I am using vintage globe 45s with WE 417A as drivers, stock rectifiers.
I wonder if purrin is reading this, it seems that my demo 4-45 is not exactly like the ones in the photos. Mine is a two box amp with separate power supply. At the main box there are no protruding transformers. I wonder if this is the same as the current production ones.
Anyway, my immediate impressions after about 2 hours casual listening are very positive. I had the amp run for an hour. It should be fully burned in as this is Craig's demo 445 which was used in shows and meets.
I think that the 445 is really special with the HD800. It drives the HE6 very well too despite high power demands. The one very pleasant improvement upon the WA5 is it is simply smooth. There are no rough edges. The highs, mids and lows are very well put together, and flow as a cohesive whole. And the soundstage is magical and holographic. I think it made my HE6 sound like what the WA5 did to the HD800 as regards soundstage. The HD800 sounded out of my head for almost any song I threw at it, even mp3s on Spotify, whereas the WA5 only had such an effect on certain good recordings like Cassandra Wilson's Blue Moon.
Both amps are detailed but the 445 is slightly more so in a more realistic way. Sometimes I think the WA5 renders micro details in the highs better as the 445 sounds a bit recessed in the upper mid range to the highs. I suppose the detail is there but it is just recessed in volume. I can understand why some might think the 445 is less detailed than some other top end amps. The word is smooth, not detailed. I do have an organic sounding DAC so I think the details are even more smoothed over. In comparison with the WA5, it has noticeably more "macro" detail, letting you get a good view of the entire soundscape rather than focus on one or two micro aspects. It is therefore "musical" and "smooth".
Impressively it does have quicker transients than the WA5, making it the faster more "Stax" like amp. It sounds lighter and less muddy or "lush" for that reason.
As to the cons or things I expect more from the amp, I tend to think that there is a noticeable reduction in bass quantity from the WA5 but better bass texture. I do not think it hits as hard as the WA5 at all. I have not been able to assess bass extension yet. But it does have less bass bloom and may be regarded as more natural. I do not think it detracts from enjoyment though looking at a whole. I suspect modern 45 tubes such as the EML 45 might give the 445 more bass weight.
There is also less extension to the highs, as discussed above it is ever so slightly recessed in the upper mids to highs. Cymbals still sound sparkling though. This is more or less subjective as I do enjoy how this aspect renders a much smoother sound as a whole.
Finally, I agree with others who say this is a bright amp. It is tonally bright but neither sibilant nor harsh. Certainly it is not so bright that I cannot enjoy the stock HD800 with it. Sibilance and lack of smoothness are reasons my HD800s have been seldom used with by WA5. To the contrary, 445's smoothness makes it a perfect match for the HD800.
I have no doubt that it is the better amp compared to the WA5, but honestly I expected it to be MUCH better given the rave reviews. The reality is both amps when using premium tubes sound more similar than different. But this is a good thing, as I was in fact afraid that the 445 would sound too solid statey for my taste. No, it is still a tube amp, with warmth and lushness that makes tubes so desirable.
Finally, I would say it is not a coloured or euphonic amp. Maybe tube rolling will help, but I have not got any goosebumps yet, though I did think to myself "God, this is really good" once or twice today.
I will need to do more listening and real SPL matched A-Bing between the two amps, but these are my initial impressions.
transformers sitting behind the ' tubes ? 
