no luck for me...I have had a mixed experience with the Havana...
The good part: MHDT Lab. I do not think I have ever gotten better customer support than with Lin-Li and Jiun-Hsien.
How it started: I expressed some interest for the Havana through email exchange with MHDT Lab. Next thing I knew, a package from China was knocking at my door. I HAD NOT EVEN PAID FOR THE UNIT!! Actually, I believe that part was a mistake, but Lin-Li did not freak out or anything, he was patient.
Meanwhile, the bad part of the story comes... Unlucky me, I happen to have several audio tracks that just did not sound right with the Havana. To cut the story short, I would hear significant hiss and "crackle" on the right channel when the music balance was toward the left channel (thus right channel supposed to be quieter).
We worked through various potential culprits like a bad tube (fortunately I had a spare TungSol, and it exhibit the same issue), computer related issue (but this happened regardless of the input and on both my imac and PC laptop), faulty DAC (I flipped the left and right channel DACs but that did not solve / flip the problem).
Next big surprise, I receive a SECOND unit by mail (I still haven't even paid for the first one)! Talk about no compromise customer support! Unfortunately, this time, the noise was on the left channel.
I finally sent both unit backs to MHDT lab, sadly because apart from this issue, I actually truly love the sound of the DAC (it beats the cr*p out of my Black Cube Linear built-in DAC). Very detailed, smooth, deep soundstage, honest bass, dynamic, basically lifelike.
Now comes my 2 cents question to you Havana owners... If you happen to have any of the following audio tracks, do you notice anything like I did?
1. "Touch" from Christopher Hardy on "This is K2 HD Sound": the opening bell sounds highly distorted on the right channel (like it's going through a guitar distortion unit or something!).
2. Beginning of "Monsoon" on Jack Johnson's "Sleep through the static": the hiss and "crackeling" noise is clearly present on the right channel and modulated by the left channel signal (intermittent keyboard).
3. I have a few others but that's an old french audio test CD so nobody is going to have that... I can provide the wav files to anyone who wants them though...
Note that I created "flipped version of the tracks" with left and right channels inverted. I thought that maybe that would make the hiss / distortion switch to the left channel. But that was not the case, still the problem is heard on the right channel (with the original DAC unit they sent).
When I sent the units back to MHDT (and they reimbursed me the shipping fees by paypal! Kudos MHDT), I included and audio CD with the above excerpts. I haven't heard from them (I feel for them though, as they spent so much time for my case already).
My conclusion at this time, is that unfortunately, there might be a flaw in the design philosophy of the DAC... In particular, I can imagine you can have a more transparent signal by including the minimum amount of processing after the D/A conversion, such as skipping low pass filtering. But in my experience with the Havana, I have a feeling the low level distortion / noise heard on the right channel (or left depending on the unit somehow) might be an illustration of the spurious noise not filtered by the DAC. But man, I would be curious to see measuremements on the DAC because I could CLEARLY hear the problem, so we're not talking -80dB noise here, maybe -20dB at most!
Anyhow, Havana owners, I am hoping to hear your experience!