OK, good news is that my TVC (ref version) is finally with me.
the guy who brought it for me from vienna where it was delivered (because of problems with a direct delivery to where i live) also brought his TVC baby that is actually a monster built around Bent-sourced S&B copper trannies and very expensive parts.
there was the third TVC on hand too - the DIY TVC i was raving about here a few weeks ago.
as a reference we were using my current active preamp - EAR 864, not a bad product at all.
the source was avondale modded arcam alpha 5 (a kind of a tweaked classic, 1541->NOS, swing-arm transport etc).
first we listened EAR 864 to get a flavour of a good active valve preamp with output trannies - it sounded very fluid, very organic, with excellent timbre and organic tone. very involving with a good fun factor. it seems that there is a good bass extension and a bit of a roll off in the highest freqs but overal it had a good presentation of music in a holistic way.
then we made a mistake and we connected our DIY TVC based on big ferrite double-C cores.
it made EAR sounding almost broken, that's how superior it was. it had the most tremendous and deepest bass i've ever heard from any preamp and such a noble, organic, real feeling to the music. whatever we tried, it just sounded right and real. forgot to mention, this device was run in using one of the burn-in CDs, don't know if this work at all but it is good to know that as otherwise it had not more than 20 hours on it (as its owner doesn't have a system at the moment).
than we put the very impressive-looking S&B based TVC. it sounded very competent but different to the previous one. it had a tad more transparency thanks to superiour parts used elsewhere (the DIY TVC uses $1 connectors and a plain copper wire, while S&B is fully in silver, WBTs, neutriks etc). it wasn't fully my cup of tea as i could hear a trace of artifice in comparison with the previous one, but the opinions were mixed.
i was really afraid to put the promitheus on after these 2 beasts, especially that it's being used for the first time (zero run-in time). but, it held its own very proud - it unmistakenly showed the virtues and qualities of TVC such as a huge frequency extension and overall control. due to lack of hours, it obviously sounded a bit stiff and unrelaxed, it definitely lacked air and more precise imagery, but it was really surprisiing performance considering i was a bit disappointed with a performance of another promitheus i tried earlier last month. but when i openned the lid, i realized that this is definitely a very different version. not only that i have a ref version connectors and grayhill switch (that is by the way very solid in comparison with the stock one that is too fragile for my taste), but it seems that trannies are different - they look bigger and have a copper coat the other one didn't have.
so to cut it short - promitheus has a great potential and now i will put it aside for next 2 weeks to run it in for 300 hours before adding more impressions.
so this was a very useful evening as it proved several things. first the superiority of passive TVC as a concept was obvious. second, my intuition that S&B trannies are not the latest word in the TVC world was proved with a performance of rather simple DIY TVC prototype that sounded at least not inferior to the S&B one (for me and 2 other guys it was clearly better by a big margin for playing music, not hi-fi). third, i am happy that some of my worries about the promitheus were blown-up and that it is actually an excellent product even regardless of the price it is usually being connected with.
let's see how it will develop so i will write more after 2 weeks.
nick, my sincere congratulations on the excellent development of your product!
gordan
