Hi,
I replaced the stock chips with PCM56P "K" grade. They are made in Korea, not japanese, but I think thay are "BB" original.
First, I want to say that it was very fair what has been reportet on the forum. The changed in terms of rezolution, better transparency, deeper and powerfull low frequents, better instruments separation, focus and stage present, are all affected by chip upgrade. The changed is critical, so the stock chips replacement is justified and very welcome.
Second, I want to mention what kind of changes I realized in Havana (and major importance):
1. Change stock chips with Burr-Brown PCM56P "K" grade,
2. Change the tube with Western Electric (JW) 396A tube
3. Replace stock output capacitors with V-Cap OIMP
4. Replace connectors with WBT "Pure silver" (RCA) high-quality connectors
5. Modded Hiface (M2Tech) transport with two rechargeable batteries, with separate power to usb interface and oscilator, for lower jitter.
6. Source! that is very important in my opinion. Currently I use the "Pure Music" player, which is installed on Apple iMac computer (Snow Leopard SO). I listened as well other players as Amarra, Audacity, Audirvana, but it seems that i like "Pure Music" some more.
They are of course other changes as fuse, "Hi-Fi tuning fuse", EAT-Cool tube dumper, diodes, damping materials and isolation feet, but they are less critical. I have not change until now the film and the electrolytic capacitors, although I think the replacement will be less important compared with those mentioned. I think that Rubycon Blackgate or Silmic II Elna are better compared with Nichicon capacitors, but Blackgate capacitors are not cheap.
I am very, very glad that I realized these upgrade's in Havana, first for better sound quality. In term of classical music or jazz&blues, Havana sounds lovely with STAX headphones. Is something You play much emotion and refinement. Music listening is very pleasant and relaxed, with a clear feeling of extinction of the ear headphones! What remains is the privacy of the artist and instruments.
Thank's and we wish pleasant listening.