only: very high part tolerance i.e. high cost which you pay anyway when you buy stereo Spectron.
I do not recommend to change your TTFT caps to CuTF caps as it will be rather expensive.
if to spend money then for something like vibration control (I am in "love" with ULTRA SS by Still Points), power cord and/or interconnects and speaker cable.
One of the greatest pleasure (and pain) of our hobby is to disregard everything manufacturer says and experiment on your own.
Thank you,
Simon