Listening to the Havana right now.
I'm the second owner but the previous owner used it only for a few hours, so probably some break-in is till needed.
It comes with the stock tube.
Sonos ZP90 --> Havana (coax) --> WA3 (Cardas 300b) -->HD650 (Zu Mobius)
I also have a netbook with MPD 0.16 to try the USB connection.
I listen mainly to classical music.
In the last 15 months I tried many DACs: Little Dot DAC_I, V-DAC, DacMagic, X-DAC V3, HRT Music Streamer, Audio-GD Ref.5 and I'm currently using a Valab Luxury. The Valab has been (and it still is) a real love, and my introduction to the NOS world. As I said in a different thread I prefer the Valab to the Ref.5.
First impression of the Havana is...it sounds closer to the Ref.5 than to the Valab!
There's a great control in the low and high end: percussion and cellos sound more clean and less bloated, transients are slower, with a smaller dynamic impact.
The stage isn't wider, but deeper, while the Valab has a more intimate presentation. The Valab has also better mycrodynamics: with string quartets you can "feel" the bow over the strings, and you can touch them during the pizzicatos. The Havana sounds softer, and to my ears less detailed.
Where the Havana is absolutely superior is with large orchestra works. Beethoven's 5th (deutsche grammophon, karlos kleiber) is exemplar, never heard so well: a lot of air between instruments and perfect control over percussions. Brasses are particularly great, they don't tend to cover the rest of the orchestra, they are part of it. With the Valab and the Ref.5 they weren't so natural, they sound raw. The result is amazing with period instruments: Beethoven's 7th (van immerseel and anima eterna orchestra) left me speechless.
Going back to listen now!